Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/10/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
230 PM MST FRI MAY 8 2015
.SYNOPSIS...A WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA
THROUGH SATURDAY BRINGING GUSTY WINDS...COOLER TEMPERATURES AND A
FEW SHOWERS OR THUNDERSTORMS MAINLY NORTH OF TUCSON. THEREAFTER...
DRY AND WARMER WEATHER WILL RETURN SUNDAY THROUGH THE MIDDLE OF NEXT
WEEK.
&&
.DISCUSSION...ISOLATED TO SCATTERED SHOWERS WERE DEVELOPING ACROSS
NORTHERN AND CENTRAL ARIZONA THIS AFTERNOON AS A LOW PRESSURE SYSTEM
OVER SOUTHERN NEVADA APPROACHES. MODELS KEEP THE BEST CHANCE OF
SHOWERS OR THUNDERSTORMS ACROSS NORTHERN ARIZONA INTO THE WHITE
MOUNTAINS. LATEST HRRR SOLUTION SHOWED A FEW SHOWERS FARTHER SOUTH
INTO PINAL AND PIMA COUNTIES. BASED ON RECENT TRENDS IN THE
SATELLITE AND RADAR IMAGERY...WILL INTRODUCE POP VALUES FARTHER
SOUTH THAN PREVIOUSLY FORECAST. OTHERWISE...WIND SPEEDS WILL TAPER
OFF LATER THIS EVENING MOST AREAS AS THE SYSTEM PASSES THROUGH
NORTHERN ARIZONA. WILL KEEP SOME LINGER SHOWERS IN THE WHITE
MOUNTAINS ON SATURDAY INTO SUNDAY...BUT DRY AND COOL FOR THIS TIME
OF YEAR ELSEWHERE. MODELS WARM DAYTIME TEMPERATURES BACK UP TO NEAR
SEASONAL READINGS EARLY NEXT WEEK AS A RIDGE OF HIGH PRESSURE ALOFT
BUILDS OVER THE AREA. THIS RIDGE WILL SHIFT EASTWARD BY THE MIDDLE
OF NEXT WEEK AS A SYSTEM APPROACHES THE WEST COAST.
&&
.AVIATION...VALID THRU 10/00Z. MAINLY SCT TO OCCASIONALLY BKN CLOUD
COVERAGE AT 4-7K FT AGL WILL CONTINUE INTO SATURDAY AS AN AREA OF
LOW PRESSURE MOVES ACROSS ARIZONA. ISOLD -SHRA/-TSRA PSBL MAINLY
NORTH OF KTUS THROUGH THE PERIOD. GUSTY WINDS WILL CONTINUE INTO
THIS EVENING WITH THE STRONGEST WINDS AT KDUG AND KOLS WITH SPEEDS
EXPECTED TO RANGE FROM 20 TO 25 KNOTS...WITH GUSTS OF 30 TO 35 KTS.
WINDS WILL BECOME GENERALLY LESS THAN 10 KNOTS AFTER 09/06Z BEFORE
WESTERLY WINDS INCREASE TO 10 TO 15 KTS SATURDAY AFTER 18Z. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...GUSTY WINDS WILL CONTINUE THROUGH SUNSET...
ESPECIALLY SOUTH AND EAST OF TUCSON. THIS...ALONG WITH SLIGHTLY
LOWER RH VALUES WILL RESULT IN SOME RED FLAG TO NEAR RED FLAG
CONDITIONS ACROSS THE EASTERN HALF OF COCHISE COUNTY AND
SOUTHEASTERN GRAHAM AND GREENLEE COUNTIES. MODERATE FUEL MOISTURE IN
COMBINATION WITH BORDERLINE RH VALUES WILL RESULT IN MARGINAL AND
SPOTTY RED FLAG CONDITIONS OVERALL. THE LOW PRESSURE RESULTING IN
THESE WINDS WILL ALSO RESULT IN A SLIGHT CHANCE OF SHOWERS MAINLY
NORTH OF TUCSON INTO THIS EVENING.
LIGHTER WINDS ARE EXPECTED SATURDAY WITH A THREAT OF A FEW SHOWERS
AND THUNDERSTORMS MAINLY NORTH OF TUCSON AS THE LOW PRESSURE SYSTEM
MOVES NORTH OF THE AREA. FOR SUNDAY THROUGH THURSDAY WARMER AND DRY
WEATHER IS EXPECTED WITH TYPICAL DIURNAL WINDS ACROSS THE REGION.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
405 PM MDT FRI MAY 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 225 PM MDT FRI MAY 8 2015
STRONG UPPER LEVEL LOW IS CURRENTLY OVER LAS VEGAS MOVING SLOWLY
EASTWARD. AHEAD OF THIS SYSTEM THERE HAVE BEEN A COUPLE OF
DISTINCT WAVES THAT ORGANIZED THE PRECIPITATION TODAY. ONE MOVED
BY EARLIER AND THE SECOND IS MOVING NORTHWARD ACROSS THE FORECAST
AREA RIGHT NOW. THERE IS SOME CLEARING BEHIND THE SECOND WAVE BUT
ALL MODELS HAVE ANOTHER WAVE OF UPPER LEVEL FORCING WILL BE
MOVING NORTH FROM SOUTHEAST COLORADO OVERNIGHT. THIS FEATURE WAS
SEEN NICELY IN THE CIRA SYNTHETIC IMAGERY FROM THE NAM NEST
OVERLAID WITH SOME FORCING FIELDS ON AWIPS. WITH THIS EXPECT
INCREASE IN SHOWER ACTIVITY ACROSS THE PLAINS OVERNIGHT AS SEEN IN
THE HRRR RUNS OF LATE AND INCREASED POPS FROM SOUTH TO NORTH TO
LIKELY BEFORE DECREASING THEM AGAIN LATER TONIGHT FROM SOUTH TO
NORTH. RAINFALL AMOUNTS COULD BE AS HIGH AS AN INCH OR SO IN SOME
AREAS BUT NO REAL FOCUS INDICATED AT THIS TIME TO WARRANT ANY
HYDROLOGY HIGHLIGHTS BEYOND WHAT HAS BEEN PUT OUT AT THIS TIME.
A VERY ACTIVE DAY IN STORE FOR SATURDAY WITH ALL KINDS OF WEATHER
ACROSS THE AREA. MODELS ARE IN GENERAL AGREEMENT IN MOVING THE
UPPER LEVEL LOW NORTHEASTWARD ACROSS THE 4 CORNERS REGION AND INTO
EASTERN COLORADO BY THE END OF THE DAY. THIS WILL BRING OF COURSE
A LARGE AMOUNT OF UPPER LEVEL FORCING WITH IT...FIRST ACROSS THE
MOUNTAINS AND THEN INTO EASTERN COLORADO BY THE AFTERNOON. THE 700
MB LOW INITIALLY STARTS OUT RATHER ELONGATED BUT THEN WITH RAPID
CYCLOGENESIS EAST OF THE MOUNTAINS IT CONSOLIDATES NEAR LIMON
AFTER 00Z/SUNDAY. OROGRAPHIC FLOW WILL NOT BE FAVORABLE IN THE
MOUNTAINS WEST OF THE DIVIDE UNTIL THE UPPER LOW PASSES BY SAT
NIGHT BUT WITH THE STRONG DYNAMICS SHOULD SEE SNOW INCREASE WITH
EMBEDDED THUNDERSTORMS AS THE DAY GOES ON. FOR NOW KEPT THE WATCH
AS IS BUT WOULD LIKELY BE ENOUGH TO HOIST A WARNING ALTHOUGH
LOWERED OVERALL AMOUNTS TO 8 TO 16 INCHES TOTAL. SOME ADDITIONAL
SNOW TONIGHT BUT MORE SCATTERED IN COVERAGE WITH SNOW LEVEL DOWN
TO AROUND 9000 FEET. ON THE PLAINS SHOULD BE A LULL IN THE
PRECIPITATION IN THE MORNING WITH SOME PARTIAL CLEARING THAT COULD
SET THE STAGE FOR SEVERE WEATHER AS THE SYSTEM REDEVELOPS EAST OF
THE MOUNTAINS. BEST CHANCES FOR SEVERE WOULD LIKELY BE MORE TO THE
EASTERN PART OF THE PLAINS BUT COULD GET ALL THE WAY BACK TO THE
URBAN CORRIDOR. THEN UPSLOPE SHOULD INCREASE LATE WITH MORE
WIDESPREAD PRECIPITATION DEVELOPING FROM NORTH TO SOUTH LATER IN
THE AFTERNOON. SNOW CHANCES AT LOWER ELEVATIONS COME LATER IN THE
PERIOD AS COLDER AIR COMES IN ON THE BACKSIDE OF THE SYSTEM.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 225 PM MDT FRI MAY 8 2015
STRONG UPPER LOW WILL MOVE FROM SOUTH CENTRAL COLORADO 00Z SUNDAY TO
SOUTHWEST NEBRASKA 12Z SUNDAY. THE SURFACE LOW WILL TRACK TO THE
NORTHEAST OF THE UPPER LEVEL LOW. STRONG TO SEVERE STORMS MAY LINGER
INTO THE EARLY EVENING HOURS OVER THE PLAINS. AFTER THIS...A
DEFORMATION ZONE WILL DEVELOP ON THE BACKSIDE OF THE LOW.
PRECIPITATION WILL START OFF AS RAIN...BUT QUICKLY TURN TO SNOW
SATURDAY EVENING ACROSS THE PLAINS. UNCERTAIN WHERE THIS ZONE WILL
FORM...BASED ON SLIGHTLY DIFFERENT STORM TRACKS. EXPECT MOST AREAS
TO SEE PERIOD OF SNOW...WITH A SMALL BAND OF 3 TO 6 INCHES OF
SNOWFALL EAST OF I-25 BY SUNDAY MORNING.
RAIN AND SNOW WILL END SUNDAY MORNING AS THE LOW LIFTS NORTHEAST OF
THE REGION. IT WILL BE CLOUDY A COOL BEHIND THE SYSTEM WITH HIGHS
MAINLY IN THE 40S. IT WILL BE SLIGHTLY UNSTABLE IN THE MOUNTAINS
WITH ISOLATED/SCATTERED SNOW SHOWERS. FOR SUNDAY NIGHT...FROST WILL
BE LIKELY MOST LOCATIONS AS SKIES PARTIALLY CLEAR. EXPECT LOW ACROSS
THE AREA TO BE IN THE 20S TO LOWER 30S.
FOR EARLY NEXT WEEK...UPPER LEVEL RIDGE WILL MOVE ACROSS THE REGION
MONDAY AND MONDAY NIGHT. THIS WILL BRINGING DRIER CONDITIONS TO THE
AREA. STILL A SLIGHT CHANCE FOR SHOWERS OVER THE MOUNTAINS...
OTHERWISE DRY CONDITIONS WILL PREVAIL. IT WILL BE COOL MONDAY BEHIND
THE EXITING LOW WITH HIGHS IN THE 50S TO LOWER 60S ACROSS NORTHEAST
COLORADO.
ON TUESDAY...FLOW ALOFT WILL BECOME SOUTHWESTERLY AS AN UPPER LEVEL
LOW DIGS SOUTH ALONG THE CALIFORNIA COAST. TEMPERATURES WILL WARM
INTO THE 60S TUESDAY UNDER THE SOUTHWESTERLY. MAY BE ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS ACROSS THE AREA.
THE LOW WILL WEAKEN AND LIFT NORTHEAST ACROSS THE INTERMOUNTAIN WEST
ON WEDNESDAY. AS THE TROUGH AXIS MOVES ACROSS THE REGION...EXPECT IT
TO PRODUCE SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS. WILL
BUMP POPS UP INTO THE SCATTERED RANGE FOR THIS. TEMPERATURES WILL
ALSO WARM AS A SOUTH TO SOUTHWEST FLOW PREVAILS.
FOR THURSDAY AND FRIDAY...ANOTHER UPPER LEVEL LOW MOVES OVER
CALIFORNIA. THIS WILL KEEP A SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL
ROCKIES. THERE IS A SHORT WAVE RIDGE FOLLOWING WEDNESDAY`S SYSTEM.
WILL BE TRICKY TO TIME THIS...BUT THERE SHOULD BE A WINDOW WHERE IT
WILL BE DRY ACROSS THE AREA. ONCE THIS RIDGE SHIFTS EAST OF THE
AREA. EXPECTED SCATTERED/ISOLATED SHOWERS AND THUNDERSTORMS TO
RETURN TO THE REGION. WILL GO WITH ISOLATED TO SCATTERED POPS FOR
THURSDAY AND FRIDAY...WITH THE LOWER POPS ON THURSDAY WHEN THIS
RIDGE MAY MOVE ACROSS THE AREA. TEMPERATURES WILL REMAIN COOL WITH
HIGHS IN THE 60S...SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z SATURDAY LATE AFTERNOON)
ISSUED AT 225 PM MDT FRI MAY 8 2015
A LINE OF THUNDERSTORMS MOVING THROUGH THE METRO AREA WILL SHIFT
TO THE NORTH BY 22Z...SO SHOULD SEE CIGS/VSBYS IMPROVE
SIGNIFICANTLY AT THAT TIME. WL KEEP IFR/MVFR CIGS WITH THE TSTMS.
THE SE-ELY WINDS STILL PROGGED THIS EVENING AND OVERNIGHT.
ADDITIONAL LIGHT SHOWERS MAY RETURN LATER THIS EVENING. CIGS WL
LOWER AT THAT TIME...WITH IFR/MVFR CONDITIONS REDEVELOPING AFTER
06Z. ENELY WINDS MAY INCREASE SATURDAY MORNING WITH THE SURFACE
LOW INTENSIFYING OVER SERN CO. STORM THAT DEVELOP LATE SATURDAY
MORNING/AFTN COULD BE STRONG...WITH SEVERE POTENTIAL TO THE SOUTH
AND EAST OF DENVER.
&&
.HYDROLOGY...
ISSUED AT 225 PM MDT FRI MAY 8 2015
THUNDERSTORMS PRODUCING VERY HEAVY RAINFALL IN THE DENVER AREA
SHOULD WEAKEN AS THEY SHIFT NORTHWARD. A FLOOD ADVISORY IS IN
EFFECT FROM THE FRONT RANGE FOOTHILLS EASTWARD DOWN THE SOUTH
PLATTE RIVER THROUGH 11 PM SUNDAY NIGHT TO ACCOUNT FOR ALL THE
CURRENT AND FUTURE RUNOFF OVER THE WEEKEND. STORMS/SHOWERS MAY
REDEVELOP OVERNIGHT WITH GENERALLY LIGHT RAINFALL EXPECTED. ON
SATURDAY AFTERNOON AND EVENING...ADDITIONAL SHOWERS/TSTMS AS A
STRONGER TROUGH MOVES ACROSS COLORADO. STREAMS WILL CONTINUE TO
RUN HIGH WITH MODERATE TO HEAVY RAIN SHOWERS DEVELOPING IN THE IN
THE FOOTHILLS AND THE NORTHEAST PLAINS SATURDAY AFTERNOON AND
SATURDAY NIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY
NIGHT FOR COZ033-034.
FLOOD ADVISORY IN EFFECT THROUGH 11 PM MDT SUNDAY NIGHT FOR
MORGAN...CENTRAL LOGAN...JEFFERSON...SEDGWICK...WASHINGTON...
BROOMFIELD...EASTERN GILPIN...EASTERN LARIMER...ELBERT...DOUGLAS
..SOUTHEAST CLEAR CREEK...ADAMS...BOULDER...DENVER...ARAPAHOE AND
WELD COUNTIES.
$$
SHORT TERM...SZOKE
LONG TERM...MEIER
AVIATION...COOPER
HYDROLOGY...COOPER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
402 PM MDT FRI MAY 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 210 PM MDT FRI MAY 8 2015
CURRENTLY...SIGNIFICANT INSTABILITY HAS DEVELOPED ACROSS THE
SOUTHERN I-25 CORRIDOR WHERE STRATUS CLEARED EARLY...WITH LAPS
CAPES RUNNING OVER 2000 J/KG. 0-6KM SHEAR SUFFICIENT FOR ROTATING
CONVECTION...WITH 2 PERSISTENT SUPERCELLS SOUTH OF PUEBLO AS OF
2130Z. STRONGEST CONVECTION NEXT 1-3 HOURS WILL LIKELY BE ACROSS
PUEBLO/LAS ANIMAS/CROWLEY/OTERO COUNTIES WHERE INSTABILITY IS
GREATEST...WITH HRRR KEEPING STRONG CONVECTION GOING OVER
SOUTHEAST PUEBLO COUNTY WELL INTO THE EVENING. FARTHER NORTH
AROUND COLORADO SPRINGS...CLOUDS AND EARLY MORNING CONVECTION HAVE
HELD DOWN INSTABILITY SOMEWHAT....THOUGH STORMS HAVE BEEN ABLE TO
PRODUCE VOLUMINOUS SMALL HAIL ONCE AGAIN. MOUNTAINS WILL SEE ONLY
ISOLATED STORMS...AND FAR EASTERN PLAINS NEAR THE KS BORDER LOOK
TOO STABLE FOR MUCH DEEP CONVECTION...AT LEAST INTO THE EARLY EVENING.
TONIGHT...CONVECTION ALONG I-25 CORRIDOR WILL CONTINUE PAST
SUNSET...WITH WEAKENING STORMS SHIFTING TOWARD THE KS BORDER
BY MIDNIGHT. SEVERE THREAT WILL CONTINUE SOUTHERN I-25
CORRIDOR...WITH TORNADO WATCH UNTIL 03Z LOOKING REASONABLE. MAY
SEE SOME SORT OF MCS LIFT OUT OF THE TX PANH SAT MORNING....AND
WILL INCREASE POPS OVER THE PLAINS TO ACCOUNT FOR THIS
POSSIBILITY. LIFT INCREASES OVER CONTINENTAL DIVIDE AS UPPER LOW
APPROACHES...WITH AT LEAST SOME LIGHT SNOW OVER THE HIGHER PEAKS
BY MORNING.
SATURDAY...STILL NOT A CLEAR CUT SOLUTION REGARDING POSITION OF
SURFACE LOW AND HOW FAR WEST LOW LEVEL MOISTURE/INSTABILITY WILL
REMAIN IN THE AFTERNOON. GFS/ECMWF LIFT SURFACE LOW AND WARM FRONT
NORTH OF THE PALMER DIVIDE BY AFTERNOON WITH DRYLINE PUNCHING INTO
KS BY SAT EVENING. LAST COUPLE RUNS OF THE NAM KEEP THE SURFACE
LOW SOUTH OF KLHX UNTIL EARLY EVENING...WHICH KEEPS SURFACE AXIS
OF DEEP INSTABILITY/MOISTURE FARTHER WEST AND ALLOWS AT LEAST
SOME MODERATELY UNSTABLE AIR TO WRAP BACK INTO PUEBLO/EL PASO
COUNTIES LATE. WILL LEAN TOWARD THE HIGHER TERRAIN RESOLUTION NAM
AT THIS POINT AS CLIMATOLOGY SUPPORTS ITS SURFACE LOW POSITION
NEAR KLHX...AND POSSIBLE EARLY MORNING CONVECTION ALONG THE KS
BORDER MAY PUSH MOIST AIR WESTWARD FOR A TIME SAT MORNING. IF
MOISTURE HOLDS IN PLACE...MASSIVE SHEAR (0-6KM SHEAR 60-70 KTS)
WILL LEAD TO SEVERE STORMS OVER THE FAR EASTERN PLAINS WITH EVEN
SOME STRONGER STORMS POSSIBLE BACK TOWARD PUEBLO AND COLORADO
SPRINGS AS STRONG LIFT WRAPS BACK AROUND THE UPPER LOW.
OVERALL...WILL KEEP POPS IN PLACE ALL DAY OVER THE FAR EASTERN
PLAINS...WITH CONVECTION POSSIBLE EARLY IN THE MORNING AND A
SECOND ROUND OF STORMS IN THE AFTERNOON. EASTERN MOUNTAINS/I-25
CORRIDOR WILL SEE A DRY PERIOD THROUGH THE MORNING AS WLY
DOWNSLOPE INCREASES...THEN AN INCREASING CHANCE OF PRECIP BY
AFTERNOON AS LOW LIFTS OUT AND STRONGER LIFT DEVELOPS UNDER THE
TROWAL. REMAINING MOUNTAINS AND VALLEYS WILL SEE SCT TSRA...WITH
HEAVY SNOW OVER THE HIGHER PEAKS. KEPT WINTER STORM WATCH IN PLACE
FOR CENTRAL MOUNTAINS SAT...AND HOISTED A NEW WATCH FOR THE SUMMIT
OF PIKES PEAK WHERE 1 TO 2 FEET OF NEW SNOW LOOKS POSSIBLE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 210 PM MDT FRI MAY 8 2015
...ACTIVE WEATHER PATTERN IN PLACE OVER THE WEEKEND...
SATURDAY NIGHT THROUGH SUNDAY...MODELS INDICATE THAT THE UPPER LOW
WILL BE LOCATED OVER SOUTH-CENTRAL CO SAT EVENING...AND WILL QUICKLY
EJECT TO THE NE TO NEBRASKA SUN MORNING...THEN SOUTH DAKOTA SUN
NIGHT. ACTIVITY SHOULD BE SLIGHTLY SUBDUED ACROSS THE SE PLAINS SAT
NIGHT AS THE LOW MOVES NE...BUT WRAPAROUND WILL START AFFECTING THE
PALMER DVD AND RAMPART RANGE. CATEGORICAL SHOWERS ARE FORECAST OVER
MONUMENT HILL SAT EVE...WITH DROPPING TEMPS SWITCHING THE PCPN OVER
TO SNOW OVERNIGHT. UP TO 2 INCHES OF NEW SNOW WILL BE POSSIBLE FOR
MONUMENT HILL BY SUN MORNING...BUT HIGHER AMOUNTS WILL BE POSSIBLE
FOR TELLER COUNTY AND ESPECIALLY PIKES PEAK SO THE PEAK HAS BEEN
INCLUDED IN THE WINTER STORM WATCH. AS THE SYSTEM CONTINUES PULLING
AWAY LATE SUN...SHOWER AND STORM ACTIVITY IS EXPECTED TO DIMINISH.
LOOK FOR MAX TEMPS IN THE 50S TO AROUND 60F FOR MOST AREAS ON
SUN...WITH OVERNIGHT MIN TEMPS IN THE LOWER TO MID 30S.
MONDAY THROUGH WEDNESDAY...TEMPORARY RIDGING OVER THE STATE MON WILL
GIVE WAY TO A SW FLOW ALOFT ON TUE. RESIDUAL MOISTURE IS EXPECTED TO
SPARK MORE SHOWER AND STORM ACTIVITY MON AFTN AND EVE...THEN AS THE
SW FLOW SETTLES IN FOR TUE A PLUME OF GULF MOISTURE WILL BE DRAWN UP
ACROSS NM AND INTO COLORADO. THE BEST WINDOW FOR STORM ACTIVITY WILL
OCCUR TUE AND WED...WITH THE EMPHASIS ON TUE. STORMS WILL INITIATE
OVER THE HIGHER TERRAIN BOTH DAYS BY LATE MORNING...THEN TRACK E-NE
OVER THE ADJACENT PLAINS THROUGH THE AFTN AND EVE. LOOK FOR MAX
TEMPS TO WARM MON THROUGH WED WITH 60S ON MON TO MID TO UPPER 70S BY
WED.
THURSDAY AND FRIDAY...SW FLOW ALOFT REMAINS IN PLACE THROUGH THE
REST OF THE WORK WEEK...WITH MAX TEMPS IN THE 70S CONTINUING. THE
PLUME OF GULF MOISTURE IS FORECAST TO SLIDE TO THE EAST OUT OF THE
REGION...SO STORM ACTIVITY WILL BECOME MORE ISOLATED AND DIURNAL IN
NATURE AND TIED MORE TO THE HIGHER TERRAIN. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 210 PM MDT FRI MAY 8 2015
AT KCOS...MVFR CONDITIONS THROUGH THE NIGHT WITH OCCASIONAL
-SHRA/-TSRA AND PERIODS OF IFR UNDER HEAVIER PRECIP LOW CLOUDS
CLEAR BRIEFLY BY LATE MORNING SAT AS STRONGER SOUTH WINDS
DEVELOP...BEFORE A RENEWED CHANCE OF SHOWERS AND THUNDERSTORMS
RETURNS INT THE AFTERNOON.
AT KPUB...EXPECT PATCHY MVFR MVFR CONDITIONS INTO THE EVENING AND
OVERNIGHT WITH STRONG CONVECTION AND PERIODS OF BRIEF IFR CLOSE
TO THE TERMINAL UNTIL AT LEAST 03Z. OVERNIGHT...STILL LOW THREAT
OF OCCASIONAL -SHRA/-TSRA WITH UNTIL 06Z-09THEN LOWER CLOUDS
SHOULD FINALLY CLEAR BY LATE MORNING SAT AS STRONGER SOUTH WINDS
DEVELOP.
AT KALS...VFR CONDITIONS EXPECTED THE NEXT 24 HRS LOW CHANCE OF
TSRA OVERNIGHT AND THROUGH THE DAY SAT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY
NIGHT FOR COZ058-060-061-082.
&&
$$
SHORT TERM...MOORE
LONG TERM...PETERSEN
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 PM MDT THU MAY 7 2015
.UPDATE...
ISSUED AT 900 PM MDT THU MAY 7 2015
NOW THAT THE TORNADO THREAT HAS EXITED...TIME TO ISSUE A
WINTER STORM WATCH. WILL PUT OUT FOR THE CONTDVD...SAWATCH
AND MOSQUITO RANGE...TO MATCH EXISTING WATCHES PUT OUT BY
WFOS GJT AND BOU. SNOW AMOUNTS MAY BE SOMEWHAT MARGINAL IN THE
GRIDS...BUT GIVEN THAT THIS IS HEADING INTO THE MIDDLE OF MAY
IT`S CLOSE TO A LATE SEASON EVENT AND POTENTIAL WARNING SEEMS
JUSTIFIED. ROSE
UPDATE ISSUED AT 539 PM MDT THU MAY 7 2015
UPDATED MAINLY POPS PER CURRENT WSR TRENDS AND LATEST HI RES
GUIDANCE. LOOKS LIKE A BROKEN LINE OF STORMS WILL BUILD OVER
THE I-25 CORRIDOR...THEN MOVE E THIS EVENING. EXPECT LOWERING
CIGS OVER THE AREA WITH PRECIP REDEVELOPING OVER NRN I-25
AND THE SRN FRONT RANGE LATE THIS EVENING AND OVERNIGHT. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 212 PM MDT THU MAY 7 2015
CURRENTLY...STEEP LOW LEVEL LAPSE RATES...FAIRLY COLD AIR ALOFT
AND SURFACE CAPES OVER 1000 J/KG HAVE COMBINED TO GENERATE VERY
EFFICIENT HAIL PRODUCING TSRA ACROSS EL PASO COUNTY...WITH 6-8 INCH
DEEP ACCUMULATIONS SLOWING TRAFFIC AND CAUSING DRAINAGE PROBLEMS
OVER THE NORTH SIDE OF COLORADO SPRINGS. TOUGH TO FIND MUCH UPPER
LEVEL FORCING...THOUGH THERE IS A HINT OF A WEAK SHORT WAVE LIFTING
NORTHEASTWARD THROUGH THE FOUR CORNERS IN THE LATEST WATER VAPOR
LOOP. ELSEWHERE ON THE PLAINS...CAPES RUNNING 1000-1500 J/KG....WITH
BEST INSTABILITY SOUTH OF THE ARKANSAS RIVER WHERE STRATUS CLEARED
FASTEST EARLIER THIS MORNING. FOR THE REMAINDER OF THE
AFTERNOON...SVR TSRA WATCH ISSUED FOR PLAINS ALONG AND EAST OF I-25
WITH MAIN THREAT BEING LARGE HAIL...THOUGH ISOLATED CELLS ACROSS LAS
ANIMAS/BACA COUNTIES HAVE SHOWN SOME SUPERCELLULAR CHARACTERISTICS
WITH A LEAST A LOW THREAT OF A TORNADO.
TONIGHT...TSRA MIGRATE EASTWARD THIS EVENING...WITH LATEST HRRR
KEEPING STRONGEST STORMS ALONG THE PALMER DIVIDE AND ACROSS LAS
ANIMAS/BACA COUNTIES THROUGH THE EVENING BEFORE A LOOSELY ORGANIZED
LINE FORMS NEAR THE KS BORDER LATER IN THE EVENING. HRRR ALSO HINTS
AT A NEW ROUND OF CONVECTION ALONG THE I-25 CORRIDOR IN PUEBLO/EL
PASO COUNTIES 05Z-06Z AS OUTFLOW ENHANCED UPSLOPE FLOW PUSHES BACK
WESTWARD. OVERALL...WILL KEEP POPS IN PLACE MOST LOCATIONS THROUGH
THE NIGHT...HIGHEST CHANCES EL PASO/TELLER COUNTIES.
THURSDAY...STILL A FEW LINGERING -SHRA DURING THE MORNING WITH LOW
LEVEL MOISTURE/UPSLOPE AND WEAK WARM ADVECTION LIFT DEVELOPING OVER
THE OLD FRONTAL BOUNDARY. BY AFTERNOON...EXPECT WARM FRONT TO LIE
ALONG THE NM BORDER AROUND MIDDAY BEFORE LIFTING NORTHWARD TOWARD
THE ARK RIVER BY EVENING. ALONG AND NORTH OF THE BOUNDARY...EASTERLY
BL FLOW COMBINED WITH FAIRLY DEEP INSTABILITY WILL LEAD TO ANOTHER
ROUND OF STRONG TO SEVERE THUNDERSTORMS AS CAPES RANGE FROM 1-2K
J/KG AND 0-6KM SHEAR APPROACHES 50 KTS. ELSEWHERE OVER THE MOUNTAINS
AND HIGH VALLEYS...LITTLE CHANGE IN THE PATTERN AS SCT AFTERNOON
TSRA WILL DEVELOP ONCE AGAIN...WITH HIGHEST POPS GENERALLY OVER THE
NORTHERN HALF OF THE AREA. MAX TEMPS LITTLE CHANGED WITH
CLOUDS/MOISTURE/PRECIP PERSISTING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 212 PM MDT THU MAY 7 2015
THERE IS A HIGH DEGREE OF ENSEMBLE SPREAD THROUGH THE EXTENDED
PERIOD WITH ACTIVE WEATHER LOOKING TO CONTINUE FOR THE NEXT
SEVERAL DAYS. CONFIDENCE IN THE FORECAST IS ON THE HIGHER SIDE
THROUGH THE WEEKEND...WITH LESS CONFIDENCE EARLY TO MIDDLE NEXT
WEEK.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...A STRONG UPPER LEVEL LOW
PRESSURE SYSTEM IS FORECAST TO MOVE OUT OF THE DESERT
SOUTHWEST...NORTHEAST ACROSS SOUTHERN COLORADO INTO THE NORTHERN
PLAINS. SEVERAL ROUNDS OF WEATHER ARE EXPECTED WITH THIS STORM
SYSTEM AND PREPARATIONS SHOULD BE MADE FOR MOUNTAIN
SNOWFALL...SEVERE WEATHER ON THE PLAINS AND FLOODING POTENTIAL IN
SATURATED AREAS.
A SHORTWAVE TROUGH WILL BE EJECTING AROUND THE LOW ACROSS
COLORADO FRIDAY NIGHT. EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO
BE ONGOING ACROSS THE REGION. SHEAR AND INSTABILITY WILL BE
SUFFICIENT FOR A FEW STRONG TO SEVERE THUNDERSTORMS FRIDAY
EVENING...ESPECIALLY EAST OF A LA JUNTA TO KIM LINE. STRONG WINDS
AND LARGE HAIL ARE THE PRIMARY THREATS...AND AN ISOLATED TORNADO
IS POSSIBLE. THESE STORMS WILL SHIFT EAST INTO WESTERN KANSAS
THROUGH THE LATE EVENING HOURS. ELSEWHERE...SHOWERS AND
THUNDERSTORMS WILL CONTINUE ACROSS THE MOUNTAINS AND ADJACENT
PLAINS. LOCALLY HEAVY RAINFALL IS POSSIBLE AND SMALL HAIL FRIDAY
EVENING. IF A STRONGER STORM CAN IMPACT TELLER AND EL PASO
COUNTIES...FLASH FLOODING WILL BE POSSIBLE. THIS ACTIVITY SHOULD
CONTINUE THROUGH FRIDAY NIGHT.
THE UPPER LEVEL LOW IS FORECAST TO MOVE NORTHEAST ACROSS SOUTHERN
INTO EASTERN COLORADO ON SATURDAY. SEVERAL CONCERNS AS THE UPPER
SYSTEM EJECTS ACROSS THE AREA...THE POTENTIAL FOR SEVERE WEATHER
ALONG THE KANSAS BORDER...HEAVY RAINFALL WRAPPING AROUND THE
SYSTEM OVER THE PALMER DIVIDE AND INTO THE RAMPART RANGE AND SNOW
LEVELS. ALL OF THESE WEATHER CONCERNS WILL DEPEND ON THE EXACT
STORM PATH. THE NAM AND ECMWF HAVE A MORE FAVORABLE SOUTHERN
SOLUTION...WHILE THE GFS IS SLIGHTLY NORTH AND WOULD LIMIT THE
HEAVY RAINFALL THREAT IN PARTICULAR. AS FOR THE SEVERE WEATHER
THREAT...MODELS ARE IN GOOD AGREEMENT WITH A DRYLINE DEVELOPING
OVER THE EASTERN PLAINS AND TRACKING THROUGH THE AFTERNOON.
CONVECTION IS FORECAST TO DEVELOP ALONG THE DRYLINE DURING THE
AFTERNOON HOURS...AND STORMS THAT DO DEVELOP WILL LIKELY BECOME
SEVERE. THE MAIN QUESTION IS HOW FAR EAST OR WEST THE STORMS
DEVELOP. HAVE A FEELING THE SEVERE WEATHER THREAT WILL BE LIMITED
TO ALONG THE KANSAS BORDER. ELSEWHERE...FLOW BEHIND THE SURFACE
LOW WILL PROVIDE STRONG LOW LEVEL UPSLOPE FLOW OVER THE PALMER
DIVIDE INTO THE RAMPART RANGE. THIS UPSLOPE FLOW COMBINED WITH
ABUNDANT MOISTURE WILL PROVIDE A FOCUS FOR HEAVY RAINFALL ALONG
THE LEE SLOPES OF THE RAMPART RANGE AND PALMER DIVIDE. THESE AREAS
HAVE SEEN HEAVY RAINFALL LATELY AND ARE SATURATED...AND FLOODING
WILL BE POSSIBLE...ESPECIALLY WITH THE ECMWF AND NAM STORM TRACK.
SNOW LEVELS WILL LIKELY BE HIGH THROUGH THE DAY ON SATURDAY WITH
SEVERAL INCHES EXPECTED ABOVE 10 KFT.
THE UPPER LEVEL LOW WILL PULL OFF INTO THE CENTRAL PLAINS SATURDAY
NIGHT INTO SUNDAY. WRAP AROUND FLOW AND SOME MODELS ARE PRODUCING
A TROWAL FEATURE OVER NORTHERN COLORADO KEEPING DECENT
PRECIPITATION ACROSS MUCH OF THE REGION. GFS HAS THIS FEATURE
NORTH...HOWEVER THE ECMWF AND NAM ARE SOUTH AND HAVE THIS FEATURE
IMPACTING THE AREA THROUGH SUNDAY MORNING. COLD AIR WILL BE
FILTERING INTO THE REGION WHICH WILL LIKELY DROP SNOW LEVELS DOWN
TO AROUND 7 KFT SUNDAY MORNING. THIS COULD LEAD TO SNOW ON THE
PALMER DIVIDE AND AN INCH OR TWO OF ACCUMULATION GRASSY SURFACE.
EXPECT MOST AREAS TO SEE CONTINUED SHOWER ACTIVITY IN THE COLD
WRAP AROUND FLOW THROUGHOUT THE DAY ON SUNDAY.
MONDAY THROUGH THURSDAY...THE UPPER SYSTEM WILL BE SHIFTING OFF
TO THE NORTHEAST WITH THE NEXT SYSTEM TAKING SHAPE BY THE MIDDLE
OF THE WEEK. EXPECT CONTINUED SHOWER AND THUNDERSTORM ACTIVITY
EACH AFTERNOON AND EVENING ACROSS THE MOUNTAINS...MOVING OUT IN
THE PLAINS. THE NEXT SYSTEM WILL LIKELY IMPACT THE AREA WEDNESDAY
INTO THURSDAY WITH ANOTHER ROUND OF WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY BY THURSDAY. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1107 PM MDT THU MAY 7 2015
LATEST COMPUTER GUIDANCE SHOWS MUCH STRONGER E TO SE WINDS OVER
THE PLAINS TOMORROW. IF THIS TREND CONTINUES...KCOS COULD
POTENTIALLY BE STUCK IN IFR TO LIFR MUCH OF TOMORROW AND FRI
EVENING. KPUB COULD ALSO SEE AN EXTENDED PERIOD OF MVFR-IFR.
HAVE REMAINED ON THE OPTIMISTIC SIDE IN THE 06Z TAFS...BUT
POTENTIAL FOR PERSISTENT LOW CIGS WILL HAVE TO BE WATCHED.
IF LOW CLOUDS DISSIPATE TOMORROW AFTERNOON...THIS COULD SET
UP THE AREA FOR ANOTHER ROUND OF STRONG TO SVR STORMS...WITH
THE POTENTIAL FOR HEAVY RAIN...GUSTY WINDS AND SMALL HAIL.
WX TRENDS WILL BE HIGHLY DYNAMIC AND RAPIDLY CHANGING THROUGH
TOMORROW EVE...WITH THE POTENTIAL FOR SIGNIFICANT IMPACTS FOR
LOCAL AVIATION. PLEASE MONITOR THE LATEST STATEMENTS AND
ADVISORIES/WARNINGS. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY
NIGHT FOR COZ058-060-061.
&&
$$
UPDATE...ROSE
SHORT TERM...PETERSEN
LONG TERM...MOZLEY
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS ALBANY NY
1034 PM EDT SAT MAY 9 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES...
WILL APPROACH THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO
EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL
BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE
WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL
REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 PM EDT...THE KENX RADAR CONTINUES TO BE QUIET WITH A
FEW SHOWERS AND WEAKENING THUNDERSTORMS UPSTREAM OVER WRN
NY...AND MOVING EAST OF LAKE ONTARIO. THESE ISOLD-SCT SHOWERS ARE
AHEAD OF WEAK DISTURBANCE IN ADVANCE OF THE COLD FRONT. THE
LATEST HRRR CONTINUES TO SHOW SOME LIGHT SHOWERS MOVING ACROSS THE
WRN-SRN ADIRONDACKS AFTER MIDNIGHT. WE HAVE REMOVED THE
THUNDERSTORMS AND KEPT ISOLD-SCT SHOWERS IN THE FCST WITH THE LOSS
OF THE DIURNAL HEATING AND A MORE STABLE ENVIRONMENT.
ALSO WE HAVE ADDED PATCHY FOG TO THE MID HUDSON VALLEY...NW
CT...SE CATSKILLS AND SRN BERKSHIRES BTWN 06Z-12Z. THE LOW STRATUS
CONTINUES TO FORM AND MOVE NORTH FROM THE LOWER TO MID HUDSON
VALLEY AND SW NEW ENGLAND. EXPECT MOSTLY CLOUDY CONDITIONS FROM
THE HUDSON RIVER VALLEY EASTWARD BY DAYBREAK. LOWS TONIGHT WILL BE
VERY MILD FOR EARLY MAY IN THE MID 50S TO LOWER 60S ACROSS THE
FCST AREA. THESE MINS ARE A GOOD 10 TO 15 DEGREES ABOVE NORMAL. A
SOUTHERLY BREEZE WILL CONTINUE IN THE CAPITAL REGION WITH THE
FUNNELING EFFECT UP THE HUDSON VALLEY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
FOR SUNDAY THE COLD FRONT WILL DROP SOUTHWARD ACROSS THE NORTHERN
HALF OF THE AREA DURING THE DAY. THERE WILL BE SCATTERED SHOWERS
AND THUNDERSTORMS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT.
THERE IS A STRONG THETA E RIDGE IN PLACE ACROSS THE REGION WITH
CAPES OVER 1000 J/KG NORTH OF THE GREATER CAPITAL DISTRICT. UPPER
LEVEL Q VECTOR DIVERGENCE IS WEAK AS ARE HELICITY VALUES WHICH ARE
GENERALLY UNDER 100 M2/S2 SO NOT EXPECTING ANY SEVERE WEATHER ON
SUNDAY. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE AS PWATS
REACH ABOVE 1.50 INCHES ACROSS NORTHERN PORTIONS OF THE FA. HIGHS
SUNDAY AFTERNOON ARE EXPECTED TO RANGE FROM THE UPPER 70S
NORTHWEST TO MID 80S SOUTHEAST.
DESPITE LOSS OF DAYTIME HEATING WILL CONTINUE CHANCES FOR SHOWERS
AND THUNDERSTORMS SUNDAY NIGHT AS THE FRONTAL BOUNDARY WILL LIKELY
STALL OVER THE AREA. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO
MID 60S.
BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE
CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING
EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL
TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY
INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN
ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG
THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON
HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25
TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2. HIGHS ON
MONDAY SHOULD BE IN THE UPPER 60S TO LOWER 80S.
MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH
PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE
FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES
EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS
TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA.
SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT
THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE
IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN THE 70S TO
AROUND 80.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED FORECAST FEATURES A RETURN TO MORE SEASONABLE TEMPS FOR
MID MAY FROM THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH MAINLY
DRY WEATHER AFTER WEDNESDAY...AS A CANADIAN SFC HIGH BUILDS IN FOR
THU INTO THE WEEKEND.
TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE EAST OF THE
REGION BY TUESDAY EVENING ACCORDING TO THE MEDIUM RANGE GUIDANCE
/ECMWF...GFS...CAN GGEM/...AND MOST OF THE GEFS. HOWEVER...THE
UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING
ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW
CHC OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN
CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE MUCH COOLER BY WED
MORNING WITH H850 TEMPS FALLING TO +1C TO +4C FROM NW TO SE ACROSS
THE REGION...AND THIS IS BEFORE THE SFC TROUGH PASSAGE. THE COLD
ADVECTION WILL CONTINUE ON WED...AS IT WILL BE BRISK AND COOL. LOWS
WILL BE IN THE MID AND U40S OVER THE MTNS...AND LOWER TO MID 50S
ACROSS THE VALLEY AREAS. HIGHS WED WILL BE SLIGHTLY BELOW NORMAL
WITH U50S TO M60S IN THE VALLEY AREAS...AND U40S TO U50S OVER THE
HIGHER TERRAIN.
WED NIGHT INTO THU...THE TREND TO COOLER AND DRIER WEATHER
CONTINUES...AS THE SHOWERS WILL END BY SUNSET. IN THE COLD ADVECTION
REGIME THE GFS HAS H850 TEMPS LOWER TO -1C TO -4C OVER THE FCST
AREA. THESE H850 TEMPS ARE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL
ACCORDING TO THE LATEST 12Z GEFS. THE SKIES WILL GRADUALLY
CLEAR...AND THE WINDS WILL BE LIGHTER THAN THU. LOWS WILL BE IN THE
40-45F RANGE IN THE CAPITAL DISTRICT...MID HUDSON VALLEY...SRN
TACONICS...ERN WINDHAM CTY VT...AND NW CT...AND MAINLY 30S ELSEWHERE
OVER THE W-CNTRL MOHAWK VALLEY...ERN CATSKILLS...SRN DACKS
REGION...LAKE GEORGE REGION...THE SRN GREENS AND BERKSHIRES. THERE
SHOULD BE ENOUGH WIND TO PRECLUDE ANY FROST ISSUES THURSDAY MORNING
WHERE THE GROWING SEASON HAS BEGIN. HIGHS ON THU WITH THE SFC HIGH
BUILDING IN FROM THE GREAT LAKES REGION WILL BE INN THE LOWER TO MID
60S IN THE VALLEYS...AND 50S OVER THE HIGHER TERRAIN. THE SFC HIGH
SHOULD HAVE PLENTY OF SUBSIDENCE WITH IT FOR MOSTLY SUNNY
CONDITIONS.
THU NIGHT INTO FRIDAY...THE SFC ANTICYCLONE BUILDS IN OVER THE
NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS.
THIS WILL LIKELY BE THE COLDEST NIGHT WITH TEMPS IN THE U30S TO L40S
IN THE VALLEY AREAS...AND LOWER TO M30S OVER THE HIGHER TERRAIN.
SOME FROST ISSUES MAY ARISE IN A FEW SPOTS WHERE THE GROWING SEASON
HAS BEGIN. BY FRIDAY AFTERNOON...THE SFC HIGH MOVES OFF THE THE MID
ATLANTIC COAST...AND MID LEVEL HEIGHTS INCREASE OVER THE NORTHEAST.
ANOTHER NICE DAY IS EXPECTED WITH TEMPS NUDGING SLIGHTLY ABOVE
NORMAL WITH HIGHS IN THE U60S TO L70S IN THE VALLEY AREAS...AND
LOWER TO M60S OVER THE MTNS.
FRI NIGHT INTO SATURDAY...THE FAIR WEATHER LOOKS TO CONTINUE INTO
THE FIRST PART OF THE WEEKEND WITH THE MID-LEVEL RIDGE AXIS OVER NY
AND NEW ENGLAND. A WEAK SYSTEM TRIES TO APPROACH FROM THE TN AND OH
VALLEYS. MOST OF THE GUIDANCE KEEPS IT SOUTH AND WEST OF THE ALY
FCST AREA. A SLIGHT CHC OF SHOWERS WAS ADDED TO THE ERN
CATSKILLS/WRN MOHAWK VALLEY SAT PM...BUT OVERALL DRY WEATHER IS
EXPECTED TO START THE WEEKEND WITH TEMPS SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL BECOME STATIONARY NORTH OF THE ST LAWRENCE RIVER
VALLEY TONIGHT WITH WEAK DISTURBANCES MOVING ALONG IT. THE FRONT
WILL SLOWLY BEGIN TO SAG SOUTH TOMORROW WITH INCREASED CHANCES OF
SHOWERS AND THUNDERSTORMS ESPECIALLY NORTH OF THE MOHAWK RIVER
VALLEY.
THE FORECAST AREA WILL REMAIN IN A WARM SECTOR TONIGHT. IT WILL BE
A WARM AND HUMID AIR MASS FOR MAY...AS LOW-LEVEL MOISTURE
CONTINUES TO INCREASE IN THE BOUNDARY LAYER. THE LOW-LEVEL
SOUTHERLY FLOW WILL ALLOW LOW STRATUS TO FORM FOR
KPOU...KPSF...KGFL...AND KALB TONIGHT. THE LOW STRATUS IS EXPECTED
TO FORM BTWN 03Z-06Z WITH MVFR CONDITIONS WITH CIGS BTWN 1-1.5 KFT
AGL. EXPECT THE CIGS TO LOWER TO IFR LEVELS WITH SOME MIST AT KPOU
AND KPSF PRIOR TO OR AROUND 06Z. THE IFR CIGS AND VSBYS WILL LAST
UNTIL 12Z-15Z AT THESE SITES. IT IS TOUGH TO DISCERN IF KALB WILL
HAVE IFR CIGS DUE TO A STEADY SOUTHERLY BREEZE UP THE HUDSON RIVER
VALLEY...SO LOW MVFR CIGS WERE LEFT THERE. KGFL...THE WINDS ARE
EXPECTED TO BECOME LIGHT TO CALM...AND IFR CIGS/VSBYS HAVE BEEN
FORECASTED FROM 09Z-13Z.
THE STRATUS WILL ERODE BELOW THE LOW-LEVEL INVERSION IN THE LATE
MORNING WITH CIGS/VSBYS RISING BACK TO VFR LEVELS DUE TO SOME
SUNSHINE AND MIXING. HOWEVER...MID CLOUDS WILL INCREASE AND THE
THREAT FOR SOME SCT SHOWERS AND THUNDERSTORMS WELL IN ADVANCE OF
THE COLD FRONT. VCSH GROUPS WERE ADDED TO KGFL/KALB/KPSF BTWN
18Z-21Z. OUR CONFIDENCE WAS NOT GREAT ENOUGH TO ADD THUNDER TO THE
TAF SITES YET.
THE WINDS WILL BE FROM THE SOUTH AT 5-12 KTS EARLY TONIGHT...AND
THEY WILL BECOME LIGHT TO CALM AT KPSF/KGFL/KPOU...BUT DUE TO THE
CHANNELING UP THE HUDSON RIVER VALLEY EXPECT SOUTHERLY WINDS OF
AROUND 10 KTS AT KALB THROUGHOUT THE NIGHT. THE WINDS WILL BE FROM
THE SOUTH TO SOUTHWEST TOMORROW AT 8-12 KTS WITH SOME GUSTS AROUND
20 KTS AT KALB.
OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
HAVE ISSUED A SPS FOR BERKSHIRE AND LITCHFIELD COUNTIES FOR
ELEVATED FIRE WEATHER POTENTIAL FOR SUNDAY.
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT
LAKES...WILL APPROACH OUR REGION THROUGH SUNDAY AND MAY STALL
ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS
CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY
INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT
NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND
TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH
INCREASING HUMIDITY LEVELS.
RELATIVE HUMIDITIES WILL RISE TO 80 TO 100 PERCENT TONIGHT...FALL
TO 35 TO 55 PERCENT ON SUNDAY...RISE TO 85 TO 100 PERCENT ON
SUNDAY NIGHT AND FALL TO 45 TO 65 PERCENT ON MONDAY.
WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TONIGHT AND
SUNDAY...SOUTH 5 TO 10 MPH SUNDAY NIGHT AND SOUTH AROUND 5 MPH ON
MONDAY.
&&
.HYDROLOGY...
DRY WEATHER LOOKS TO PERSIST THROUGH MUCH OF TONIGHT...WITH
GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
SPREADING SOUTH AND EAST FROM SUNDAY THROUGH EARLY NEXT WEEK AS A
LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY
MOVE THROUGH.
IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS.
THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH
THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST
PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/JPV
NEAR TERM...WASULA
SHORT TERM...11
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/11/JPV
AREA FORECAST DISCUSSION
NWS TAUNTON MA
300 PM EDT FRI MAY 8 2015
.SYNOPSIS...
THE WEEKEND WILL FEATURE ABOVE NORMAL TEMPERATURES...ESPECIALLY
ON SUNDAY WITH MAINLY DRY WEATHER. AN APPROACHING COLD FRONT LOOKS
TO BRING A ROUND OR TWO OF SCATTERED SHOWERS AND THUNDERSTORMS
EARLY NEXT WEEK. SUBTROPICAL STORM ANA SHOULD PASS SOUTH OF THE
REGION DURING TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
BACKDOOR FRONT HAS MOVED INTO NE CT AND THE CT VALLEY IN N MA AS
OF 3 PM. TEMPS COOLING INTO THE 60S AND LOWER 70S TO THE EAST OF
THE FRONT AND 50S ALONG E COASTAL MA. TO THE WEST OF THE FRONT
TEMPS HAVE SOARED INTO THE UPPER 80S IN THE CT VALLEY. TREMENDOUS
TEMP GRADIENT ACROSS SNE AT 3 PM WITH BVY 51 AND BDL 89!
SPC MESOANALYSIS INDICATING VERY MARGINAL INSTABILITY ACROSS
WESTERN MA/CT WITH SBCAPES LESS THAN 500 J/KG. DEWPOINTS IN THE
LOWER 50S WILL LIMIT INSTABILITY. NOTING SOME CU DEVELOPMENT IN
THIS REGION AND HRRR SUGGESTING A FEW POP UP SHOWERS IN WESTERN
NEW ENG SO WILL MAINTAIN SLIGHT CHC POPS THROUGH EARLY EVENING.
THE BACKDOOR FRONT WILL STALL ACROSS FAR W NEW ENG OR E NY
TONIGHT WITH LIGHT E FLOW BRINGING ABUNDANT LOW LEVEL MOISTURE TO
SNE WHICH WILL LEAD TO STRATUS EXPANDING NORTH AND WEST FROM THE
COAST TONIGHT ALONG WITH AREAS OF FOG. AREAS OF DENSE FOG WILL
LIKELY DEVELOP ALONG THE SE NEW ENG COAST AND HAVE ISSUED A DENSE
FOG ADVISORY ALONG AND S OF WST TO PYM. PATCHY DRIZZLE ALSO
POSSIBLE NEAR THE S COAST.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
SATURDAY...
THE MAIN UNCERTAINTY IS HOW QUICKLY STRATUS AND FOG WILL
DISSIPATE...AS BACKDOOR COLD FRONT SLOWLY MIXES OUT. EXPECT
INTERIOR LOCATIONS TO QUICKLY BREAK OUT INTO PARTIAL SUNSHINE
DURING MID/LATE MORNING...BUT THE PROCESS WILL BE SLOWER ALONG
THE S COAST AND IT MAY TAKE UNTIL THE AFTERNOON AS LOW LEVEL FLOW
TURNS SOUTHERLY. IN FACT...IT IS POSSIBLE CLOUDS LINGER ACROSS
THE ISLANDS FOR MOST OF THE DAY.
HIGH TEMPS SHOULD REACH WELL INTO THE 70S IN THE INTERIOR WITH
SOME LOWER 80S POSSIBLE CT VALLEY. TEMPS TRICKY CLOSER TO THE
COAST AND WILL DEPEND ON HOW QUICKLY LOW CLOUDS AND FOG BURN OFF.
WE ARE KEEPING HIGHS IN THE 60S ALONG THE S COAST WITH LOWER 70S
JUST INLAND FROM THE COAST.
SATURDAY NIGHT...
CONTINUED LIGHT ONSHORE FLOW AND ABUNDANT LOW LEVEL MOISTURE WILL
RESULT IN STRATUS AND AREAS OF FOG REDEVELOPING ALONG THE COAST
IN THE EVENING THEN EXPANDING INTO THE INTERIOR. FOG WILL BE MOST
PREVALENT ALONG THE S COAST. IT WILL BE A MILD NIGHT WITH MINS
DROPPING INTO THE MID AND UPPER 50S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* WILL KEEP IT MOSTLY WARM AND DRY INTO MONDAY
* MARINE STRATUS / FOG HANGING ALONG THE COAST
* SWEEPING COLD FRONT AHEAD OF WHICH ANA LIFTS NE ON TUESDAY
* COOL AND DRY FOR THE REMAINDER OF THE WEEK
DISCUSSION...
LIKE AN ODD COUPLE...ANA AND THE MID-LATITUDE TROUGH MOVE TOGETHER
BUT LOOK TO REMAIN APART IN PROXIMITY TO S NEW ENGLAND FOR THE EARLY-
WEEK FORECAST TIMEFRAME. AS ALLUDED TO YESTERDAY THE NEIGHBORING OF
THE TWO MAY RESULT IN LITTLE IN THE WAY OF OUTCOMES ACROSS OUR AREA.
JUST NOT BRINGING THE LOVE OF RAINFALL WE SO DESPERATELY NEED AS WE
ARE IN ABNORMALLY-DRY CONDITIONS. WILL GO INTO MORE DETAIL BELOW...
FORECAST CONSENSUS HAS ANA WOBBLING INTO THE CAROLINAS OVER THE WEEK-
END THEN SWEEPING NE FROM THE NC/VA BORDER OUT OVER THE 40N/70W OVER
THE EARLY-WEEK AHEAD OF THE MID-LATITUDE TROUGH. DO NOT FAVOR THE
08.12Z GFS. WITH ANA FEEL THE ATTENDANT COUNTERCLOCKWISE ROTATION
SHOULD YIELD LOCALIZED RIDGE ENHANCEMENT INTO S NEW ENGLAND. EXPECT
SUNDAY-MONDAY TO BE MOSTLY DRY AS BETTER MOISTURE/INSTABILITY/LIFT
REMAIN N OF OUR REGION ALONG A NEARLY-STATIONARY FRONTAL BOUNDARY.
CAN NOT RULE SUBSEQUENT SHOWER/THUNDERSTORM ACTIVITY TO DRIFT S INTO
N MA. CONTINUED LOW-CONFIDENCE SEVERE. PERHAPS SOME GUSTY WINDS WITH
INVERTED-V PROFILES SUGGESTED VIA BUFKIT. MAIN CONCERN IS HEAVY RAIN
WITH PWATS EXCEEDING 1.5-INCHES AND POTENTIAL SLOW-MOVING / TRAINING
ACTIVITY. MEANWHILE ALONG THE S/SE-COAST BENEATH AFORMENTIONED RIDGE
ENHANCEMENT LIKELY TO SEE CONTINUED MARINE STRATUS / FOG RESULTING
IN SOUPY-COOL CONDITIONS AT TIMES. SO BETWEEN THE POTENTIAL TO THE N
AND TO THE S...ABOVE-AVERAGE TEMPERATURES AND DRY CONDITIONS ARE
FAVORED.
BETTER CHANCES FOR WET-WEATHER ACROSS S NEW ENGLAND WILL BE AROUND
TUESDAY AS THE MID-LATITUDE TROUGH AND ATTENDANT COOL FRONT SWEEP
TO THE E AS ANA LIFTS TO THE NE OUT AHEAD. A COMBINATION OF DEEP-
LAYER MOISTURE ALONG WITH SOME WEAK INSTABILITY AND SHEAR WITHIN
THE WARM- SECTOR LOOK TO BE PRESENT. BUT WHETHER THERE IS ENOUGH
FORCING OR RATHER IF MARINE STRATUS / FOG TURNS OUT TO BE A CRUX
THERE IS JUST NO CERTAINTY. LATELY THERE HAS BEEN CONSISTENCY IN
THAT LITTLE IF ANY OUTCOMES ARISE AS S NEW ENGLAND FINDS ITSELF
BETWEEN TWO AREAS OF LIFT SUBSEQUENTLY RESULTING IN SINKING
MOTIONS AS INFERRED PER BUFKIT PROFILES. A WOBBLE OR SHIFT IN THE
FORECAST IS PLAUSIBLE SO WILL KEEP WITH CHANCE POPS. THINKING ANY
OUTCOMES WILL BE MOSTLY SHOWERY. NOT EVEN CERTAIN OF CONVECTIVE
THREATS ESPECIALLY IF COOL- FRONTAL PASSAGE IS DURING THE MORNING
PERIOD AS SUGGESTED PER THE CONSENSUS FORECAST. FAVOR THE 08.0Z
ECMWF WITH THIS FORECAST.
ENSEMBLE AND DETERMINISTIC FORECAST TRENDS IN AGREEMENT FOR THE LATE-
WEEK PERIOD. COOLER AIRMASS SETTLES ACROSS THE REGION USHERED BY NW-
FLOW. SEASONABLE CONDITIONS BENEATH HIGH PRESSURE WITH SOME CONCERN
OF FROST FOR THURSDAY AND FRIDAY MORNING. BY WEEKEND HIGH PRESSURE
SETTLES E ALONG THE W-PERIPHERY OF WHICH SW-FLOW WOULD LIKELY ADVECT
WARM-MOIST CONDITIONS BACK NORTHWARD. HOW LONG THE WARM-DRY WEATHER
WILL LAST IS UNDER SOME SCRUTINY. ANOTHER WET-WEATHER DISTURBANCE IS
POSSIBLE AS QUICKLY AS THE WEEKEND...THOUGH ENSEMBLES SIGNAL AT AN
IMPACT OVER THE EARLY-WEEK PERIOD THE FOLLOWING WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH FRIDAY/...
THROUGH 00Z...MAINLY VFR...BUT SOME IFR STRATUS MAY MOVE BACK
ACROSS THE ISLANDS AND POSSIBLY S COAST TOWARD 00Z. SOME MVFR CIGS
ACROSS NE COASTAL MA.
TONIGHT...MODERATE CONFIDENCE. WIDESPREAD IFR/LIFR DEVELOPING
DURING THE EVENING AS STRATUS AND FOG EXPAND NORTH AND WEST FROM
THE COAST. FOG WILL BE MOSTLY CONFINED TO COASTAL PLAIN WITH
AREAS OF DENSE FOG ALONG THE SE NEW ENG COAST. PATCHY DRIZZLE
POSSIBLE. TIMING OF LOWER CIGS UNCERTAIN FURTHER INLAND BUT DO
EXPECT CIGS TO EVENTUALLY LOWER TO IFR AFTER MIDNIGHT IN THE
DISTANT INTERIOR.
SATURDAY...MODERATE CONFIDENCE. IFR/LIFR STRATUS AND FOG WILL
BURN OFF DURING THE MORNING IN THE INTERIOR...BUT IT MAY TAKE
UNTIL THE AFTERNOON ALONG THE S COAST. TIMING OF IMPROVING
CONDITIONS UNCERTAIN AND PARTS OF THE S COAST AND ESPECIALLY THE
ISLANDS MAY NOT COMPLETELY CLEAR WITH ONSHORE FLOW.
SATURDAY NIGHT...MODERATE CONFIDENCE. IFR/LIFR STRATUS AND FOG
REDEVELOPING ALONG THE COAST AND EXPANDING INLAND ACROSS SNE
WITH LOCALLY DENSE FOG NEAR THE S COAST.
KBOS TAF...MODERATE CONFIDENCE IN TAF. EXACT TIMING UNCERTAIN. EXPECT
IFR CIGS/VSBYS DEVELOPING TONIGHT WITH LIFR POSSIBLE.
KBDL TAF...MODERATE CONFIDENCE IN TAF. A PERIOD OF IFR CIGS
POSSIBLE LATE TONIGHT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY INTO MONDAY...MODERATE CONFIDENCE.
VFR. BREEZY SW-FLOW. IFR-LIFR MARINE STRATUS / FOG ALONG S/SE-
SHORELINE TERMINALS...ENCROACHING INTO THE INTERIOR DURING THE
OVERNIGHT INTO MORNING PERIODS. -DZ POSSIBLE WITH STRATUS / FOG.
LOW CONFIDENCE -SHRA / TSRA OVER N MA FOR THE PERIOD.
TUESDAY...LOW CONFIDENCE.
SWEEPING COOL FRONT AHEAD OF WHICH ANA LIFTS NE. MIX OF LOW-END VFR
DOWN TO IFR CIGS. LOWEST CONDITIONS EXPECTED ALONG COAST. BREEZY SW-
WINDS. SCT -SHRA EXPECTED. LOW CONFIDENCE TSRA.
WEDNESDAY...MODERATE CONFIDENCE.
IMPROVING. VFR. NW-WINDS POTENTIALLY GUSTY UP TO 20 KTS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.
THROUGH TONIGHT...A FEW N/NE GUSTS NEAR 25 KT WILL PERSIST THIS
AFTERNOON BEFORE DIMINISHING BY EARLY EVENING. 5 FT SEAS NE MA
COASTAL WATERS WILL SUBSIDE THIS EVENING. OTHERWISE...EXPECT WINDS
TO DIMINISH AND BECOME LIGHT EASTERLY WITH SEAS BELOW SCA.
AREAS OF DENSE FOG DEVELOPING WILL RESULT IN POOR VSBYS.
SATURDAY...WINDS TURN SOUTHERLY AND INCREASE DURING THE AFTERNOON
BUT REMAINING BELOW SCA. AREAS OF DENSE FOG IN THE MORNING WITH
IMPROVEMENT IN VSBYS DURING THE AFTERNOON.
SATURDAY NIGHT...MAINLY SW WINDS 15 KT OR LESS WITH SEAS BELOW
SCA. AREAS OF DENSE FOG REDEVELOPING.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY INTO MONDAY...MODERATE CONFIDENCE.
BREEZY S/SW-FLOW BUT REMAINING BELOW SMALL-CRAFT ADVISORY CRITERIA.
GUSTS UP TO 20 KTS WITH THE POSSIBILITY OF WAVES BUILDING UP TO 5-
FEET ON THE OUTER WATERS. LIKELY MARINE STRATUS / FOG AHEAD OF ANA.
LOW VISIBILITIES ON THE WATERS AT TIMES MIXED IN WITH DRIZZLE.
TUESDAY...LOW CONFIDENCE.
APPROACHING COOL FRONT AHEAD OF WHICH ANA LIFTS NE ACROSS 40N/70W.
SCATTERED SHOWERS...LOW CONFIDENCE ON THUNDERSTORMS. INCREASING SW-
WINDS AHEAD OF THE COLD FRONT COULD GUST IN EXCESS OF 25 KTS. ALONG
WITH SWELL FROM ANA...COULD BE LOOKING AT SEAS OF 6-8 FEET ON THE S
AND SE WATERS EXPOSED TO THE ATLANTIC.
WEDNESDAY...MODERATE CONFIDENCE.
CONDITIONS IMPROVING AS ANA MOVES E. SWELL DIMINISHING SLOWLY UNDER
BREEZY NW-WINDS WITH GUSTS UP TO 20 KTS. WAVE HEIGHTS DROPPING BELOW
5-FEET ON THE S/SE-OUTER WATERS BY THURSDAY MORNING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003.
MA...DENSE FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM EDT
SATURDAY FOR MAZ018>024.
RI...DENSE FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM EDT
SATURDAY FOR RIZ006>008.
MARINE...NONE.
&&
$$
SYNOPSIS...KJC/SIPPRELL
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
156 PM EDT FRI MAY 8 2015
.SYNOPSIS...
A STRONG BACKDOOR COLD FRONT WILL BRING MUCH COOLER TEMPERATURES TO
THE EASTERN MASSACHUSETTS COAST THIS AFTERNOON...WHILE IT REMAINS
VERY WARM ACROSS WESTERN NEW ENGLAND. THE WEEKEND WILL FEATURE
ABOVE NORMAL TEMPERATURES...ESPECIALLY ON SUNDAY WITH MAINLY DRY
WEATHER. AN APPROACHING COLD FRONT LOOKS TO BRING A ROUND OR TWO
OF SCATTERED SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.
SUBTROPICAL STORM ANA SHOULD PASS SOUTH OF THE REGION DURING
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
145 PM UPDATE...
BACKDOOR FRONT HAS MOVED WEST TO CENTRAL MA AND RI WITH TEMPS
COOLING INTO THE 60S TO THE WEST AND 50S ALONG E COASTAL MA. TO
THE WEST OF THE FRONT TEMPS HAVE SOARED INTO THE MID 80S IN THE
CT VALLEY. WITH THE FRONT NOT REACHING CT VALLEY UNTIL LATE
AFTERNOON WILL LIKELY SEE SOME UPPER 80S IN THE CT VALLEY.
AREAS OF STRATUS AND PATCHY FOG LINGERING ACROSS THE S COASTAL
WATERS MAY FILL BACK IN ACROSS THE ISLANDS BY LATE AFTERNOON.
SPC MESOANALYSIS INDICATING VERY MARGINAL INSTABILITY ACROSS
WESTERN MA/CT WITH SBCAPES LESS THAN 500 J/KG. DEWPOINTS IN THE
LOW TO MID 50S WILL LIMIT INSTABILITY. NOTING SOME CU
DEVELOPMENT IN THIS REGION AND HRRR SUGGESTING A FEW POP UP
SHOWERS IN WESTERN NEW ENG SO WILL MAINTAIN SLIGHT CHC POPS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
THE BACKDOOR COLD FRONT WILL LOSE ITS PUNCH AS IT MOVES INTO WESTERN
NEW ENGLAND. HOWEVER...INCREASING LOW LEVEL MOISTURE WILL LEAD TO
THE DEVELOPMENT OF LOW CLOUDS AND AREAS OF FOG. SOME OF THE FOG MAY
END UP LOCALLY DENSE...ESPECIALLY ALONG THE SOUTHEAST COAST WHERE
THERE MAY BE SOME DRIZZLE. LATER SHIFTS MAY HAVE TO CONSIDER A
DENSE FOG ADVISORY FOR PORTIONS OF THE REGION. LOW TEMPS WILL
MAINLY BE IN THE UPPER 40S AND LOWER 50S.
SATURDAY...
THE MAIN UNCERTAINTY ON SATURDAY IS HOW QUICKLY STRATUS AND FOG WILL
DISSIPATE...AS BACKDOOR COLD FRONT CONTINUES TO WEAKEN AND SLOWLY
WASH OUT. HOWEVER..GIVEN LIGHT ONSHORE FLOW...WOULD NOT BE
SURPRISED IF LOW CLOUDS/FOG LASTED A BIT LONGER THEN THE MODELS
SUGGEST. STILL SHOULD SEE PARTIAL SUNSHINE EMERGE FOR MUCH OF THE
REGION BY AFTERNOON...ALTHOUGH LOW CLOUDS AND FOG PATCHES MAY LINGER
ACROSS PORTIONS OF THE COAST.
HIGH TEMPS ON SATURDAY ARE TRICKY AND WILL DEPEND ON HOW QUICKLY LOW
CLOUDS AND FOG BURN OFF. RIGHT NOW WE WILL STICK WITH HIGHS MAINLY
IN THE 70S...BUT PROBABLY ONLY 65 TO 70 ALONG THE IMMEDIATE COAST.
ITS POSSIBLE A FEW LOCATIONS IN OUR WESTERN AND NORTHERN ZONES REACH
80...IF CLOUDS BREAK UP EARLY ENOUGH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...
* WARM AND DRY CONDITIONS THROUGH REMAINDER OF THE WEEKEND
* NIGHTTIME LOW CLOUDS AND FOG ALONG S AND SE COASTAL AREAS
* REMNANTS OF SUBTROPICAL STORM ANA PASS S OF REGION AS COLD
FRONT SWEEPS IN AROUND TUESDAY
* COOLER AND DRIER CONDITIONS FOR WEDNESDAY AND THURSDAY
DISCUSSION...
MEDIUM RANGE MODELS AND ENSEMBLES IN PRETTY GOOD AGREEMENT WITH
TIMING OF SURFACE FEATURES ON THIS MORNING/S PACKAGE.
NHC HAS UPGRADED LOW PRES OFF THE SE U.S. COAST...CLASSIFYING IT
AS SUBTROPICAL STORM ANA LATE THURSDAY NIGHT. THERE IS A LOW
CHANCE THAT THE REMNANTS OF THIS SYSTEMS MAY AFFECT SOUTH COASTAL
AREAS DURING TUESDAY...BUT MODELS CONTINUE TO PUSH LOW PRES AND
COLD FRONT E WHICH SHOULD KEEP MOST OF THE SYSTEM/S EFFECTS
OFFSHORE. HAVE MENTIONED POSSIBILITY OF GUSTY E-NE WINDS...BRIEF
HEAVY SHOWERS AND HIGHER SEAS POSSIBLE IN THE HAZARDOUS WEATHER
OUTLOOK FOR OUR SOUTH COASTAL AREAS AS WELL AS THE SOUTHERN
WATERS.
RIDGING CONTINUES INTO MONDAY...SO EXPECT GENERALLY DRY
CONDITIONS. HOWEVER...WITH PERSISTENT S-SW WINDS IN PLACE...
EXPECT DEWPTS TO RISE THROUGH THE WEEKEND. WILL SEE LATE
NIGHT/EARLY MORNING LOW CLOUDS AND FOG ALONG S COASTAL AREAS SAT
NIGHT. BY SUNDAY NIGHT...FORECASTED DEWPTS WILL BE IN THE LOWER-
MID 60S...WHICH SHOULD ALLOW PATCHY LOW CLOUDS AND FOG ACROSS
MOST AREAS GENERALLY S OF THE MASS PIKE AGAIN DURING LATE NIGHT
INTO MID MORNING HOURS ON SUNDAY.
LEANED TOWARD SLOWER TIMING OF GGEM/ECMWF WHICH SLOWED PROGRESSION
OF THE FRONT A BIT MORE...THOUGH STILL COULD SEE SOME PRECIP MOVE
INTO NORTHERN MASSACHUSETTS SUNDAY NIGHT. ALSO NOTING SOME
INSTABILITY WORKING IN WITH K INDICES INTO THE LOWER 30S...WHICH
LOOKS TO WORK THROUGH TO NEAR THE MASS PIKE DURING MONDAY.
MENTIONED CHANCE FOR SHOWERS ALONG WITH A FEW THUNDERSTORMS DURING
THE AFTERNOON/EVENING HOURS. WILL BE RATHER WARM ON MOTHER/S DAY
WITH HIGHS MAINLY IN THE LOWER-MID 80S.
RATHER GOOD AGREEMENT FOR TIMING OF COLD FRONT OUT OF NY STATE
DURING TUESDAY...WITH ANOTHER ROUND OF SCT SHOWERS/TSTMS. WITH
INCREASED PWAT/S /ON ORDER OF 1.75 INCHES/...MAY SEE SOME BRIEF
HEAVY DOWNPOURS IN SOME OF THE CONVECTION THAT LOOKS TO DEVELOP
TUE AFTERNOON/EVENING.
FRONT PUSHES OFFSHORE TUE NIGHT...BRINGING IN COOLER AIR ON W-NW
WINDS. NOTING H5 S/W MOVES ACROSS DURING WED...BUT LITTLE MOISTURE
TO WORK WITH AND MOST OF THE ENERGY REMAINS N OF THE REGION SO
SHOULD BE A DRY DAY AS STRONG SURFACE HIGH WORKS IN OUT OF THE
GREAT LAKES FOR WED-THU. EXPECT GENERALLY PARTLY TO MOSTLY SUNNY
CONDITIONS WITH HIGHS CLOSE TO SEASONAL NORMALS...THOUGH MIGHT BE
A LITTLE COOLER THAN NORMAL ON THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH FRIDAY/...
THROUGH 00Z...MAINLY VFR...BUT SOME IFR STRATUS MAY MOVE BACK
ACROSS THE ISLANDS AND POSSIBLY S COAST TOWARD 00Z. SOME MVFR CIGS
ACROSS NE COASTAL MA.
TONIGHT...MODERATE CONFIDENCE. WIDESPREAD IFR/LIFR DEVELOPING
DURING THE EVENING AS STRATUS AND FOG EXPAND NORTH AND WEST FROM
THE COAST. FOG WILL BE MOSTLY CONFINED TO COASTAL PLAIN WITH
AREAS OF DENSE FOG ALONG THE SE NEW ENG COAST. PATCHY DRIZZLE
POSSIBLE. TIMING OF LOWER CIGS UNCERTAIN FURTHER INLAND BUT DO
EXPECT CIGS TO EVENTUALLY LOWER TO IFR AFTER MIDNIGHT IN THE
DISTANT INTERIOR.
SATURDAY...MODERATE CONFIDENCE. IFR/LIFR STRATUS AND FOG WILL
BURN OFF DURING THE MORNING IN THE INTERIOR...BUT IT MAY TAKE
UNTIL THE AFTERNOON ALONG THE S COAST. TIMING OF IMPROVING
CONDITIONS UNCERTAIN AND PARTS OF THE S COAST AND ESPECIALLY THE
ISLANDS MAY NOT COMPLETELY CLEAR WITH ONSHORE FLOW.
SATURDAY NIGHT...MODERATE CONFIDENCE. IFR/LIFR STRATUS AND FOG
REDEVELOPING ALONG THE COAST AND EXPANDING INLAND ACROSS SNE
WITH LOCALLY DENSE FOG NEAR THE S COAST.
KBOS TAF...MODERATE CONFIDENCE IN TAF. EXACT TIMING UNCERTAIN. EXPECT
IFR CIGS/VSBYS DEVELOPING TONIGHT WITH LIFR POSSIBLE.
KBDL TAF...MODERATE CONFIDENCE IN TAF. A PERIOD OF IFR CIGS
POSSIBLE LATE TONIGHT.
OUTLOOK...SUNDAY THROUGH TUESDAY...
SATURDAY NIGHT AND SUNDAY...MODERATE CONFIDENCE.
VFR. S-SW WINDS GUSTING TO AROUND 20 KT AT TIMES MAINLY THROUGH
MIDNIGHT SAT NIGHT ACROSS EASTERN AREAS. IFR-LIFR IN LOW
CLOUDS...FOG AND PATCHY DRIZZLE ALONG S/SE SHORELINE
TERMINALS...ENCROACHING INTO THE INTERIOR DURING THE OVERNIGHT
INTO MORNING PERIODS.
MONDAY INTO TUESDAY...LOW CONFIDENCE.
MAINLY LOW END VFR CONDITIONS...BUT MAY SEE MVFR-IFR CIGS/VSBYS IN
SCT SHOWERS. LOWEST CONDITIONS SEEN ALONG COASTAL TERMINALS. LOW
CHANCE OF TSTMS. SW WINDS GUSTING TO AROUND 20 KT ALONG S COAST
DURING TUESDAY AS REMNANTS OF SUBTROPICAL STORM ANA PASSES S OF
THE REGION.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH SATURDAY/...
TODAY...HIGH CONFIDENCE. STRONG BACKDOOR COLD FRONT SWEEPS ACROSS
OUR NORTHEAST WATERS THIS MORNING. DECENT PRESSURE RISES BEHIND THE
FRONT SHOULD YIELD A BRIEF PERIOD OF 20 TO 25 KNOT NORTHEAST WIND
GUSTS INTO MID AFTERNOON FROM BOSTON HARBOR AND POINTS NORTHEAST.
WILL GO AHEAD AND CONTINUE TO MARINE WEATHER STATEMENT FOR ANY EARLY
SEASON RECREATIONAL BOATERS. SEAS MAY REACH 5 FEET FOR A SHORT TIME
TOWARD EVENING ACROSS OUR FAR NORTHEAST WATERS...BUT FEEL ITS SHORT
LIVED AND WE ARE COVERED WITH THE MARINE WEATHER STATEMENT.
TONIGHT AND SATURDAY...HIGH CONFIDENCE. BACKDOOR COLD FRONT BEGINS
TO LOSE ITS PUNCH TONIGHT AND WILL WASHOUT BY SATURDAY. MAY SEE
SOME LEFT OVER MARGINAL 5 FOOT SEAS ACROSS OUR FAR NORTHEAST WATERS
THIS EVENING. OTHERWISE...WINDS/SEAS SHOULD REMAIN BELOW SMALL
CRAFT ADVISORY THRESHOLDS TONIGHT AND SATURDAY. HOWEVER...MAIN
CONCERN FOR MARINERS WILL BE FOR AREAS OF DENSE FOG DEVELOPING
TONIGHT AND CONTINUING INTO SATURDAY MORNING. SHOULD SEE
VISIBILITIES IMPROVE BY SATURDAY AFTERNOON FOR MUCH OF OUR
WATERS....BUT MAY LINGER ALONG THE SOUTH COAST.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT THROUGH SUNDAY NIGHT...MODERATE CONFIDENCE.
S-SW WINDS WILL REMAIN BELOW SMALL CRAFT CRITERIA...THOUGH MAY SEE
SOME GUSTS UP TO 25 KT AND SEAS UP TO 5 FT ON THE EASTERN OUTER
WATERS FOR A TIME SUNDAY NIGHT. PERIODS OF LOW CLOUDS AND FOG WILL
LIKELY REDUCE VSBYS. MAY SEE PERIODS OF DRIZZLE ALONG THE SOUTH
COASTAL WATERS SATURDAY NIGHT INTO EARLY SUNDAY MORNING.
MONDAY AND TUESDAY...LOW CONFIDENCE.
S-SW WINDS CONTINUE AS SLOW MOVING COLD FRONT APPROACHES. SOME
QUESTION AS TO WHETHER REMNANTS OF SUBTROPICAL STORM ANA AFFECT
THE SOUTHERN WATERS WITH GUSTY WINDS AND BRIEF HEAVY RAINFALL.
BEST CHANCE FOR PRECIP WILL BE TUESDAY...ALONG WITH LOW CHANCE OF
SCT THUNDERSTORMS AHEAD OF THE COLD FRONT. WINDS GUSTING UP TO 20
KT.
&&
.FIRE WEATHER...
TODAY...MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL BE DROPPING TO
NEAR 30 PERCENT WHEN HIGH TEMPS ARE REACHED AWAY FROM THE
COAST...BUT WINDS SHOULD BE LIGHT AT THAT TIME. WINDS WILL INCREASE
SOME FROM THE EAST NORTHEAST ACROSS EASTERN MA/RI BEHIND A BACKDOOR
COLD FRONT LATER THIS MORNING AND AFTERNOON. IN FACT... BRIEF EAST
TO NORTHEAST WIND GUSTS OF 20 TO 25 MPH ARE POSSIBLE IMMEDIATELY
BEHIND THE FRONT ACROSS NORTHEAST MA...BUT RELATIVE HUMIDITY VALUES
WILL BE INCREASING TO OVER 50 PERCENT AS MARINE AIR INVADES EASTERN
NEW ENGLAND.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...KJC
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...KJC/EVT
MARINE...FRANK/EVT
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
935 AM EDT FRI MAY 8 2015
.SYNOPSIS...
A STRONG BACKDOOR COLD FRONT WILL BRING MUCH COOLER TEMPERATURES TO
THE EASTERN MASSACHUSETTS COAST THIS AFTERNOON...WHILE IT REMAINS
VERY WARM ACROSS WESTERN NEW ENGLAND. THE WEEKEND WILL FEATURE
ABOVE NORMAL TEMPERATURES...ESPECIALLY ON SUNDAY WITH MAINLY DRY
WEATHER. AN APPROACHING COLD FRONT LOOKS TO BRING A ROUND OR TWO
OF SCATTERED SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.
SUBTROPICAL STORM ANA SHOULD PASS SOUTH OF THE REGION DURING
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM UPDATE...
***STRONG BACKDOOR COLD FRONT WILL RESULT IN AFTERNOON
TEMPERATURES FALLING INTO THE 50S ACROSS THE EASTERN MA COAST
WITH MIDDLE TO UPPER 80S IN THE CT RIVER VALLEY***
BACKDOOR FRONT PUSHING S ALONG THE NE MA COAST THIS MORNING AND
HAS MOVED THROUGH BOS. TEMPS FALLING SHARPLY INTO THE 50S BEHIND
THE FRONT WITH BVY DOWN TO 54. HRRR HAS FRONT REACHING ORH-PVD
16-17Z AND MAY SEE TEMPS SPIKE INTO THE LOWER 80S ACROSS PORTIONS
OF RI AND INTERIOR SE MA BEFORE THE FROPA AND FALLING TEMPS
THROUGH THE 60S AND EVEN INTO THE 50S IN SOME LOCALES IN E MA BY
LATE AFTERNOON. DECENT PRESSURE RISES BEHIND THE FRONT WILL YIELD
A BRIEF PERIOD OF NORTHEAST WIND GUSTS OF 20 TO 25 MPH ACROSS
NORTHEAST MA.
FINALLY...FURTHER BACK INTO THE INTERIOR ACROSS WESTERN MA/NORTHERN
CT IT WILL BE A VERY WARM DAY. THE BACKDOOR COLD FRONT WILL NOT
COME THROUGH UNTIL THE MID TO LATE AFTERNOON HOURS AND IN A WEAKENED
FORM. THIS SHOULD ALLOW HIGH TEMPS TO REACH INTO THE MIDDLE TO UPPER
80S.
AREAS OF STRATUS AND PATCHY FOG LINGERING ACROSS THE S COASTAL
WATERS MAY FILL BACK IN ACROSS SOME OF THE S COAST BEACHES DURING
THE AFTERNOON.
AS FOR PRECIPITATION CHANCES...THE VAST MAJORITY OF THE DAY WILL
BE DRY IN A GIVEN LOCATION. HOWEVER...BACKDOOR COLD FRONT WILL
COMBINED WITH ENOUGH INSTABILITY FOR A FEW SPOT SHOWERS AND
PERHAPS EVEN AN ISOLATED THUNDERSTORM ACROSS WESTERN MA/NORTHERN
CT. HRRR INDICATING A FEW SHOWERS LATER THIS AFTERNOON. HIGHEST
RISK FOR THIS IS ACROSS THE EAST SLOPES OF THE BERKSHIRES...WHERE
THE BETTER INSTABILITY WILL RESIDE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
THE BACKDOOR COLD FRONT WILL LOSE ITS PUNCH AS IT MOVES INTO WESTERN
NEW ENGLAND. HOWEVER...INCREASING LOW LEVEL MOISTURE WILL LEAD TO
THE DEVELOPMENT OF LOW CLOUDS AND AREAS OF FOG. SOME OF THE FOG MAY
END UP LOCALLY DENSE...ESPECIALLY ALONG THE SOUTHEAST COAST WHERE
THERE MAY BE SOME DRIZZLE. LATER SHIFTS MAY HAVE TO CONSIDER A
DENSE FOG ADVISORY FOR PORTIONS OF THE REGION. LOW TEMPS WILL
MAINLY BE IN THE UPPER 40S AND LOWER 50S.
SATURDAY...
THE MAIN UNCERTAINTY ON SATURDAY IS HOW QUICKLY STRATUS AND FOG WILL
DISSIPATE...AS BACKDOOR COLD FRONT CONTINUES TO WEAKEN AND SLOWLY
WASH OUT. HOWEVER..GIVEN LIGHT ONSHORE FLOW...WOULD NOT BE
SURPRISED IF LOW CLOUDS/FOG LASTED A BIT LONGER THEN THE MODELS
SUGGEST. STILL SHOULD SEE PARTIAL SUNSHINE EMERGE FOR MUCH OF THE
REGION BY AFTERNOON...ALTHOUGH LOW CLOUDS AND FOG PATCHES MAY LINGER
ACROSS PORTIONS OF THE COAST.
HIGH TEMPS ON SATURDAY ARE TRICKY AND WILL DEPEND ON HOW QUICKLY LOW
CLOUDS AND FOG BURN OFF. RIGHT NOW WE WILL STICK WITH HIGHS MAINLY
IN THE 70S...BUT PROBABLY ONLY 65 TO 70 ALONG THE IMMEDIATE COAST.
ITS POSSIBLE A FEW LOCATIONS IN OUR WESTERN AND NORTHERN ZONES REACH
80...IF CLOUDS BREAK UP EARLY ENOUGH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...
* WARM AND DRY CONDITIONS THROUGH REMAINDER OF THE WEEKEND
* NIGHTTIME LOW CLOUDS AND FOG ALONG S AND SE COASTAL AREAS
* REMNANTS OF SUBTROPICAL STORM ANA PASS S OF REGION AS COLD
FRONT SWEEPS IN AROUND TUESDAY
* COOLER AND DRIER CONDITIONS FOR WEDNESDAY AND THURSDAY
DISCUSSION...
MEDIUM RANGE MODELS AND ENSEMBLES IN PRETTY GOOD AGREEMENT WITH
TIMING OF SURFACE FEATURES ON THIS MORNING/S PACKAGE.
NHC HAS UPGRADED LOW PRES OFF THE SE U.S. COAST...CLASSIFYING IT
AS SUBTROPICAL STORM ANA LATE THURSDAY NIGHT. THERE IS A LOW
CHANCE THAT THE REMNANTS OF THIS SYSTEMS MAY AFFECT SOUTH COASTAL
AREAS DURING TUESDAY...BUT MODELS CONTINUE TO PUSH LOW PRES AND
COLD FRONT E WHICH SHOULD KEEP MOST OF THE SYSTEM/S EFFECTS
OFFSHORE. HAVE MENTIONED POSSIBILITY OF GUSTY E-NE WINDS...BRIEF
HEAVY SHOWERS AND HIGHER SEAS POSSIBLE IN THE HAZARDOUS WEATHER
OUTLOOK FOR OUR SOUTH COASTAL AREAS AS WELL AS THE SOUTHERN
WATERS.
RIDGING CONTINUES INTO MONDAY...SO EXPECT GENERALLY DRY
CONDITIONS. HOWEVER...WITH PERSISTENT S-SW WINDS IN PLACE...
EXPECT DEWPTS TO RISE THROUGH THE WEEKEND. WILL SEE LATE
NIGHT/EARLY MORNING LOW CLOUDS AND FOG ALONG S COASTAL AREAS SAT
NIGHT. BY SUNDAY NIGHT...FORECASTED DEWPTS WILL BE IN THE LOWER-
MID 60S...WHICH SHOULD ALLOW PATCHY LOW CLOUDS AND FOG ACROSS
MOST AREAS GENERALLY S OF THE MASS PIKE AGAIN DURING LATE NIGHT
INTO MID MORNING HOURS ON SUNDAY.
LEANED TOWARD SLOWER TIMING OF GGEM/ECMWF WHICH SLOWED PROGRESSION
OF THE FRONT A BIT MORE...THOUGH STILL COULD SEE SOME PRECIP MOVE
INTO NORTHERN MASSACHUSETTS SUNDAY NIGHT. ALSO NOTING SOME
INSTABILITY WORKING IN WITH K INDICES INTO THE LOWER 30S...WHICH
LOOKS TO WORK THROUGH TO NEAR THE MASS PIKE DURING MONDAY.
MENTIONED CHANCE FOR SHOWERS ALONG WITH A FEW THUNDERSTORMS DURING
THE AFTERNOON/EVENING HOURS. WILL BE RATHER WARM ON MOTHER/S DAY
WITH HIGHS MAINLY IN THE LOWER-MID 80S.
RATHER GOOD AGREEMENT FOR TIMING OF COLD FRONT OUT OF NY STATE
DURING TUESDAY...WITH ANOTHER ROUND OF SCT SHOWERS/TSTMS. WITH
INCREASED PWAT/S /ON ORDER OF 1.75 INCHES/...MAY SEE SOME BRIEF
HEAVY DOWNPOURS IN SOME OF THE CONVECTION THAT LOOKS TO DEVELOP
TUE AFTERNOON/EVENING.
FRONT PUSHES OFFSHORE TUE NIGHT...BRINGING IN COOLER AIR ON W-NW
WINDS. NOTING H5 S/W MOVES ACROSS DURING WED...BUT LITTLE MOISTURE
TO WORK WITH AND MOST OF THE ENERGY REMAINS N OF THE REGION SO
SHOULD BE A DRY DAY AS STRONG SURFACE HIGH WORKS IN OUT OF THE
GREAT LAKES FOR WED-THU. EXPECT GENERALLY PARTLY TO MOSTLY SUNNY
CONDITIONS WITH HIGHS CLOSE TO SEASONAL NORMALS...THOUGH MIGHT BE
A LITTLE COOLER THAN NORMAL ON THURSDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH FRIDAY/...
TODAY...HIGH CONFIDENCE.
VFR. AREAS OF IFR STRATUS ALONG THE IMMEDIATE S COAST WILL
IMPROVE TO VFR...BUT MAY LOWER BACK TO IFR BY MID/LATE AFTERNOON
AS STRATUS LIFTS BACK TO THE N. A PERIOD OF NE WIND GUSTS TO
20-25 KT ACROSS NE MA COAST. IN ADDITION...A FEW BRIEF SPOT
SHOWERS AND PERHAPS EVEN AN ISOLATED THUNDERSTORM MAY AFFECT
WESTERN MA/NORTHERN CT IN ASSOCIATION WITH THE BACKDOOR COLD FRONT
THIS AFTERNOON.
TONIGHT...MODERATE CONFIDENCE. MAINLY IFR CONDITIONS AS LOW
STRATUS AND AREAS OF FOG OVERSPREAD THE REGION FROM SOUTHEAST TO
NORTHWEST. THE FOG MAY BE LOCALLY DENSE ALONG THE SOUTHEAST NEW
ENGLAND COAST WITH AREAS OF DRIZZLE POSSIBLE.
SATURDAY...MODERATE CONFIDENCE. STRATUS AND FOG SHOULD GRADUALLY
BURN OFF SOMETIME SAT MORNING INTO THE EARLY AFTERNOON.
MODELS MAY BE A LITTLE FAST IN BREAKING UP THE LOW
CLOUDS/STRATUS GIVEN LIGHT ON SHORE FLOW...SO WE HAVE LOW
CONFIDENCE ON TIMING. ITS ALSO POSSIBLE PORTIONS OF THE SOUTH
COAST/CAPE/ISLANDS NEVER FULLY SCATTER OUT THE LOW CLOUDS/FOG
PATCHES WITH ONSHORE FLOW.
KBOS TAF...MODERATE CONFIDENCE IN TAF. BACKDOOR COLD FRONT CROSSES
TERMINAL BETWEEN 13 AND 14Z. BRIEF SURGE OF NORTHEAST WIND GUSTS OF
20 TO 25 KNOTS POSSIBLE. IFR CIGS/VSBYS DEVELOP TONIGHT.
KBDL TAF...MODERATE CONFIDENCE IN TAF. VFR TODAY WITH A SPOT
SHOWER POSSIBLE THIS AFTERNOON. MVFR TO PERHAPS IFR LOW CLOUDS/FOG
PATCHES DEVELOP LATER TONIGHT.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT AND SUNDAY...MODERATE CONFIDENCE.
VFR. S-SW WINDS GUSTING TO AROUND 20 KT AT TIMES MAINLY THROUGH
MIDNIGHT SAT NIGHT ACROSS EASTERN AREAS. IFR-LIFR IN LOW
CLOUDS...FOG AND PATCHY DRIZZLE ALONG S/SE SHORELINE
TERMINALS...ENCROACHING INTO THE INTERIOR DURING THE OVERNIGHT
INTO MORNING PERIODS.
MONDAY INTO TUESDAY...LOW CONFIDENCE.
MAINLY LOW END VFR CONDITIONS...BUT MAY SEE MVFR-IFR CIGS/VSBYS IN
SCT SHOWERS. LOWEST CONDITIONS SEEN ALONG COASTAL TERMINALS. LOW
CHANCE OF TSTMS. SW WINDS GUSTING TO AROUND 20 KT ALONG S COAST
DURING TUESDAY AS REMNANTS OF SUBTROPICAL STORM ANA PASSES S OF
THE REGION.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH SATURDAY/...
TODAY...HIGH CONFIDENCE. STRONG BACKDOOR COLD FRONT SWEEPS ACROSS
OUR NORTHEAST WATERS THIS MORNING. DECENT PRESSURE RISES BEHIND THE
FRONT SHOULD YIELD A BRIEF PERIOD OF 20 TO 25 KNOT NORTHEAST WIND
GUSTS INTO MID AFTERNOON FROM BOSTON HARBOR AND POINTS NORTHEAST.
WILL GO AHEAD AND CONTINUE TO MARINE WEATHER STATEMENT FOR ANY EARLY
SEASON RECREATIONAL BOATERS. SEAS MAY REACH 5 FEET FOR A SHORT TIME
TOWARD EVENING ACROSS OUR FAR NORTHEAST WATERS...BUT FEEL ITS SHORT
LIVED AND WE ARE COVERED WITH THE MARINE WEATHER STATEMENT.
TONIGHT AND SATURDAY...HIGH CONFIDENCE. BACKDOOR COLD FRONT BEGINS
TO LOSE ITS PUNCH TONIGHT AND WILL WASHOUT BY SATURDAY. MAY SEE
SOME LEFT OVER MARGINAL 5 FOOT SEAS ACROSS OUR FAR NORTHEAST WATERS
THIS EVENING. OTHERWISE...WINDS/SEAS SHOULD REMAIN BELOW SMALL
CRAFT ADVISORY THRESHOLDS TONIGHT AND SATURDAY. HOWEVER...MAIN
CONCERN FOR MARINERS WILL BE FOR AREAS OF DENSE FOG DEVELOPING
TONIGHT AND CONTINUING INTO SATURDAY MORNING. SHOULD SEE
VISIBILITIES IMPROVE BY SATURDAY AFTERNOON FOR MUCH OF OUR
WATERS....BUT MAY LINGER ALONG THE SOUTH COAST.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT THROUGH SUNDAY NIGHT...MODERATE CONFIDENCE.
S-SW WINDS WILL REMAIN BELOW SMALL CRAFT CRITERIA...THOUGH MAY SEE
SOME GUSTS UP TO 25 KT AND SEAS UP TO 5 FT ON THE EASTERN OUTER
WATERS FOR A TIME SUNDAY NIGHT. PERIODS OF LOW CLOUDS AND FOG WILL
LIKELY REDUCE VSBYS. MAY SEE PERIODS OF DRIZZLE ALONG THE SOUTH
COASTAL WATERS SATURDAY NIGHT INTO EARLY SUNDAY MORNING.
MONDAY AND TUESDAY...LOW CONFIDENCE.
S-SW WINDS CONTINUE AS SLOW MOVING COLD FRONT APPROACHES. SOME
QUESTION AS TO WHETHER REMNANTS OF SUBTROPICAL STORM ANA AFFECT
THE SOUTHERN WATERS WITH GUSTY WINDS AND BRIEF HEAVY RAINFALL.
BEST CHANCE FOR PRECIP WILL BE TUESDAY...ALONG WITH LOW CHANCE OF
SCT THUNDERSTORMS AHEAD OF THE COLD FRONT. WINDS GUSTING UP TO 20
KT.
&&
.FIRE WEATHER...
TODAY...MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL BE DROPPING TO
NEAR 30 PERCENT WHEN HIGH TEMPS ARE REACHED AWAY FROM THE
COAST...BUT WINDS SHOULD BE LIGHT AT THAT TIME. WINDS WILL INCREASE
SOME FROM THE EAST NORTHEAST ACROSS EASTERN MA/RI BEHIND A BACKDOOR
COLD FRONT LATER THIS MORNING AND AFTERNOON. IN FACT... BRIEF EAST
TO NORTHEAST WIND GUSTS OF 20 TO 25 MPH ARE POSSIBLE IMMEDIATELY
BEHIND THE FRONT ACROSS NORTHEAST MA...BUT RELATIVE HUMIDITY VALUES
WILL BE INCREASING TO OVER 50 PERCENT AS MARINE AIR INVADES EASTERN
NEW ENGLAND.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...KJC/FRANK
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...KJC/FRANK/EVT
MARINE...FRANK/EVT
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
332 PM EDT FRI MAY 8 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BE ACROSS THE AREA TONIGHT AND THROUGH
THE WEEKEND. SUB TROPICAL STORM ANA WILL MEANDER OFF THE CAROLINA
COASTAL AREAS THIS WEEKEND AND THEN SLOWLY MOVE NORTH WARD EARLY
NEXT WEEK. A COLD FRONT WILL CROSS OUR AREA TUESDAY. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
HEADING INTO THIS EVENING, COMPARING CURRENT HRRR AND RADAR RETURNS
(MODEL LOOKS TO BE VERIFYING LOCATION OF ENHANCED CU MORE SO THAN
PCPN IN OUR CWA) AND WHERE IT GOES FROM HERE, NO POPS IN OUR CWA.
GFS WHICH IS MORE AGGRESSIVE WITH PCPN NORTH AND WEST CWA FCST
SFC DEW POINTS ARE VERIFYING 5-8F TOO MOIST IN OUR AREA.
A PERSISTENT ONSHORE FLOW PATTERN IS EXPECTED TO CONTINUE FOR
TONIGHT (AND REALLY THROUGH THE WEEKEND). WITH DEW POINTS STILL
HIGHER THAN WATER TEMPS, CURRENT FOG OVER THE OCEAN SHOULD ONCE
AGAIN SPREAD INLAND AND BECOME DENSE AGAIN. THE HRRR WHICH DID
VERY WELL WITH THE DENSE FOG LAST NIGHT WAS HITTING NEW JERSEY
HARD WITH THE FOG AGAIN. IN DELMARVA (TU AKQ AND LWX) THE UPS
CROSSOVER PROCEDURE IS SUGGESTING MORE STRATUS THAN FOG.
THE NARRE THRU 05Z IS MORE SERN NJ AND DE CENTRIC.
LAST NIGHT IT WAS A BIT TOO CONSERVATIVE.
AS A FIRST STEP, WE ARE GOING TO ISSUE A DENSE FOG ADVISORY STARTING
NEARLY IMMEDIATELY FOR THE COAST AND THEN INCLUDING ALL OF DELAWARE
AND PRETTY MUCH EAST OF THE I295/NJ TURNPIKE CORRIDOR STARTING LATER
TONIGHT. WE WILL CARRY PATCHIER FOG FOR LOCATIONS FARTHER TO THE
NORTHWEST AND WEST AND LET THE EVENING SHIFT REASSESS. MIN
TEMPERATURES ARE A STAT GUIDANCE BLEND.
&&
.SHORT TERM /6 AM SATURDAY THROUGH 6 AM SATURDAY/...
MODEL FORECASTING SOUNDINGS ARE SUGGESTING A SLOWER BURNING OFF THE
FOG AND THE LOW CLOUDS THAN OCCURRED TODAY. EITHER WAY GIVEN THE
LENGTH OF THE DAY, THE SUN WILL GET ITS WAY AND ERODE THE CLOUDS.
MODELS HAVE BEEN FORECASTING SOME ISOLATED CONVECTION. MOST OF
IT IS PREDICATED ON PREDICTED SFC DEW POINTS THAT ARE 5-10F HIGHER
THAN THEIR OWN STAT GUIDANCE. A MORE REALISTIC MIXING OF SUB 850MB
MOISTURE WOULD HAVE THE CAP HOLD IN MOST OF OUR CWA. THE ONLY
LOCATION WHERE STAT AND SFC PREDICTED DEW POINTS COME CLOSE IS IN
DELMARVA. MESOSCALE MODELS ARE ALSO SHOWING A DOUBLE BAY BREEZE
CONVERGENCE AND WE KEPT AN ISOLATED CHANCE OF AFTERNOON THUNDER
THERE.
HIGHER GFS MOS STAT GUIDANCE LOOKS BETTER. BOTH NAM AND GFS FCST MAX
TEMPS OFF THEIR AFTN SOUNDINGS ARE MORE IN LINE WITH GFS MOS. THE
LATTER IS ALREADY TOO LOW IN NORTHWEST AREAS TODAY.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
SAT NIGHT THRU SUN NIGHT...THE WEAK RIDGE OF HIGH PRESSURE WILL
REMAIN ACROSS THE AREA. LITTLE IN THE WAY OF MEASURABLE RAINS ARE
EXPECTED...BUT SCT TSTMS ARE POSSIBLE SUN AFTERNOON. AREAS OF FOG
AND DRIZZLE ARE EXPECTED SAT NIGHT AND SUN NIGHT. TEMPERATURES WILL
REMAIN ABOVE NORMAL FOR EARLY MAY.
MON THRU TUE NIGHT...AN UNSETTLED PERIOD WITH THE MOISTURE FROM ANA
AND AN APPROACHING COLD FRONT ACTING UPON THE INCREASED LOW LEVEL
MOISTURE. SCT SHOWERS AND TSTMS FAVORING THE AFTERNOON AND EARLY
EVENING HOURS. SOME LOCALLY HEAVY RAINS ARE POSSIBLE. TEMPERATURES
STILL ABOVE NORMAL WITH HUMID CONDITIONS EXPECTED.
WED THRU FRI...FAIR WEATHER WILL RETURN BEHIND THE COLD FRONT WED.
THE FAIR WEATHER WILL CONTINUE INTO FRI. TEMPERATURES WILL DROP
BACK TO NORMAL LEVELS WED AND REMAIN NEAR NORMAL THRU FRI. THE
AIR WILL BE DRIER/MORE COMFORTABLE THAN MON/TUE.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING BEFORE DROPPING
DOWN TO IFR/LIFR TONIGHT. FOG ALONG THE COAST WILL PUSH INLAND
TONIGHT ON A CONTINUED EASTERLY FLOW. KMIV/KACY WILL BE IMPACTED BY
LOWER VISIBILITIES AND CEILINGS BY 01Z/02Z, WITH POINTS INLAND
STARTING TO SEE EFFECTS FROM THE FOG BETWEEN 05Z-08Z. THE FOG MAY BE
DENSE ENOUGH THAT WE SEE 1/4SM OR LESS AT TIMES AT SOME OF THE
TERMINALS.
THE FOG, AND SOME LOWER CEILINGS, WILL REMAIN ACROSS THE REGION INTO
SATURDAY MORNING. CLEARING WILL BE SLOW, LIKELY SLOWER THAN THIS
MORNING, AND WE WILL REMAIN SUB-VFR THROUGH MID TO LATE MORNING.
KABE/KRDG WILL CLEAR EARLIER WITH POINTS TO THE SOUTH AND EAST
TAKING LONGER TO CLEAR. CEILINGS MAY LINGER IN THE MVFR RANGE INTO
THE AFTERNOON.
OUTLOOK...
SAT NIGHT THRU SUN NIGHT...LOCALLY POOR CONDITIONS IN
FOG/DRIZZLE/LOW CLOUDS. SCT SHOWERS SUN AFTERNOON.
MON THRU TUE NIGHT...SCT SHOWERS/TSTMS WITH LOWER CONDITIONS
POSSIBLE. AREAS OF FOG NEAR THE COAST.
WED...MOSTLY VFR.
&&
.MARINE...
WE HAVE EXTENDED THE DENSE FOG ADVISORY FOR MOST OF THE AREA
WATERS THROUGH NOON ON SATURDAY, FROM MANASQUAN INLET, NJ SOUTH
TO FENWICK ISLAND, DE AND FOR SOUTHERN DELAWARE BAY. DENSE FOG IS
EXPECTED TO CONTINUE FOR THESE AREAS THROUGH MIDDAY SATURDAY BASED
ON LATEST OBSERVATIONS FROM MARINERS AND SATELLITE IMAGERY.
ELSEWHERE, FOR THE WATERS OFF THE MONMOUTH COUNTY COAST AND FOR
THE UPPER DELAWARE BAY, VISIBILITY CONDITIONS HAVE BRIEFLY
IMPROVED THIS AFTERNOON BUT ARE ANTICIPATED TO ONCE AGAIN
DETERIORATE THIS EVENING AND TONIGHT. THE DENSE FOG ADVISORY GOES
INTO EFFECT FOR THESE AREAS FROM 7PM THIS EVENING THROUGH NOON
SATURDAY.
OTHERWISE, WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA THROUGH TONIGHT.
OUTLOOK...
SAT NIGHT THRU SUN NIGHT...SUB-SCA CONDITIONS. AREAS OF DRIZZLE
AND FOG.
MON THRU TUE...LOW-END SCA CONDITIONS FOR SEAS POSSIBLE. SCT
TSTMS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...DENSE FOG ADVISORY FROM 7 PM THIS EVENING TO 11 AM EDT
SATURDAY FOR NJZ014-024>026.
DENSE FOG ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY
FOR NJZ013-016>023-027.
DE...DENSE FOG ADVISORY FROM 7 PM THIS EVENING TO 11 AM EDT
SATURDAY FOR DEZ004.
DENSE FOG ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY
FOR DEZ001>003.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL NOON EDT SATURDAY FOR ANZ431-451>455.
DENSE FOG ADVISORY FROM 7 PM THIS EVENING TO NOON EDT SATURDAY
FOR ANZ430-450.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/MEOLA
SHORT TERM...GIGI/MEOLA
LONG TERM...O`HARA
AVIATION...MEOLA/O`HARA
MARINE...GIGI/KLINE/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
202 AM EDT FRI MAY 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE REGION TONIGHT
WITH A SECONDARY AREA OF HIGH PRESSURE BUILDING ACROSS THE MID
ATLANTIC STATES ON FRIDAY. THIS FEATURE WILL BE IN PLACE THROUGH THE
WEEKEND WITH AN AREA OF LOW PRESSURE OFF THE CAROLINA COASTLINE. FOR
THE EARLY PART OF NEXT WEEK, A COLD FRONT WITH AN ASSOCIATED AREA
OF LOW PRESSURE WILL MOVE ACROSS THE CENTRAL AND EASTERN UNITED
STATES AS THE LOW OFF THE CAROLINA COASTLINE WEAKENS. HIGH
PRESSURE WILL BUILD IN BEHIND THE COLD FRONT FOR THE MIDDLE PART
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
2 AM UPDATE...DENSE FOG CONTINUES TO SPREAD INLAND SO HAVE
EXPANDED THE DENSE FOG ADVISORY TO NEW CASTLE AND SALEM COUNTIES
AS WELL AS OCEAN AND SOUTHEASTERN BURLINGTON COUNTIES. IN OCEAN
AND SOUTHEASTERN BURLINGTON COUNTIES, THE IMPACTS ARE EXACERBATEDBY
THE FACT THAT SMOKE FROM THE FOREST FIRE IN WHARTON STATE FOREST
IS ALSO CONTRIBUTING TO REDUCED VISIBILITIES. FURTHER WEST, DEW
POINT DEPRESSIONS REMAIN ABOUT 5 DEGREES F OR MORE. THIS COMBINED
WITH A SHIFT TO WEST SOUTHWESTERLY WINDS SHOULD BE ENOUGH TO
PRECLUDE DENSE FOG DEVELOPMENT, THOUGH SOME VISIBILITIES AS LOW AS
1 MILE ARE POSSIBLE.
PREVIOUS NEAR TERM DISCUSSION...WE DID SOME TEMPERATURE
ADJUSTMENTS AS THEY WERE FALLING FASTER THAN ANTICIPATED TOWARD
THE COAST. THE REST OF THE FORECAST AND HEADLINES REMAINED THE
SAME.
THE TRAFFIC CAMS ARE SHOWING THE DENSER FOG BECOMING MORE
WIDESPREAD ALONG THE COASTAL STRIP FROM ACY SOUTH, SO WE WENT
AHEAD AND ISSUED A DENSE FOG ADVISORY FOR THOSE AREAS EFFECTIVE
IMMEDIATELY.
THEN WE USED THE MORE CONSERVATIVE NARRE AS A STARTING POINT AS TO
HOW FAR WESTWARD/SOUTHWESTWARD TO ANTICIPATE DENSE FOG FORMING
OVERNIGHT. THE SPLIT IN MODELS CONTINUES WITH THE HRRR REMAINING
MORE AGGRESSIVE WITH BRINGING DENSE FOG NEARLY TO PHILADELPHIA
AND THROUGHOUT THE SOUTHERN HALF OF NEW JERSEY AND MOST OF
DELMARVA. GIVEN THE RECENT DRY WEATHER AND HOW TODAY INLAND WAS
WARMER THAN STAT GUIDANCE, NOT CONFIDENT ENOUGH TO GO THAT WAY. WE
DID EXTEND THE MENTION OF SOME PATCHY DENSE FOG TO PARTS OF THESE
AREAS NEAR THE DELAWARE BAY AND RIVER.
FAIR WEATHER TO CONTINUE OVERNIGHT WITH HIGH PRESSURE MOVING
OFFSHORE. PATCHY FOG OVERNIGHT MOST AREAS...PERHAPS NOT AS MUCH
FAR NORTH. MORE WIDESPREAD AREAS OF FOG ALONG THE SRN NJ/DELMARVA.
LOWS OVERNIGHT WILL DROP INTO THE MID/UPPER 50S MOST AREAS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/...
FAIR WEATHER WILL CONTINUE FRIDAY. THERE WILL STILL BE SOME FOG
AROUND EARLY...BUT THE SUN WILL QUICKLY BURN THINGS OFF BY AROUND 8
AM OR SO. ITS POSSIBLE THAT SOME FOG MAY LINGER ACROSS THE
COAST...LIKE TODAY. HIGH TEMPS FRI WILL RISE INT THE UPPER 70S/LOW
80S MOST AREAS...COOLER NEAR THE SHORE. WINDS SHOULD MOSTLY S OR SW
AT 5 TO 10 MPH DURING THE DAY.
&&
.LONG TERM /TONIGHT THROUGH THURSDAY/...
GOOD AGREEMENT WITH THE VARIOUS ENSEMBLE AND OPERATIONAL MODELS
WITH THE GENERAL OVERALL PATTERN IN ALL PERIODS. THE MAIN
DISCREPANCY IS THE ECMWF AND THE ECMWF NUMERICAL GUIDANCE LOOK TO
COOL IN THE THREE TO FIVE DAY, WHILE THE GFS IS PERHAPS A TAD TO
WARM. ANY TROPICAL DEVELOPMENT OF THE LOW PRESSURE SYSTEM OFF THE
CAROLINAS MAY LEAD TO HIGHER RAIN CHANCES EARLY NEXT WEEK WITH ANY
OTHER IMPACTS TO DAILY WEATHER VERY LIMITED. DETAILS BELOW...
THIS WEEKEND: WITH HIGH PRESSURE LOCATED TO OUR NORTHEAST AND A LOW
PRESSURE OFF THE CAROLINA COAST A SOUTHEASTERLY FLOW WILL BE IN
PLACE. MOISTURE WILL BE ON THE INCREASE EACH DAY ALONG WITH RISING
925 MB TEMPERATURES AS A WARMER AIRMASS IS ADVECTED INTO THE REGION.
MANY LOCATIONS ARE LIKELY TO GET INTO THE LOW/MID 80`S ON AVERAGE
AFTER STARTING OUT IN THE UPPER 50`S/LOW 60`S. THE SOUTHEAST FLOW IS
LIKELY TO KEEP TEMPERATURES ALONG THE COAST COOLER. WITH THE LIGHT
SOUTHEASTERLY FLOW SOME MORNING FOG EACH DAY COULD OCCUR. ALSO THE
INCREASED INSTABILITY AND HUMIDITY MAY LEAD TO AN ISOLATED SHOWER OR
STORM. NO TRIGGER IN THIS PERIOD FOR ANYTHING MORE THAN ISOLATED TO
PERHAPS SCATTERED SHOWERS AND STORMS, GOING SLIGHT CHANCE ATTM.
MONDAY AND TUESDAY: A COLD FRONT WILL MOVE INTO THE REGION BY
TUESDAY ALONG WITH MOISTURE INCREASING FROM A DECAYING LOW PRESSURE
SYSTEM NEAR OR NORTH OF THE CAROLINAS. THESE TWO FEATURES WILL
RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
THAT MAY PRODUCE SOME NEEDED RAINS. ENOUGH SEPARATION WITH THESE
FEATURES WILL LIMIT THE WIDESPREAD HEAVY RAIN THREAT BUT SOME
LOCALIZED DOWNPOURS ARE POSSIBLE. LOW LEVEL MOISTURE AND LIGHT
WINDS MAY RESULT IN ADDITIONAL PERIODS OF PATCHY FOG. RISING 925 MB
TEMPERATURES TO AROUND 20C SHOULD ALLOW INLAND AREAS TO RUN WELL
ABOVE CURRENT NUMERICAL GUIDANCE AND MODELED TWO METER TEMPERATURES
IN THE MID 80`S WITH OVERNIGHT LOWS EACH MORNING IN THE LOW TO MID
60`S. IN TERMS OF ANY SEVERE THREAT WITH THE FRONT, THIS LOOKS
LIMITED AS THE BEST DYNAMICS WILL BE NORTHWEST OF THE MORE
FAVORABLE INSTABILITY ATTM. AREAS THAT DO NOT SEE THE SCATTERED
STORMS WILL SLIP CLOSER TO DROUGHT CONDITIONS AS SHORT TERM DEFICITS
WITH RAINFALL CONTINUE TO GROW.
WEDNESDAY AND THURSDAY: AFTER THE COLD FRONTAL PASSAGE, HIGH
PRESSURE WILL BUILD INTO THE REGION WITH A DRIER AND COOLER AIRMASS.
GOING WITH A LARGER TEMPERATURE SPREAD THAN THE MODELED TWO METER
VALUES. CONSIDERABLE SUNSHINE MAY STILL ALLOW FOR HIGHS INTO THE
70`S AFTER CHILLIER STARTS IN THE 40`S/50`S. THE MAIN CONCERN MAY
END UP BEING FAVORABLE CONDITIONS FOR FIRE SPREAD. RH VALUES AROUND
35% EACH AFTERNOON COUPLED WITH STRONG WEST-NORTHWEST WINDS ARE
POSSIBLE.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
06Z TAFS...FOG BANK CONTINUES TO MOVE INLAND. KACY AND KMIV
ALREADY HAVE LIFR CONDITIONS, AND EXPECT SIMILAR CONDITIONS TO
DEVELOP AT KILG SOON (WHERE 400 FT AGL CEILINGS HAVE ALREADY
DEVELOPED). FOR THE REST OF THE DELAWARE VALLEY SITES (KPHL, KPNE,
AND KTTN), THE LOW STRATUS COULD REACH THOSE AIRPORTS AFTER 09Z,
BUT DEWPOINT DEPRESSIONS OF AT LEAST 5 DEGREES F SHOULD PRECLUDE
DENSE FOG FROM GETTING THAT FAR INLAND. FURTHER WEST AT KABE AND
KRDG, SOME MVFR VISIBILITES MAY DEVELOP AROUND SUNRISE, BU THE
MAIN LOW STRATUS DECK SHOULD NOT REACH THOSE SITES.
FRIDAY MORNING...ALL TERMINALS GO VFR, KACY EXPECTED TO GO LAST.
WINDS BECOME SOUTH AT AROUND 5 MPH AND CUMULUS AROUND 5000 TO
6000FT AGL MAY DEVELOP BY MID DAY.
FRIDAY AFTERNOON... SOUTH TO SOUTHEAST WINDS SHOULD BECOME
STRONGER, CLOSER TO 10 KNOTS. IT DOES NOT APPEAR THAT A SEA BREEZE
FRONT WILL FORM, MORE OF A GENERAL SYNOPTIC SCALE WIND AROUND THE
SURFACE HIGH.
OUTLOOK...
FRIDAY NIGHT THROUGH SUNDAY: VFR DURING THE DAY WITH SOUTH-
SOUTHEAST WINDS UNDER 10 KNOTS. IFR WITH FOG AND LOW STRATUS EACH
NIGH POSSIBLE. THE HIGHEST RISK FOR FOG IS AT KACY, KMIV, AND
KILG, BUT WILL BE POSSIBLE AT ALL TAF SITES.
MONDAY AND TUESDAY: VFR THROUGHOUT MOST OF THIS PERIOD. SOME
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND
EARLY EVENING EACH DAY LEADING TO MVFR OR LOWER CONDITIONS. SOUTHEAST
WIND GUSTS UNDER 15 KNOTS ON MONDAY AND THEN SOUTHWEST WIND GUSTS
AROUND OR UNDER 20 KNOTS ON TUESDAY. PATCHY FOG POSSIBLE MONDAY
MORNING BEFORE 12Z.
&&
.MARINE...
AFTER COORDINATING WITH THE DAY SHIFT, WE HAVE DECIDED TO ISSUE A
DENSE FOG ADVISORY FOR OUR AREA WATERS THROUGH FRIDAY MORNING.
SOME OF THE TRAFFIC CAMS ALONG THE IMMEDIATE COAST LOOKED VERY
FOGGY. LATEST SREF/NARRE AND HRRR GUIDANCE ARE INDICATING THAT THE
FOG SHOULD CONTINUE AND SPREAD THROUGH THE NIGHT. NOT A CONFIDENT
FORECAST OFF OF MONMOUTH AND IN UPPER DELAWARE BAY AND TIMING
MIGHT HAVE TO BE EXTENDED ON FRIDAY AS FLOW REMAINS WEAK AND DEW
POINTS ABOVE WATER TEMPS.
SUB SCA CONDITIONS WITH FAIR WEATHER TONIGHT AND FRIDAY. THERE IS
SOME FOG ACROSS SE NJ/DEL COASTAL AREAS AND INTO SRN DEL BAY AND
EVEN INTO THE AFTERNOON...IT CONTINUES . IT WILL PROBABLY REMAIN INTO
THE EVENING AND PERHAPS BECOME A BIT MORE CONCENTRATED OVERNIGHT. VERY
LIGHT ONSHORE OR UP THE BAY FLOW INTO EARLY TONIGHT THEN
LIGHT/VARIABLE OVERNIGHT.
OUTLOOK...
SEAS AND WINDS ARE LIKELY TO REMAIN BELOW SCA CRITERIA THROUGH MONDAY
WITH SEAS NEAR FIVE FEET MONDAY NIGHT AND TUESDAY AS A COLD FRONT
APPROACHES. WINDS WILL BE MAINLY FROM THE SOUTH AND SOUTHEAST THROUGH
MONDAY THEN FROM THE SOUTHWEST UNDER 15 KNOTS WITH GUSTS UNDER 20
KNOTS, HIGHEST ON TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ016-
020>027.
DE...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR DEZ001>004.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...GIGI/JOHNSON/O`HARA
SHORT TERM...O`HARA
LONG TERM...GAINES
AVIATION...GAINES/GIGI/JOHNSON
MARINE...GAINES/GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
245 PM EDT FRI MAY 8 2015
.DISCUSSION...
REST OF THIS AFTERNOON-TONIGHT...NOT MUCH CHANGE IN THE ONGOING
WEATHER THROUGH THE REMAINDER OF THE DAY AS AREA REMAINS UNDER VERY
DRY NORTHWEST FLOW ON THE FAR SOUTHWEST SIDE OF SUBTROPICAL STORM
ANA NEAR THE SOUTH CAROLINA COAST. SEA BREEZE HAS DEVELOPED ALONG
THE BREVARD AND TREASURE COAST WHICH WILL KEEP TEMPERATURES AT THEIR
CURRENT LEVELS WITH OTHER LOCATIONS MAXING OUT IN THE NEXT HOUR OR
TWO IN THE MID TO UPPER 80S.
MOSTLY CLEAR SKIES FOR TONIGHT THOUGH WITH SOME PASSING MID LEVEL
CLOUDS AS A FEW WEAK VORTICITY MAXES ROTATE AROUND THE LARGER ANA
CIRCULATION. NOT TOO MUCH MOISTURE IN THE REGION TO WORK WITH SO
DON`T EXPECT ANY LAND IMPACTS...BUT WILL SEE A FEW SHOWERS OR STORMS
OVER THE ATLANTIC AND GULF STREAM. OVERNIGHT LOWS IN THE MID-UPPER
60S.
SATURDAY...ANOTHER PLEASANT LATE SPRING DAY AS ANA MEANDERS FURTHER
NORTH AND HIGH PRESSURE BEGINS TO NOSE IN FROM THE ATLANTIC.
NORTHWEST WIND COMPONENT WILL BE LIGHTER ALLOWING FOR QUICKER
DEVELOPMENT OF THE SEA BREEZE ALONG THE ENTIRE COAST EARLY IN THE
AFTERNOON.
CONDITIONS WILL REMAIN TOO DRY FOR ANY NOTABLE RAIN CHANCES OVER
LAND THROUGH THE DAY. HIGH TEMPS REACHING INTO THE UPPER 80S/AROUND
90 INLAND AND MID-UPPER 80S COAST.
SAT NIGHT-SUN NIGHT...
THE LOW LEVEL ATLANTIC RIDGE WILL CONTINUE TO NUDGE BACK ACROSS
THE PENINSULA AS ANA LIFTS SLOWLY NORTH TOWARDS THE COASTAL
CAROLINAS. THIS WILL TURN LOW LEVEL WINDS TO SOUTHERLY WHICH WILL
CAUSE MOISTURE LEVELS TO INCREASE. PRECIPITABLE WATER VALUES IN
THE 1.3 TO 1.5 RANGE WILL KEEP POPS LOW THOUGH. EXPECT SOME MARINE
CONVECTION SAT NIGHT...THEN WITH DAYTIME HEATING...ISOLATED SEA
BREEZE SHOWERS AND STORMS SHOULD FORM...STARTING IN THE SOUTH AND
WORKING NORTHWARD.
MOS POPS ARE NEAR 20 PERCENT IN THE SOUTH AND SINGLE DIGITS IN
THE NORTH FOR SUNDAY...THEN 20 PERCENT EVERYWHERE AFTER SUNSET
SUNDAY. THINK THAT EAST/WEST COAST BOUNDARY COLLISION WOULD BE A
LITTLE EARLIER...SO HAVE PAINTED 20 POPS AREAWIDE ON SUNDAY.
WE ARE GETTING INTO THE HIGHER SUN ANGLE NOW SO MAX TEMPS WILL
START REACHING THE LOWER 90S INLAND AND UPPER 80S AT THE COAST
WITH MILD OVERNIGHT LOWS IN THE UPPER 60S TO LOWER 70S.
MON-FRI...(MODIFIED PREVIOUS DISCUSSION)
THE BLOCKING RIDGE THAT IS KEEPING ANA STATIONARY WILL BREAK DOWN
BY THE START OF THE WORK WEEK AS IT IS ERODED FROM THE WEST AND
NORTH BY AN ADVANCING FRONTAL TROF OVER THE CENTRAL PLAINS/UPR
MIDWEST. THIS WILL ALLOW ANA TO DRIFT INTO THE CAROLINAS BY
DAYBREAK MON WHERE SHE WILL START TO ACCELERATE NORTHEAST AND
EVENTUALLY BE ABSORBED BY THE LOW PRESSURE SYSTEM MOVING THROUGH
THE GREAT LAKES AND INTO NEW ENGLAND.
AS THE ABOVE SCENARIO PLAYS OUT...THE ATLC RIDGE AXIS WILL REBUILD
OVER CENTRAL FL...WHERE IT WILL BCM THE PRIMARY WX FEATURE THRU THE
MIDDLE OF NEXT WEEK. REGIONAL H100-H70 WINDS WILL SHIFT TO THE S/SE
BY DAYBREAK MON AND REMAIN IN PLACE...TAPPING AN AIRMASS OVER THE
GREATER ANTILLES THAT SIMPLY DOES NOT HAVE SUFFICIENT MOISTURE TO
SUPPORT WIDESPREAD PRECIP. RAP ANALYSIS CONTINUE TO SHOW H100-H70 RH
VALUES AOB 70PCT...NOT CONDUCIVE FOR ANYTHING MORE THAN LOW END SCT
POPS.
EVEN SO...AS THE RIDGE AXIS DRIFTS OVERHEAD...THE WX PATTERN WILL
SHIFT TO A MORE SUMMER LIKE REGIME WITH ISOLD/SCT SHRAS/TSRAS
GENERATED BY DIURNALLY DRIVEN SEA BREEZE CONVERGENCE. WILL GO WITH
20-30PCT THRU WED... HIGHER OVER THE INTERIOR GIVEN THE ANTICIPATED
SE FLOW COMPONENT...INCREASING TO 30/40PCT ON THU AS MOISTURE
LOADING SLOWLY INCREASES. MAX TEMPS NEAR CLIMO AVG (M/U80S)...MIN
TEMPS ARND 5F ABV AVG (L/M70S).
&&
.AVIATION...VFR. EAST COAST SEA BREEZE WILL PUSH ACROSS PENINSULA
AROUND SUNSET WITH LIGHT WEST WINDS OVERNIGHT. LIGHT FLOW SHOULD
ALLOW QUICKER DEVELOPMENT AND INLAND MOVEMENT OF SEA BREEZE ON
SATURDAY.
&&
.MARINE...
TONIGHT-SATURDAY...WAVE HEIGHTS HAVE STARTED TO DIMINISH AT LOCAL
BUOYS AND WILL CONTINUE TO DO SO THROUGH THE REMAINDER OF THE
AFTERNOON AND EVENING...SO WILL ALLOW CURRENT ADVISORY TO EXPIRE
IN FAVOR OF A CAUTIONARY STATEMENT FOR THIS EVENING. SLOW DOWNWARD
TREND WILL BRING SEAS TO 3-4FT WITH UP TO 5FT LATE TONIGHT AND
INTO SATURDAY. MODELS SEEM A LITTLE TOO SHORT WITH DOMINANT WAVE
PERIODS SO WILL KEEP THEM CLOSER TO OBSERVATIONS AT 9-10SEC.
WESTERN ATLANTIC RIDGE AXIS NOSING INTO AREA ON SATURDAY AS
SUBTROPICAL STORM ANA MOVES FURTHER NORTH WILL KEEP FLOW FAIRLY
LIGHT WITH PREVAILING WEST 5-10KTS OVERNIGHT BECOMING E-SE WITH SEA
BREEZE DEVELOP IN THE AFTERNOON.
SUN-WED...THE AXIS OF THE ATLANTIC HIGH PRESSURE RIDGE WILL BUILD
INTO SOUTH FLORIDA SUNDAY AND THEN ACROSS CENTRAL FLORIDA ON MON.
THIS WILL CAUSE A SOUTHEAST/SOUTH WIND FLOW TO SET UP. THE
PRESSURE GRADIENT SHOULD SUPPORT AROUND 10 KNOTS BUT THE DAILY SEA
BREEZE CIRCULATION WILL ACCELERATE SPEEDS TO NEAR 15 KNOTS EACH
AFTERNOON/EVENING. A SLIGHT CHANCE FOR OFFSHORE MOVING
THUNDERSTORMS WILL EXIST IN THE AFTERNOON/EARLY EVENING...MAINLY
SUN/MON WHILE SOUTH SOUTHWEST STEERING FLOW CONTINUES. THEN BY
TUE/WED...DAYTIME HEATING STORMS SHOULD STAY OVER THE MAINLAND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 64 86 68 89 / 10 10 10 20
MCO 66 91 68 92 / 0 10 10 20
MLB 65 85 70 87 / 10 10 10 20
VRB 64 86 69 88 / 10 10 10 20
LEE 67 89 69 92 / 0 10 10 20
SFB 67 89 69 91 / 0 10 10 20
ORL 68 90 70 92 / 0 10 10 20
FPR 64 87 69 88 / 10 10 10 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...MOSES
LONG TERM....LASCODY
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
441 AM EDT FRI MAY 8 2015
.DISCUSSION...
TODAY...
SUBTROPICAL STORM ANA OFFSHORE OF THE SOUTH CAROLINA COAST WILL MOVE
ONLY SLOWLY NORTHWARD TODAY. SOME MOISTURE IN THE MID/UPR LEVELS IS
FORECAST TO PIVOT SOUTH TOWARD VOLUSIA AND BREVARD COUNTIES INTO THE
AFTERNOON. SHORT RANGE MODELS TRY TO GENERATE SOME SPOTTY LIGHT
PRECIP AMOUNTS BUT OVERALL DRYNESS TO THE AIRMASS SHOULD LIMIT
SHOWER COVERAGE BELOW 15 PERCENT. WILL KEEP FORECAST DRY WITH NW LOW
LVL FLOW. SHOULD SEE AN EAST COAST BREEZE DEVELOP ALONG THE COAST
FROM THE NNE/NE AND PUSH SLOWLY INLAND INTO LATE AFTERNOON. HIGHS
WILL REACH THE MID-UPPER 80S. A NORTH TO NORTHEAST OCEAN SWELL WILL
PRODUCE A MODERATE RIP CURRENT RISK AT THE BEACHES.
TONIGHT...
00Z GFS HAS ANOTHER VORT LOBE SWINGING SE MAINLY ACROSS THE E
CENTRAL FL ATLANTIC WATERS WHICH SHOULD ALLOW FOR SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP OUT ACROSS THE OFFSHORE GULF STREAM
WATERS. OVER LAND...LOW LVL FLOW WILL BECOME NW FOR NRN AREAS AND W-
SW ACROSS THE TREASURE COAST WITH DRY WEATHER EXPECTED. SKIES WILL
BE MOSTLY CLEAR TO PARTLY CLOUDY WITH LOWS IN THE 60S.
SAT-SUN...
SUBTROPICAL STORM ANA IS TRAPPED BY A DEEP RIDGE AXIS EXTENDING FROM
THE NRN GOMEX TO THE MID ATLC COAST AND IS EXPECTED TO MEANDER OVER
THE CAROLINA COAST THRU THE UPCOMING WEEKEND. LITTLE TO NO PRECIP
CHANCES AS THE POSITION OF ANA WILL KEEP CENTRAL FL UNDER HER
DESCENDING LEFT FLANK...CHARACTERIZED BY DEEP NWRLY FLOW...LARGE
SCALE SUPPRESSION... AND WEAK MOISTURE ADVECTION. INDEED...MODEL
GUIDANCE INDICATES A SHALLOW BUT SIGNIFICANT SUBSIDENCE INVERSION IN
THE H85-H70 LYR WITH SUBSTANTIAL DRY AIR AND NO ORGANIZED MID/UPR
LVL DYNAMIC LIFT ABV IT. WHAT LITTLE PRECIP DOES OCCUR WILL BE FAR
MORE THE EXCEPTION THAN THE RULE...MOST LIKELY IN THE FORM OF LIGHT
TO MODERATE SHRAS AS DEEP LYR NW FLOW IS ONE OF THE LEAST FAVORABLE
FLOW REGIMES FOR DEEP CONVECTION IN CENTRAL FL.
WILL GO WITH A SLGT CHC OF SHRAS SUN AFTN AS THE ATLC RIDGE AXIS...
CURRENTLY OVER THE SRN BAHAMAS/GREATER ANTILLES...LIFTS INTO S FL
AND WEAKENS THE LOW/MID LVL PGRAD ENOUGH TO ALLOW THE EAST COAST
SEA BREEZE TO DVLP WHILE LIGHT WRLY STEERING FLOW KEEPS IT PINNED
NEAR THE COAST. ACTUALLY...THE LOW LEVEL CYCLONIC FLOW AND SLIGHTLY
INCREASED LOW LEVEL MOISTURE MIGHT BE MORE OF A SIGNAL OF
CONSIDERABLE STRATUS DURING THE OVERNIGHT/MORNING HRS...BUT
NUMERICAL GUIDANCE IS NOT PICKING UP ON THIS ATTM. TEMPS NEAR AVG
SAT/SAT NIGHT AS THE NW FLOW THRU THE H100-H70 LYR WILL NOT PROMOTE
WARM AIR ADVECTION. TEMPS A FEW DEG ABV AVG SUN/SUN NIGHT AS H100-
H70 WINDS SHIFT TO THE S/SE.
MON-THU...
THE BLOCKING RIDGE THAT IS KEEPING ANA STATIONARY WILL BREAK DOWN BY
THE START OF THE WORK WEEK AS IT IS ERODED FROM THE WEST BY A
FRONTAL TROF OVER THE CENTRAL PLAINS/UPR MIDWEST...AND FROM THE EAST
BY ANA HERSELF. THIS WILL ALLOW ANA TO DRIFT INTO THE CAROLINAS BY
DAYBREAK MON WHERE SHE WILL BE ABSORBED BY A SECOND STORM SYSTEM
EXPECTED TO LIFT OUT OF THE DESERT SW.
AS THE ABOVE SCENARIO PLAYS OUT...THE ATLC RIDGE AXIS WILL REBUILD
OVER CENTRAL FL...WHERE IT WILL BCM THE PRIMARY WX FEATURE THRU THE
MIDDLE OF NEXT WEEK. REGIONAL H100-H70 WINDS WILL SHIFT TO THE S/SE
BY DAYBREAK MON AND REMAIN IN PLACE...TAPPING AN AIRMASS OVER THE
GREATER ANTILLES THAT SIMPLY DOES NOT HAVE SUFFICIENT MOISTURE TO
SUPPORT WIDESPREAD PRECIP. RAP ANALYSIS CONTINUE TO SHOW H100-H70 RH
VALUES AOB 70PCT...NOT CONDUCIVE FOR ANYTHING MORE THAN LOW END SCT
POPS.
EVEN SO...AS THE RIDGE AXIS DRIFTS OVERHEAD...THE WX PATTERN WILL
SHIFT TO A MORE SUMMER LIKE REGIME WITH ISOLD/SCT SHRAS/TSRAS
GENERATED BY DIURNALLY DRIVEN SEA BREEZE CONVERGENCE. WILL GO WITH
20-30PCT THRU WED... HIGHER OVER THE INTERIOR GIVEN THE ANTICIPATED
SE FLOW COMPONENT...INCREASING TO 30/40PCT ON THU AS MOISTURE
LOADING SLOWLY INCREASES. MAX TEMPS NEAR CLIMO AVG (M/U80S)...MIN
TEMPS ARND 5F ABV AVG (L/M70S).
&&
.AVIATION...
VFR FLYING WX EXPECTED AS SOME VFR MID LVL CIGS AFFECT NRN/CENTRAL
TERMINALS TODAY. ANY CONVECTIVE DEVELOPMENT LOOKS TO OCCUR OFFSHORE
TONIGHT WITH VFR CONDS AT TERMINALS CONTINUING.
&&
.MARINE...
TODAY-TONIGHT...HIGHER SEAS TO 6-7 FT WILL LINGER ACROSS THE OFFSHORE
WATERS NORTH OF SEBASTIAN INLET INTO THE AFTERNOON AND WILL EXTEND
THE SMALL CRAFT ADVISORY THERE UNTIL 4 PM. A 3-5 FT SWELL WILL
AFFECT THE NEAR SHORE WATERS WITH SOME 6 FT SWELLS AFFECTING THE
NEAR SHORE VOLUSIA WATERS TODAY. FOR TONIGHT...A GRADUAL DECREASE IN
SWELLS HEIGHTS IS EXPECTED BUT MAY NEED TO CONTINUE CAUTION
OFFSHORE. A CHANCE FOR SHOWERS/LIGHTNING STORMS WILL OCCUR ACROSS
THE OFFSHORE WATERS TONIGHT AS ANOTHER MID LVL DISTURBANCE PIVOTS SE
AROUND THE CIRCULATION OF ANA.
SAT-TUE...ATLC RIDGE AXIS OVER THE SRN BAHAMAS/GREATER ANTILLES WILL
GRADUALLY REBUILD INTO CENTRAL FL AS SUBTROPICAL STORM ANA DRIFTS
INTO THE CAROLINAS. GENTLE TO MODERATE W/SW BREEZE SAT MRNG WILL
SHIFT TO THE E/SE BY LATE SAT AFTN AND REMAIN IN PLACE INTO EARLY
NEXT WEEK. SEAS 3-4FT NEARSHORE AND 4-5FT OFFSHORE EARLY
SAT...SUBSIDING TO 2-3FT NEARSHORE AND 3-4FT OFFSHORE BY SUNSET SAT
AND CONTG THRU THE REMAINDER OF THE FCST.
&&
.FIRE WEATHER...
MIN RHS TO AROUND 40 PERCENT ACROSS THE INTERIOR WITH NW WINDS TO 10
MPH TODAY. SHOULD BE DRY WITH NO HEADLINES NEEDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 84 64 86 68 / 10 10 0 10
MCO 87 66 91 68 / 10 10 0 10
MLB 85 65 85 70 / 10 10 10 10
VRB 85 64 86 69 / 10 10 10 10
LEE 87 67 89 69 / 10 0 0 10
SFB 87 67 89 69 / 10 10 0 10
ORL 87 68 90 70 / 10 10 0 10
FPR 85 64 87 69 / 10 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR FLAGLER
BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-VOLUSIA-
BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM/AVIATION...VOLKMER
LONG TERM/IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION
NWS LINCOLN IL
901 PM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 901 PM CDT SAT MAY 9 2015
SCATTERED SHOWERS CONTINUE ACROSS THE AREA THIS EVENING AND WITH
REMNANTS OF ANOTHER MCS COMING IN FOR LATER TONIGHT...SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE OVERNIGHT. SKIES
WILL REMAIN MOSTLY CLOUDY SO DO NOT THINK MUCH FOG WILL OCCUR LATE
TONIGHT LIKE LAST NIGHT. CLOUDS WILL KEEP TEMPS UP AS WELL AND
CURRENT FORECAST LOW LOOKS FINE. GIVEN RADAR TRENDS HAVE MADE SOME
ADJUSTMENTS TO THE POP/WX GRIDS. SO UPDATE WILL BE COMING SHORTLY.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 251 PM CDT SAT MAY 9 2015
A QUASI-STATIONARY FRONTAL BOUNDARY FROM JUST SOUTH OF ST LOUIS AND
FLORA TO TERRE HAUTE WILL SLOWLY LIFT BACK NORTH AS A WARM FRONT
TOWARD I-72 TONIGHT (STAYING SOUTH OF I-72 TONIGHT). AREA OF SHOWERS
AND THUNDERSTORMS WITH SOME HEAVY RAIN WAS ALONG AND SOUTH OF A
TAYLORVILLE TO MATTOON TO PARIS LINE AND LIFTING SLOWLY NORTHWARD.
THIS ASSOCIATED WITH MCV EAST OF ST LOUIS AND SLOWLY TRACKING NNE
INTO SW IL AT MID AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD
NORTHWARD ACROSS CENTRAL IL LATE THIS AFTERNOON AND EVENING WHILE
BECOMING MORE SCATTERED IN SOUTHEAST IL AS THEY GET INTO THE WARM
SECTOR. TAIL END OF HRRR MODEL AND RAP13 MODEL SHOW MORE CONVECTION
SPREADING NE INTO SW CWA LATER TONIGHT AHEAD OF YET ANOTHER MCV OVER
EASTERN OK. SPC KEEPS MARGINAL RISK OF SEVERE STORMS SW OF IL OVER
MO THROUGH TONIGHT. A FEW STRONGER THUNDERSTORMS COULD HAVE WIND
GUSTS OVER 40 MPH WITH PEA SIZE HAIL AND HEAVY RAINS NEAR 1 INCH IN
LESS THAN AN HOUR. LOWS TONIGHT RANGE FROM UPPER 50S TO AROUND 60F
NORTH OF LINCOLN TO THE MID 60S FROM JACKSONVILLE AND SPRINGFIELD TO
MATTOON SOUTH.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 251 PM CDT SAT MAY 9 2015
UNSETTLED AND UNSEASONABLY MILD WEATHER PATTERN WILL PERSIST ACROSS
CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. STILL A COUPLE MORE
WAVES IN THE PERSISTENT SOUTHWESTERLY FLOW ALOFT NEED TO MOVE
THROUGH THE AREA BEFORE THE VIGOROUS CUT-OFF UPPER LOW OVER THE FOUR
CORNERS REGION FINALLY DRIVES A COLD FRONT THROUGH THE AREA. THIS
FRONT WILL BE FOLLOWED BY COOLER & DRIER AIR FOR MUCH OF THE WORK
WEEK.
SUNDAY SHOULD START OUT WITH SHOWERS/STORMS ACROSS MUCH OF THE
REGION AS A DISTURBANCE, CURRENTLY PRODUCING VIGOROUS CONVECTION
ACROSS THE SOUTHERN PLAINS, TRACKS NORTHEAST ACROSS THE AREA. DO NOT
EXPECT THE MORNING STORMS TO BE SEVERE. THEN, ATTENTION TO THE UPPER
AND ASSOCIATED SURFACE LOW THAT WILL BE PICKING UP STEAM AS IT TRACK
NORTHEAST ACROSS THE PLAINS. A WARM FRONT EXTENDING SOUTHEAST FROM
THE LOW ACROSS THE MIDWEST WILL LIFT NORTH THROUGH THE DAY. STILL
SOME SIGNIFICANT MODEL DISAGREEMENT WITH RESPECT TO HOW QUICKLY THE
FRONT LIFTS NORTHWARD. THE POSITION OF THIS FRONT DURING PEAK
HEATING WILL BE KEY TO WHERE THE BEST SEVERE WEATHER THREAT WILL
EXIST. AT THIS POINT, IT APPEARS THE BEST SHEAR/INSTABILITY WILL CO-
EXIST ACROSS THE NORTHERN PORTION OF THE FORECAST AREA INTO NORTHERN
ILLINOIS. THE SHEAR PROFILES WILL BE SUBSTANTIALLY MORE IMPRESSIVE
FURTHER NORTHWEST, ACROSS IOWA, CLOSER TO THE TRACK OF THE
UPPER/SURFACE LOW. THE LOWS WILL TRACK ACROSS THE GREAT LAKES ON
MONDAY DRAGGING THE TRAILING COLD FRONT THROUGH ILLINOIS. STILL SOME
MODEL DISAGREEMENT IN THE SPEED OF THE COLD FRONT, WHICH WILL BE KEY
TO THE SEVERE WEATHER THREAT ON MONDAY. THE NAM, WHICH HAD BEEN THE
QUICKEST MODEL, IS NOW AMONG THE SLOWEST SOLUTIONS. CONTINUE TO
FAVOR A SLOWER SOLUTION GIVEN THE CURRENT POSITION/SPEED OF THE
SYSTEM OVER THE SOUTHWEST STATES, AND A TYPICAL MODEL BIAS OF BEING
TOO QUICK MOVING CUT-OFF LOWS. THESE FACTORS CONSIDERED, IT APPEARS
THAT THE BEST THREAT FOR SEVERE WEATHER ON MONDAY LOCALLY IS ACROSS
EAST CENTRAL AND SOUTHEAST ILLINOIS DURING THE MONDAY
AFTERNOON/EARLY EVENING HOURS.
QUIETER AND COOLER WEATHER IS EXPECTED TO ARRIVE MONDAY NIGHT AND
LINGER FOR MUCH OF THE REMAINDER OF THE WEEK. DAYTIME HIGHS THAT HAD
FREQUENTLY BEEN IN THE 80S AHEAD OF THE FRONT WILL MAINLY BE IN THE
60S AFTER FRONTAL PASSAGE. THE ECMWF, WHILE SLOWER THAN IT WAS A
COUPLE DAYS AGO, IS STILL THE QUICKEST TO BRING A SYSTEM BACK INTO
THE AREA BY THE END OF THE WEEK AS SOUTHWEST UPPER-LEVEL FLOW
REDEVELOPS AND TEMPERATURES TEND TO CLIMB BACK TOWARD NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 652 PM CDT SAT MAY 9 2015
LIGHT SHOWERS CONTINUE TO MOVE NORTHEAST ACROSS THE AREA,
EFFECTING ALL TAF SITES FOR NEXT 3-4HRS. THEN THERE SHOULD BE A
BREAK IN THE PCPN CHANCES UNTIL THE NEXT POSSIBLE SHOWERS/T-STORMS
WILL BE OVERNIGHT AS REMNANTS OF ONGOING CONVECTION IN SOUTHERN
AND WESTERN MO MOVES UP INTO THE AREA. SO WILL HAVE VCTS FOR ALL
SITES OVERNIGHT. WILL HAVE IT ALL NIGHT, THOUGH WILL NOT BE THAT
LONG. HOWEVER, TIMING UNCERTAIN RIGHT NOW. BY MORNING, THINGS
SHOULD DISSIPATE AS THE FRONT BEGINS TO LIFT NORTH OF THE AREA.
HOWEVER, WITH LOTS OF LOW LEVEL MOISTURE AROUND, WILL HAVE HZ FOR
ALL SITES. WINDS WILL BE LIGHT BUT EASTERLY THIS EVENING BUT
BECOME NORTHEAST AT PIA AND BMI WITH FRONT JUST TO THE SOUTH, AND
SOUTHEAST AT SPI/DEC/CMI. BY MORNING, ALL SITES SHOULD BE SOUTH OF
FRONT SO WILL HAVE SOUTHEAST TO SOUTH AT ALL SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...07
LONG TERM...BAK
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
652 PM CDT SAT MAY 9 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 251 PM CDT SAT MAY 9 2015
A QUASI-STATIONARY FRONTAL BOUNDARY FROM JUST SOUTH OF ST LOUIS AND
FLORA TO TERRE HAUTE WILL SLOWLY LIFT BACK NORTH AS A WARM FRONT
TOWARD I-72 TONIGHT (STAYING SOUTH OF I-72 TONIGHT). AREA OF SHOWERS
AND THUNDERSTORMS WITH SOME HEAVY RAIN WAS ALONG AND SOUTH OF A
TAYLORVILLE TO MATTOON TO PARIS LINE AND LIFTING SLOWLY NORTHWARD.
THIS ASSOCIATED WITH MCV EAST OF ST LOUIS AND SLOWLY TRACKING NNE
INTO SW IL AT MID AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD
NORTHWARD ACROSS CENTRAL IL LATE THIS AFTERNOON AND EVENING WHILE
BECOMING MORE SCATTERED IN SOUTHEAST IL AS THEY GET INTO THE WARM
SECTOR. TAIL END OF HRRR MODEL AND RAP13 MODEL SHOW MORE CONVECTION
SPREADING NE INTO SW CWA LATER TONIGHT AHEAD OF YET ANOTHER MCV OVER
EASTERN OK. SPC KEEPS MARGINAL RISK OF SEVERE STORMS SW OF IL OVER
MO THROUGH TONIGHT. A FEW STRONGER THUNDERSTORMS COULD HAVE WIND
GUSTS OVER 40 MPH WITH PEA SIZE HAIL AND HEAVY RAINS NEAR 1 INCH IN
LESS THAN AN HOUR. LOWS TONIGHT RANGE FROM UPPER 50S TO AROUND 60F
NORTH OF LINCOLN TO THE MID 60S FROM JACKSONVILLE AND SPRINGFIELD TO
MATTOON SOUTH.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 251 PM CDT SAT MAY 9 2015
UNSETTLED AND UNSEASONABLY MILD WEATHER PATTERN WILL PERSIST ACROSS
CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. STILL A COUPLE MORE
WAVES IN THE PERSISTENT SOUTHWESTERLY FLOW ALOFT NEED TO MOVE
THROUGH THE AREA BEFORE THE VIGOROUS CUT-OFF UPPER LOW OVER THE FOUR
CORNERS REGION FINALLY DRIVES A COLD FRONT THROUGH THE AREA. THIS
FRONT WILL BE FOLLOWED BY COOLER & DRIER AIR FOR MUCH OF THE WORK
WEEK.
SUNDAY SHOULD START OUT WITH SHOWERS/STORMS ACROSS MUCH OF THE
REGION AS A DISTURBANCE, CURRENTLY PRODUCING VIGOROUS CONVECTION
ACROSS THE SOUTHERN PLAINS, TRACKS NORTHEAST ACROSS THE AREA. DO NOT
EXPECT THE MORNING STORMS TO BE SEVERE. THEN, ATTENTION TO THE UPPER
AND ASSOCIATED SURFACE LOW THAT WILL BE PICKING UP STEAM AS IT TRACK
NORTHEAST ACROSS THE PLAINS. A WARM FRONT EXTENDING SOUTHEAST FROM
THE LOW ACROSS THE MIDWEST WILL LIFT NORTH THROUGH THE DAY. STILL
SOME SIGNIFICANT MODEL DISAGREEMENT WITH RESPECT TO HOW QUICKLY THE
FRONT LIFTS NORTHWARD. THE POSITION OF THIS FRONT DURING PEAK
HEATING WILL BE KEY TO WHERE THE BEST SEVERE WEATHER THREAT WILL
EXIST. AT THIS POINT, IT APPEARS THE BEST SHEAR/INSTABILITY WILL CO-
EXIST ACROSS THE NORTHERN PORTION OF THE FORECAST AREA INTO NORTHERN
ILLINOIS. THE SHEAR PROFILES WILL BE SUBSTANTIALLY MORE IMPRESSIVE
FURTHER NORTHWEST, ACROSS IOWA, CLOSER TO THE TRACK OF THE
UPPER/SURFACE LOW. THE LOWS WILL TRACK ACROSS THE GREAT LAKES ON
MONDAY DRAGGING THE TRAILING COLD FRONT THROUGH ILLINOIS. STILL SOME
MODEL DISAGREEMENT IN THE SPEED OF THE COLD FRONT, WHICH WILL BE KEY
TO THE SEVERE WEATHER THREAT ON MONDAY. THE NAM, WHICH HAD BEEN THE
QUICKEST MODEL, IS NOW AMONG THE SLOWEST SOLUTIONS. CONTINUE TO
FAVOR A SLOWER SOLUTION GIVEN THE CURRENT POSITION/SPEED OF THE
SYSTEM OVER THE SOUTHWEST STATES, AND A TYPICAL MODEL BIAS OF BEING
TOO QUICK MOVING CUT-OFF LOWS. THESE FACTORS CONSIDERED, IT APPEARS
THAT THE BEST THREAT FOR SEVERE WEATHER ON MONDAY LOCALLY IS ACROSS
EAST CENTRAL AND SOUTHEAST ILLINOIS DURING THE MONDAY
AFTERNOON/EARLY EVENING HOURS.
QUIETER AND COOLER WEATHER IS EXPECTED TO ARRIVE MONDAY NIGHT AND
LINGER FOR MUCH OF THE REMAINDER OF THE WEEK. DAYTIME HIGHS THAT HAD
FREQUENTLY BEEN IN THE 80S AHEAD OF THE FRONT WILL MAINLY BE IN THE
60S AFTER FRONTAL PASSAGE. THE ECMWF, WHILE SLOWER THAN IT WAS A
COUPLE DAYS AGO, IS STILL THE QUICKEST TO BRING A SYSTEM BACK INTO
THE AREA BY THE END OF THE WEEK AS SOUTHWEST UPPER-LEVEL FLOW
REDEVELOPS AND TEMPERATURES TEND TO CLIMB BACK TOWARD NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 652 PM CDT SAT MAY 9 2015
LIGHT SHOWERS CONTINUE TO MOVE NORTHEAST ACROSS THE AREA,
EFFECTING ALL TAF SITES FOR NEXT 3-4HRS. THEN THERE SHOULD BE A
BREAK IN THE PCPN CHANCES UNTIL THE NEXT POSSIBLE SHOWERS/T-STORMS
WILL BE OVERNIGHT AS REMNANTS OF ONGOING CONVECTION IN SOUTHERN
AND WESTERN MO MOVES UP INTO THE AREA. SO WILL HAVE VCTS FOR ALL
SITES OVERNIGHT. WILL HAVE IT ALL NIGHT, THOUGH WILL NOT BE THAT
LONG. HOWEVER, TIMING UNCERTAIN RIGHT NOW. BY MORNING, THINGS
SHOULD DISSIPATE AS THE FRONT BEGINS TO LIFT NORTH OF THE AREA.
HOWEVER, WITH LOTS OF LOW LEVEL MOISTURE AROUND, WILL HAVE HZ FOR
ALL SITES. WINDS WILL BE LIGHT BUT EASTERLY THIS EVENING BUT
BECOME NORTHEAST AT PIA AND BMI WITH FRONT JUST TO THE SOUTH, AND
SOUTHEAST AT SPI/DEC/CMI. BY MORNING, ALL SITES SHOULD BE SOUTH OF
FRONT SO WILL HAVE SOUTHEAST TO SOUTH AT ALL SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...BAK
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
316 AM CDT FRI MAY 8 2015
.SHORT TERM...(TODAY)
ISSUED AT 316 AM CDT FRI MAY 8 2015
SPC MESOANALYSIS INDICATING A VERY WEAK SHORTWAVE OVER PARTS OF WEST
CENTRAL ILLINOIS EARLY THIS MORNING WHICH HAS BROUGHT A BAND OF
SHOWERS AND ISOLATED THUNDERSTORMS TO AREAS MAINLY ALONG AND WEST OF
INTERSTATE 55 OVERNIGHT. LOCAL OBJECTIVE ANALYSIS INDICATING MOST
UNSTABLE CAPES IN THE ORDER OF 400-800 J/KG THRU THE LATE EVENING
AND EARLY MORNING HOURS WITH THE PAST COUPLE OF HOURS DEPICTING A
TREND DOWNWARD IN ELEVATED CAPES. SHORTWAVE ENERGY OVER PARTS OF THE
SOUTHERN PLAINS THIS MORNING HAS A LARGE AREA OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH IT AND THAT UPPER WAVE AND PRECIP ARE
FORECAST BY SHORT TERM MODELS TO PUSH INTO WEST CENTRAL IL BY MID TO
LATE MORNING AND OVER THE REMAINDER OF THE FORECAST AREA THIS
AFTERNOON. THE BREAK BETWEEN OUR OVERNIGHT SHOWERS AND THE SOUTHERN
STREAM DISTURBANCE SHOULD ALLOW TEMPERATURES TO WARM INTO THE 80S
AGAIN MOST AREAS WHICH SHOULD PRODUCE MIXED LAYER CAPES IN THE ORDER
OF 1500 J/KG. 0-6KM BULK SHEAR VALUES ONLY AROUND 20 KTS THIS
AFTERNOON SO IT LOOKS LIKE THE SAME SETUP AS YESTERDAY AFTERNOON
WITH THE CONVECTION BEING DIURNALLY DRIVEN WITH A PEAK IN STORMS MID
TO LATE AFTERNOON AND MAINLY SCATTERED SHOWERS AND ISOLATED THUNDER
BY LATE THIS EVENING. WARMEST TEMPS TODAY WILL BE ACROSS THE EAST
WHERE THEY SHOULD ENJOY A LONGER DURATION OF SUNSHINE.
&&
.LONG TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 316 AM CDT FRI MAY 8 2015
SIMILAR FORECAST YET AGAIN WITH VERY LITTLE IN THE WAY OF CHANGES
DUE TO A WET FORECAST FOR THE WEEKEND AND WIDESPREAD LIKELY AND HIGH
CHANCE POPS. PLENTY OF CLOUDS OVER THE AREA AND WAA WITH SOUTHERLY
WINDS KEEPING PLENTY OF MOISTURE OVER THE REGION FOR THE SERIES OF
WAVES MOVING INTO THE MIDWEST FROM THE DESERT SW. LOW OVER THE
SOUTHWESTERN CONUS ESTABLISHING A SOUTHWESTERLY FLOW PATTERN INTO
THE MIDWEST. BOTH A FRONT SETTLING INTO THE REGION LATER TONIGHT AND
A SERIES OF SMALL WAVES ROTATING AROUND THE TROF IN THE SW WILL SET
UP A RATHER WET WEEKEND. THOUGH THERE WILL LIKELY BE BREAKS IN SOME
OF THE RAINFALL, FORECAST FOR SHOWERS AND THUNDERSTORMS DOMINATES
THE WEEKEND. FINALLY SEE THE MAIN UPPER LOW LIFT OUT OF THE SW SUN
NIGHT/MONDAY...WITH A STORMY OUTLOOK FOR THE SFC AS A TRUE COLD
FRONT PUSHES THROUGH THE REGION. TIMING FOR THE BOUNDARY ON MONDAY
WILL BE CLOSELY WATCHED AS THERE IS A DECENT CHANCE FOR SOME OF THE
STORMS TO BECOME SEVERE WITH A MIX OF INSTABILITY WITH STRONG
SOUTHERLY FLOW AHEAD OF THE SYSTEM...AND DEEP LAYER SHEAR WITH THE
UPPER LOW LIFTING OUT. COOLER TEMPS AND DRY WEATHER EXPECTED FOR
TUE/WED AS THE AIRMASS SHIFTS EAST AND COLDER AIR FILTERS INTO THE
REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1155 PM CDT THU MAY 7 2015
A LINE OF SHOWERS AND ISOLATED STORMS WILL LINGER FOR SEVERAL MORE
HOURS ACROSS CENTRAL IL, GENERALLY CENTERED ALONG THE I-55
CORRIDOR. SOME BACK BUILDING HAS CAUSED THE LINE TO LINGER BACK
ACROSS SPRINGFIELD, BUT THERE SHOULD BE PROGRESS OF THE BACK EDGE
TO THE NORTHEAST IN THE NEXT FEW HOURS. PIA SHOULD BE JUST WEST OF
THE PRECIP, WHILE CMI REMAINS EAST OF THE PRECIP FOR THE MOST
PART. ELEVATED INSTABILITY HAS REMAINED SUFFICIENT ENOUGH OF
LIGHTNING DEVELOPMENT AND WILL CONTINUE WITH VCTS AT BMI/DEC/SPI
FOR A COUPLE HOURS. VFR CONDITIONS SHOULD PREVAIL, BUT BRIEF
PERIODS OF MVFR VIS IN HEAVIER RAIN COULD DEVELOP, BUT NOT ENOUGH
TO WARRANT A TEMPO GROUP.
WINDS WILL BE VARIABLE NEAR SHOWERS/STORMS, BUT SHOULD GENERALLY RETURN
TO A S-SW DIRECTION BY 09-10Z. WINDS WILL BECOME MORE PROMINENTLY SOUTHWEST
AFTER SUNRISE TOMORROW AND INCREASE TO AROUND 10-12KT BY
AFTERNOON.
THE HRRR IS SHOWING THE NEXT ROUND OF SHOWERS AND STORMS SHOULD
BEGIN TO AFFECT SPI TOWARD 18Z, EXPANDING NE WITH TIME. SHOWERS
COULD LINGER INTO THE EVENING, BUT THE STRONGER STORMS SHOULD BE
DURING THE AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1156 PM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 901 PM CDT THU MAY 7 2015
THE SHORTWAVE ASSOCIATED WITH THE LINE OF SHOWERS WILL PROGRESS TO
THE EAST-NORTHEAST ACROSS CENTRAL AND EASTERN IL THE REST OF THE
NIGHT. INSTABILITY HAS WEAKENED TO THE POINT THAT VERY FEW LIGHTNING
STRIKES HAVE BEEN DETECTED IN THE LAST HOUR OR SO. WILL KEEP AN
ISOLATED THUNDER MENTION IN THE GRIDS OVERNIGHT, AS THE WAVE
DEPARTS TO OUR NE EVENTUALLY. THERE SHOULD BE A BREAK IN THE
PRECIP LATER TONIGHT AND FRIDAY MORNING BEFORE THE NEXT SYSTEM
ARRIVES FROM THE SW. BETTER CHANCES OF STORMS RE-DEVELOPING LOOKS
TO BE FRIDAY AFTERNOON.
TEMPS DROPPED WITH THE PASSAGE OF A GUST FRONT AHEAD OF THE LINE
OF RAIN, BUT THE SYNOPTIC COLD FRONT REMAINS WEST OF ILLINOIS. SO
THE OVERALL AIRMASS WILL REBOUND ONCE THE PRECIP ENDS TONIGHT. WE
WILL CONTINUE WITH RELATIVELY MILD LOWS IN THE MID 60S.
UPDATES THIS EVENING WERE APPLIED TO THE WEATHER, POPS, SKY AND
WIND GRIDS TO MATCH EXPECTED TRENDS. UPDATED FORECAST INFO IS
ALREADY AVAILABLE.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 259 PM CDT THU MAY 7 2015
SCATTERED SHOWERS AND THUNDERSTORMS OVER MO AND IA INTO INTO THE MS
RIVER VALLEY OF IL WILL SPREAD NE ACROSS CENTRAL IL LATE THIS
AFTERNOON AND INTO TONIGHT. MODELS HAVE THE CONVECTION WEAKENING
AFTER SUNSET WITH LOSS OF INSTABILITY AND BECOMING MORE ISOLATED IN
EASTERN IL OVERNIGHT SO HAVE TRENDED POPS FROM 50-60% IN WEST-
CENTRAL IL LATE THIS AFTERNOON AND TONIGHT TO ISOLATED IN EASTERN
IL BY OVERNIGHT. SPC HAS MARGINAL RISK WEST OF A PEORIA TO
JACKSONVILLE LINE WHERE CAPES PEAK FROM 1200-1800 J/KG THROUGH
00Z/7 PM. MAINLY SMALL HAIL POSSIBLE THIS AFTERNOON AND EARLY
EVENING UNTIL SUNSET. GETTING A FEW HALF TO THREE QUARTER INCH
SIZE HAIL REPORTS PAST HOUR OVER NE MO AND FUNNEL CLOUD REPORT
NEAR HANNIBAL MO. COLD FRONT JUST NW OF IA INTO CENTRAL KS TO PUSH
INTO SE IA AND NW MO BY SUNRISE FRI. MILD LOWS MOSTLY IN THE MID
60S TONIGHT WITH BREEZY SSW WINDS 10-20 MPH AND GUSTS OF 20-35 MPH
THIS AFTERNOON DIMINISHING TO AROUND 10 MPH AFTER SUNSET.
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 259 PM CDT THU MAY 7 2015
AN ACTIVE AND UNSEASONABLY MILD WEATHER PATTERN IS EXPECTED TO
PERSIST ACROSS CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. MAIN
FORECAST CONCERN REVOLVES AROUND SHOWER/THUNDERSTORM TIMING AND
INTENSITY THROUGH MONDAY. UNFORTUNATELY, THE LIMITS OF
PREDICTABILITY WITH CONVECTIVE WEATHER MAKE THE DETAILS TOUGH TO
PINPOINT TOO FAR OUT.
THE FRONTAL BOUNDARY THAT CURRENTLY EXTENDS THROUGH THE UPPER
MIDWEST AND INTO THE SOUTHERN PLAINS WILL CONTINUE TO MAKE SLOW
EASTWARD PROGRESS THE NEXT FEW DAYS, EVENTUALLY CLEARING THE AREA
ON MONDAY. THE PASSAGE OF THIS FRONT WILL END THE UNSETTLED
WEATHER PATTERN AND PUSH TEMPERATURES BELOW NORMAL FOR MUCH OF
NEXT WEEK.
EXPECT A DIURNALLY INDUCED MAXIMUM COVERAGE OF SHOWERS/STORMS INTO
SATURDAY AS THERE DOES NOT APPEAR TO BE A SIGNIFICANT UPPER LEVEL
FEATURE TO FOCUS PRECIPITATION BY THEN, AND NO SIGNIFICANT NOCTURNAL
LOW LEVEL JET IS EXPECTED EITHER. THE SEVERE THREAT THROUGH SATURDAY
ALSO LOOKS TO BE SPOTTY AT BEST GIVEN WEAK SHEAR PROFILES AND MOSTLY
MODEST INSTABILITY. WHILE THE INSTABILITY IS LIKELY TO BECOME MUCH
BETTER BY SATURDAY AFTERNOON, PEAKING IN EXCESS OF 1500 J/KG, SHEAR
PROFILES STILL DON`T SUPPORT ORGANIZED SEVERE WEATHER.
THE CUTOFF UPPER LOW, CURRENTLY ALONG THE CALIFORNIA COAST, WILL
FINALLY GET MOVING AND PASS WEST/NORTH OF THE FORECAST AREA SUNDAY
INTO MONDAY. THIS IS THE FEATURE THAT WILL EVENTUALLY DRIVE THE
SURFACE FRONT THROUGH THE AREA. ITS APPROACH/PASSAGE WILL ALSO
PROVIDE ENHANCED SHEAR PROFILES LOCALLY (TO GO ALONG WITH GOOD
DIURNAL INSTABILITY) IN THE WEST ON SUNDAY AND AREA-WIDE FOR
MONDAY. THESE DAYS WILL BE OUR MOST LIKELY TIME FOR SEVERE STORMS,
ESPECIALLY MONDAY.
ONCE THE COLD FRONT CLEARS THE AREA MONDAY, QUIET AND COOLER WEATHER
WILL BE WITH US FOR MUCH OF THE WEEK. DAILY HIGH TEMPERATURES THAT
HAD BEEN MAINLY IN THE 80S THE PAST SEVERAL DAYS, WILL FALL INTO THE
60S, WHICH IS BELOW NORMAL FOR EARLY/MID MAY. THE COOLER/QUIETER
WEATHER WILL ARRIVE ALONG WITH A STRONG CANADIAN AREA OF HIGH
PRESSURE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1155 PM CDT THU MAY 7 2015
A LINE OF SHOWERS AND ISOLATED STORMS WILL LINGER FOR SEVERAL MORE
HOURS ACROSS CENTRAL IL, GENERALLY CENTERED ALONG THE I-55
CORRIDOR. SOME BACK BUILDING HAS CAUSED THE LINE TO LINGER BACK
ACROSS SPRINGFIELD, BUT THERE SHOULD BE PROGRESS OF THE BACK EDGE
TO THE NORTHEAST IN THE NEXT FEW HOURS. PIA SHOULD BE JUST WEST OF
THE PRECIP, WHILE CMI REMAINS EAST OF THE PRECIP FOR THE MOST
PART. ELEVATED INSTABILITY HAS REMAINED SUFFICIENT ENOUGH OF
LIGHTNING DEVELOPMENT AND WILL CONTINUE WITH VCTS AT BMI/DEC/SPI
FOR A COUPLE HOURS. VFR CONDITIONS SHOULD PREVAIL, BUT BRIEF
PERIODS OF MVFR VIS IN HEAVIER RAIN COULD DEVELOP, BUT NOT ENOUGH
TO WARRANT A TEMPO GROUP.
WINDS WILL BE VARIABLE NEAR SHOWERS/STORMS, BUT SHOULD GENERALLY RETURN
TO A S-SW DIRECTION BY 09-10Z. WINDS WILL BECOME MORE PROMINENTLY SOUTHWEST
AFTER SUNRISE TOMORROW AND INCREASE TO AROUND 10-12KT BY
AFTERNOON.
THE HRRR IS SHOWING THE NEXT ROUND OF SHOWERS AND STORMS SHOULD
BEGIN TO AFFECT SPI TOWARD 18Z, EXPANDING NE WITH TIME. SHOWERS
COULD LINGER INTO THE EVENING, BUT THE STRONGER STORMS SHOULD BE
DURING THE AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...07
LONG TERM...BAK
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
643 AM EDT FRI MAY 8 2015
.SYNOPSIS...
ISSUED AT 415 AM EDT FRI MAY 8 2015
THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY AHEAD OF A
WEAK FRONTAL BOUNDARY. A WAVE OF LOW PRESSURE WILL MOVE ALONG THIS
FRONT LATER TODAY AND THIS EVENING AS THE BOUNDARY SAGS INTO THE
LOCAL AREA. THIS WILL INCREASE THE CHANCES FOR SHOWERS AND
THUNDERSTORMS THIS EVENING. IT WILL BE ANOTHER WARM AND HUMID DAY
BUT NOT QUITE AS WARM AS THURSDAY. HIGHS WILL BE AROUND 80 NORTH
AND IN THE MID 80S SOUTH. LOWS TONIGHT WILL ONCE AGAIN REMAIN IN
THE 60S WITH MUGGY CONDITIONS AND A CHANCE FOR SHOWERS AND
THUNDERSTORMS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM EDT FRI MAY 8 2015
UPPER LOW ALONG WEST COAST WILL MOVE INLAND THIS PERIOD WHILE
SEVERAL WEAK SHORT WAVES EJECT NORTHEAST AND MOVE THROUGH THE
GREAT LAKES REGION. FORCING REMAINS WEAK WITH THESE WAVES BUT
MOISTURE CONTINUES TO INCREASE IN DEEP SOUTHWEST FLOW WITH
PRECIPITABLE WATER VALUES CLIMBING TO OVER 1.5 INCHES. MODELS
STRUGGLING WITH CONVECTIVE DEVELOPMENT GIVEN WEAK FLOW AND
FORCING. EXPECT WE WILL SEE A COUPLE DIFFERENT ROUNDS OF SCATTERED
CONVECTION BUT AFRAID MODELS ARE OVERDONE ON COVERAGE AND
INTENSITY INITIALLY TODAY. RADAR MOSAIC SHOWS AREA OF DECAYING
SHOWERS IN EASTERN IL AT 08Z WITH FIRST WEAK WAVE. THIS AREA MAY
CLIP FAR WESTERN COUNTIES EARLY THIS MORNING. HAVE SLOWLY
INCREASED POPS FROM WEST TO EAST TODAY BUT DID STAY IN THE CHANCE
RANGE THROUGH MID AFTERNOON.
SLIGHTLY BETTER WAVE APPROACHES LATE AFTERNOON INTO THIS EVENING AS
WEAK SURFACE BOUNDARY SAGS INTO THE AREA. A WEAK SFC LOW EXPECTED TO
DEVELOP ALONG FRONT WHICH SHOULD AID IN LOW LEVEL CONVERGENCE AND
HELP DEVELOP A LARGER AREA OF SHOWERS AND STORMS. TIMING WILL ALSO
BE FAVORABLE WITH SFC BASED CAPES IN THE 1-2K J/KG RANGE AND PWATS
POSSIBLY EXCEEDING 1.5 INCHES. SHEAR REMAINS WEAK SO SEVERE WEATHER
THREAT IS LOW BUT LOCALLY HEAVY DOWNPOURS POSSIBLE. TRENDED POPS TO
LIKELY NEAR AND NORTH OF EXPECTED BOUNDARY LATE THIS AFTERNOON AND
TONIGHT.
TEMPERATURES STILL EXPECTED TO REACH INTO THE 80S TODAY DESPITE
INCREASED CLOUD COVER AND RAIN THREAT. SATELLITE EARLY THIS MORNING
SHOWS PLENTY OF BREAKS AND IT WILL NOT TAKE MUCH TO HEAT UP GIVEN
WARM START AND WARM TEMPS ALOFT. CLOUDS TONIGHT SHOULD HELP KEEP
LOWS IN THE 60S ONCE AGAIN.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 413 AM EDT FRI MAY 8 2015
SUMMERLIKE WARMTH AND PERIODIC CHANCES FOR SHOWERS/STORMS WILL
HIGHLIGHT THE SATURDAY THROUGH MONDAY PERIODS AS DEEP
SOUTHWESTERLY FLOW PERSISTS OVER A WEAK FRONTAL BOUNDARY THAT WILL
BE IN THE VICINITY. LOW-AMPLITUDE/CONVECTIVELY AIDED MID LEVEL
DISTURBANCES EMBEDDED IN THIS WEAK SW FLOW WILL HELP AID DEEPER
CONVERGENCE ALONG THIS FRONTAL BOUNDARY AT TIMES...WITH HIGH POPS
WARRANTED GIVEN AMPLE MOISTURE...ALTHOUGH WEAK FORCING/FLOW LIMITING
FACTORS FOR ANYTHING MORE THAN 50/60 TYPE POPS THROUGH THE WEEKEND.
WESTERN CONUS BROAD TROUGH/EMBEDDED CLOSED LOW WILL LIFT NORTHEAST
THROUGH THE MID/UPPER MS VALLEY/WESTERN LAKES BY LATER SUNDAY
NIGHT-MONDAY. THE LOCAL AREA SHOULD GET INTO THE SYSTEM WARM SECTOR
FOR A TIME AS ASSOCIATED SFC REFLECTION TRACKS ENE INTO WISCONSIN.
TIGHTENING OF THE MID LEVEL HEIGHT GRADIENT ATOP THIS INCREASINGLY
UNSTABLE PREFRONTAL AIRMASS MAY SET THE STAGE FOR STRONG/SEVERE
STORMS ALONG TRAILING CDFNT BY MONDAY AFTN...ALTHOUGH AS ALWAYS
THREAT WILL BE HIGHLY CONDITIONAL...DEPENDENT ON DIURNAL
TIMING/DESTABILIZATION. COOLER/DRIER AIR WILL THEN FILTER IN POST
FRONTAL TUESDAY-THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 638 AM EDT FRI MAY 8 2015
WEAK UPPER WAVE MOVING NORTHEAST THROUGH IL THIS MORNING COUPLED
WITH LOW LEVEL JET WAS GENERATING A FEW SHOWERS OVER NORTHEAST IL.
RADAR TRENDS INDICATE THIS RAIN MAY STAY JUST WEST OF KSBN THIS
MORNING. WHILE ISOLATED SHOWERS MAY STILL DEVELOP THIS
MORNING...EXPECT BETTER CHANCE FOR RAIN THIS AFTERNOON AND
TONIGHT...ESPECIALLY CLOSER TO KSBN. STRONGER SHORT WAVE TO MOVE
THROUGH WHILE WEAK SFC FRONT SAGS INTO THE AREA. SHOULD SEE
ADDITIONAL SHOWERS AND A FEW TSRA. HIRES RUC13 WANTS TO KEEP MOST
ACTIVITY WEST OF KFWA BUT NAM12 AND GFS MORE AGGRESSIVE ON
EASTWARD PUSH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...STEINWEDEL
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
416 AM EDT FRI MAY 8 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 307 AM EDT FRI MAY 8 2015
A FRONTAL SYSTEM IS EXPECTED TO DROP SOUTHEAST INTO OR NEAR THE
LOCAL AREA OVER THE WEEKEND. A STRONGER COLD FRONT IS EXPECTED TO
MOVE THROUGH THE AREA AROUND NEXT MONDAY. IN THE WAKE OF THIS
FRONT...HIGH PRESSURE WILL BUILD IN FOR THE MIDDLE PARTS OF NEXT
WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 307 AM EDT FRI MAY 8 2015
MODEL DATA INDICATE MID LEVEL TEMPERATURES MAY BE A LITTLE COOLER
THAN THEY WERE YESTERDAY...WHICH MAY RESULT IN BETTER CHANCES FOR
CONVECTION TODAY THAN THERE HAS BEEN. THAT BEING SAID...DON/T REALLY
SEE MUCH IN THE WAY OF A TRIGGER TODAY...OTHER THAN THE POTENTIAL
FOR A COUPLE OF OUTFLOW BOUNDARIES MOVING EAST OUT OF ILLINOIS.
ANOTHER POSSIBILITY IS THE REMNANT VORTICITY ASSOCIATED WITH THE
CONVECTION CURRENTLY OVER SOUTHWEST MISSOURI AND WESTERN
ARKANSAS...WHICH MAY APPROACH THE WESTERN ZONES TOWARDS EVENING.
BASED ON ABOVE...WILL KEEP POPS IN THE CHANCE CATEGORY TODAY FOR
MAINLY THE AFTERNOON HOURS. HIGHEST POPS WEST.
LOW LEVEL THICKNESSES SUGGEST THE GFS MOS HIGHS FOR TODAY LOOK
GOOD.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 307 AM EDT FRI MAY 8 2015
SOUTHWESTERLY UPPER FLOW EXPECTED ACROSS THE OHIO VALLEY DURING THIS
PERIOD AS LONG WAVE UPPER TROUGH CURRENTLY OVER THE WESTERN STATES
GRADUALLY SHIFTS EAST INTO THE WESTERN PLAINS BY SUNDAY NIGHT.
DISTURBANCES EJECTING OUT OF THE WESTERN TROUGH MAY PERIODICALLY
ENHANCE CHANCES FOR CONVECTION DURING THIS PERIOD...BUT TIMING OF
THESE INDIVIDUAL WAVES IS DIFFICULT AT THIS TIME. THERE ARE ALSO
QUESTIONS REVOLVING HOW FAR SOUTH A FRONTAL ZONE...CURRENTLY OVER
THE NORTHERN MIDWEST...MAY GET THIS WEEKEND. DUE TO THE
UNCERTAINTIES OF THE TIMING OF THE INDIVIDUAL WAVES AND FUTURE
LOCATION OF THE FRONTAL ZONE...WILL KEEP POPS IN THE CHANCE CATEGORY
THROUGH SUNDAY NIGHT FOR NOW. THE EXCEPTION WILL BE TONIGHT...WHERE
MODELS SUGGEST A BELT OF STRONGER 850MB FLOW WILL CROSS THE
NORTHWEST ZONES TONIGHT. WILL GO WITH LIKELY POPS IN THOSE AREAS
TONIGHT.
BASED ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS LOWS FOR
TONIGHT AND SATURDAY NIGHT LOOK A LITTLE COOL...ESPECIALLY OVER THE
NORTH. WILL RAISE THE GUIDANCE A FEW DEGREES IN THOSE PERIODS.
GUIDANCE HIGHS SATURDAY AND SUNDAY LOOK OK AT THIS POINT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 307 AM EDT FRI MAY 8 2015
THE STORMY UNSETTLED PATTERN WILL CONTINUE TO START THE WORK
WEEK...QUICKLY TRANSITIONING TO A COOLER DRIER REGIME AS AN UPPER
TROUGH EVENTUALLY SETTLES OVER NEW ENGLAND.
EXTENDED MODELS REMAIN CONSISTENT WITH LOW PRESSURE TRACKING FROM
THE UPPER MISSISSIPPI VALLEY E/NE INTO QUEBEC MONDAY AND TUESDAY.
THIS WILL FINALLY BRING A COLD FRONT THROUGH THE OHIO VALLEY LATE
MONDAY WITH SHOWERS AND THUNDERSTORMS LIKELY AS A 40KT+ LOW LEVEL
JET ROTATES INTO THE REGION. POTENTIAL STILL EXISTS FOR STRONG TO
SEVERE STORMS WITH FAVORABLE UPPER LEVEL DYNAMICS AND A MOIST
UNSTABLE AIRMASS PRESENT OVER CENTRAL INDIANA. PRECIPITATION WILL
END MONDAY NIGHT AS HIGH PRESSURE POKES INTO THE REGION FROM THE
SOUTHWEST.
HIGH PRESSURE WILL BECOME THE MAIN INFLUENCE FOR MUCH OF THE REST OF
THE WEEK WITH TEMPERATURES FALLING BACK TO COOLER THAN NORMAL LEVELS
AS AN UPPER TROUGH TRANSITIONS INTO THE NORTHEAST STATES. OP GFS
BECOMES AN OUTLIER AS THE WEEK PROGRESSES...HOLDING ONTO A MORE
AMPLIFIED TROUGH MUCH LONGER THAN THE GLOBAL MODELS. BULK OF THE GFS
ENSEMBLE MEMBERS DO NOT SUPPORT THE OP GFS EITHER. HAVE TRENDED
FORECAST TOWARDS THE GLOBAL MODELS...WITH THE UPPER FLOW BECOMING
QUASI-ZONAL FOR THE SECOND HALF OF THE WEEK. POTENTIAL FOR A FEW
STORMS COMES THURSDAY AND THURSDAY NIGHT AS WEAK LOW PRESSURE TRACKS
THROUGH THE REGION. ONCE THE FRONT PASSES MONDAY NIGHT...EXPECT
HIGHS MAINLY IN THE 60S FOR THE REST OF THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 080900Z TAF UPDATE/...
ISSUED AT 416 AM EDT FRI MAY 8 2015
DELAYED ARRIVAL OF MORE SUBSTANTIAL CLOUD COVER BY A COUPLE HOURS AS
IT HAS BEEN SLOWER TO EXPAND EAST INTO THE REGION SO FAR THIS
MORNING. CURRENT RAP STILL INDICATING DEEPER MOISTURE WILL ADVECT
INTO CENTRAL INDIANA THROUGH THE MORNING WITH A BROKEN CU FIELD
LIKELY BECOMING WELL ESTABLISHED.
06Z DISCUSSION FOLLOWS.
GENERALLY VFR THROUGH THIS MORNING AND THE REST OF TODAY...HOWEVER
THERE IS THE POSSIBILITY OF SOME LOWER FLIGHT CONDITIONS SUCH AS
MVFR OR EVEN IFR BEGINNING LATE THIS EVENING AND OVERNIGHT WITH
SHOWERS AND THUNDERSTORMS DEVELOPING AND MOVING THROUGH CENTRAL
INDIANA LATE IN THE AVIATION FORECAST PERIOD.
OTHERWISE...INCREASING MID AND HIGH CLOUDS WILL CONTINUE TO BE THE
TREND THROUGH EARLY THIS MORNING. MODEL AND OBSERVATIONAL TRENDS
STILL DEPICT THE PRECIPITATION WELL OFF TO THE WEST BREAKING UP AS
IT APPROACHES INDIANA LATE THIS MORNING. THERE ARE VERY WEAK CHANCES
SOME LIGHTLY SCATTERED SHOWERS COULD REACH THE WESTERN TERMINALS
(KHUF/KLAF) BY 9Z AND EASTERN ONES (KIND/KBMG) BY 12Z...HOWEVER
PROBABILITIES AND COVERAGE ARE SO LOW THAT THIS WILL NOT BE
MENTIONED AT THIS TIME.
THEN LATER TODAY ADDITIONAL SCATTERED CONVECTION MAY BEGIN POPPING
UP LATE THIS AFTERNOON...HOWEVER MORE LIKELY BY THE EVENING
HOURS...AND CONTINUING INTO THE OVERNIGHT. FOR NOW WILL INTRODUCE
THESE CHANCES TO THE TAFS AROUND 00Z WITH A BKN040 CB DECK AND
SHOWERS. CERTAINLY NOT CONFIDENT ENOUGH IN COVERAGE OF SHOWERS AND
DEFINITELY ANY THUNDERSTORMS AFFECTING AT PARTICULAR SITE AT A
SPECIFIC TIME AT THIS EARLY JUNCTURE...BUT BELIEVE AT THE VERY LEAST
A CB GROUP ALONG WITH VCTS IS WARRANTED.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...SMF/RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
642 PM CDT SAT MAY 9 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
QUIET FOR THE REST OF SATURDAY AND THEN STORM CHANCES ENTER THE FCST
LATE IN THIS SHORT TERM PERIOD. A POCKET OF DRIER AIR HAS BEEN IN
PLACE MOST OF SATURDAY AFTERNOON ACROSS THE CWA ALLOWING FOR
SUNSHINE TO PUNCH THROUGH ACROSS THE CENTRAL TO NORTHERN PARTS OF
OUR CWA.
THE LARGE AREA OF LOW PRESSURE WE HAVE BEEN TALKING ABOUT
FOR THE PAST FEW DAYS HAS REACHED THE FOUR CORNERS REGION OF THE
CONUS. THIS LOW IS SLATED TO BE LOCATED OVER WESTERN NEBRASKA BY 12Z
SUN. THE NAM IS A SLIGHT OUTLIER...KEEPING THIS SYSTEM SLOWER AND
FURTHER TO THE SOUTH THAN THE REST OF GUIDANCE. THE GFS IS THE
FASTEST. LEANED TOWARDS THE EURO...WHICH IS IN THE MIDDLE...FOR
TIMING. FOR LOW LEVEL MOISTURE INIT...USUAL MODEL BIASES IN PLACE.
THE NAM IS THE MOST MOIST...WHILE THE GFS IS OVERLY DRY. LEANED
TOWARDS EURO ONCE AGAIN.
AHEAD OF THIS AREA OF LOW PRESSURE...A WARM FRONT WILL BE PASSING
THROUGH OUR CWA FROM SW TO NE. ALL MODELS SHOW THE GULF IS WIDE OPEN
FOR MOISTURE TRANSPORT VIA THE LLJ...THE NOSE OF WHICH WILL BE ALONG
THE WESTERN/CENTRAL PART OF OUR CWA AT 12Z SUN. REGARDING THE SEVERE
WEATHER POTENTIAL...THE RAP SHOWS 0-1KM BULK SHEAR VALUES IN THE 20
TO 25KT RANGE...HELICITY IN THE 200 TO 400 RANGE AND LOW ENOUGH LCL
HEIGHTS TO SUGGEST TORNADOES MAY BE A SEVERE MODE THREAT EARLY ON.
DCAPE VALUES ARE ALSO HIGH EARLY ON...SO DAMAGING WINDS IS ALSO A
THREAT. LOCATION-WISE...THIS WILL MAINLY BE IN THE WESTERN/SW CWA AT
12Z. THE EVOLUTION OF SUNDAY/S SEVERE WEATHER WILL BE HANDLED IN THE
LONG TERM.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SEVERE WEATHER POTENTIAL FOR
SUNDAY INTO SUNDAY NIGHT. THE REMAINDER OF THE FORECAST TIME FRAME
REMAINS RELATIVELY QUIET UNTIL LATE IN THE WORK WEEK.
SUNDAY INTO SUNDAY NIGHT...POTENTIAL EXISTS FOR AT LEAST TWO
ROUNDS OF SEVERE WEATHER ON MOTHERS DAY...WITH THE MORNING
CONVECTION SURGING NORTHWARD WITH THE WARM FRONT THROUGH 15Z AND
THEN THE DIURNALLY DRIVEN CONVECTION IN THE AFTERNOON ALONG THE
DRY LINE BY THE LATE AFTERNOON/EARLY EVENING. LEANED TOWARD THE
NAM12/ARWWRF FOR TIMING OF POPS SUNDAY INTO SUNDAY NIGHT EVEN
THOUGH MODELS ARE IN FAIRLY GOOD AGREEMENT WRT TO SURFACE LOW
TRACK AND TIMING OF COLD FROPA SUNDAY EVENING. THIS RESULTED IN
DELAYING THE AFTERNOON CONVECTION SLIGHTLY AS INITIATION LOOKS TO
BE AFTER 20Z SUNDAY OVER WESTERN PORTIONS OF THE FORECAST AREA.
THE WARM FRONT LOOKS TO SURGE NORTHWARD TO THE IOWA/MINNESOTA
BORDER BY AROUND 00Z MONDAY WITH THE SURFACE LOW CENTERED OVER
FAR NORTHWEST CORNER OF IOWA AND FAR SOUTHEAST SOUTH DAKOTA. THE
STRONGER AND DEEPER FORCING FOR ASCENT IS IN THIS LOCATION BUT
QUESTIONABLE WHETHER SURFACE INSTABILITY RECOVERS ENOUGH TO
SUPPORT LOW-LIVED TORNADIC SUPERCELLS. HOWEVER...ENOUGH ELEVATED
MUCAPE PRESENT COMBINED WITH STRONG LOW LEVEL SHEAR AND VORTICITY
WITHIN THE VICINITY OF THE WARM FRONT LOOKS TO COUNTERACT THE LACK
OF SURFACE INSTABILITY AND CERTAINLY PROVIDE A DECENT THREAT FOR
TORNADOES AND LARGE HAIL OVER WEST-CENTRAL TO NORTH-CENTRAL IOWA
TOMORROW AFTERNOON. DEEP LAYER SHEAR FROM 50 TO NEAR 70 KNOTS
PLENTY STRONG ENOUGH TO KEEP CONVECTION THROUGH THE EVENING SUNDAY
AS THE COLD FRONT PUSHES ACROSS IOWA. SEVERE POTENTIAL EXISTS
ALONG THE COLD FRONT WITH STRAIGHT-LINE WINDS THROUGH ROUGHLY 03Z
MONDAY BEFORE ENVIRONMENT BECOMES LESS FAVORABLE. THINKING ANY
SUPERCELLS THAT DEVELOP LATE TOMORROW AFTERNOON WILL MORPH INTO A
QLCS TYPE STRUCTURE WITH THE ADVANCEMENT OF THE COLD FRONT...WHICH
WOULD KEEP THE ROUNDS OF SEVERE WEATHER AT ONLY TWO. IF CONVECTION
PUSHES NORTH INTO MINNESOTA THEN A THIRD ROUND ALONG THE COLD
FRONT SEEMS FEASIBLE TOMORROW EVENING WITHIN THE DMX CWA.
MONDAY THROUGH WEDNESDAY...STRONG CAA DEVELOPS ON MONDAY INTO
MONDAY NIGHT AND MAY SEE A FEW SHOWERS ACROSS THE NORTH WITH
SOME WRAP-AROUND MOISTURE FROM THE SURFACE LOW. OTHERWISE...COOL
AND DRY CONDITIONS THROUGH WEDNESDAY.
THURSDAY INTO SATURDAY...LARGE UPPER LEVEL RIDGE BEGINS TO BREAK
DOWN WITH A FAIRLY STRONG VORT MAX EJECTING OUT OF THE SOUTHERN
ROCKIES THURSDAY. UNCERTAINTY IN TIMING WITH THE ECMWF ROUGHLY 12
HOURS QUICKER THAN THE GFS. BY THE END OF THE WORK WEEK AND INTO
NEXT WEEKEND...THE REGION IS PLACED BACK INTO SOUTHWEST FLOW ALOFT
AND EXTENDED MODELS HAVE MULTIPLE SHORTWAVES TO AFFECT THE FORECAST
AREA.
&&
.AVIATION...10/00Z
ISSUED AT 642 PM CDT SAT MAY 9 2015
MAIN CONCERNS WILL BE EVOLUTION OF CONVECTION THROUGH THE PERIOD.
BOUNDARY AT THE SFC AND ALOFT OVER CENTRAL IA WILL RETREAT NORTH
AS WARM FRONT LATE NIGHT AND CARRY WITH IT SHOWERS AND THUNDER
FROM NEAR 10Z THROUGH 17Z SOUTH TO NORTHEAST. FOLLOWING THE
PASSAGE OF FRONT LOW CIGS WITH IFR/MVFR CIGS EXPECTED...THEN
BREAKS BUT REMAINING MAINLY MVFR THROUGH AFTERNOON AS NEXT ROUND
OF STRONGER CONVECTION ARRIVES FROM WEST/SOUTHWEST MOVING EAST
BEYOND END OF PERIOD. FOR NOW...HAVE TIMING AT 20-21Z ARRIVING SW
SECTIONS MOVING EAST THROUGH 04-06Z EAST. PER SPC AND LOCAL
ANALYSIS...SVR STORMS LIKELY ESPECIALLY IN AFTERNOON TIME FRAME.
WILL REFINE NEXT PACKAGE AT 06Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KOTENBERG
LONG TERM...PODRAZIK
AVIATION...REV
AREA FORECAST DISCUSSION
NWS TOPEKA KS
642 PM CDT Sat May 9 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Sunday)
Issued at 322 PM CDT SAT MAY 9 2015
An intense upper level trough was located across northwest NM. An 80
KT H5 jet max was lifting northeast across west TX into southwest
KS. A dryline was sharpening up from southeast CO, south-southeast
across the eastern TX PNHDL, then south into the hill country of
west central TX. The center of a lee cyclone, north of TAD. The warm
front extended east south-southeast from the lee cyclone, across
southwest KS, then east along the KS and OK border. A band of
elevated thunderstorms that formed across southeast CO and the TX
PNHDL earlier this morning continues to slowly move northeast across
central and south central KS. The area of elevated thunderstorms
were beginning to weaken as they move northeast into a more stable
airmass across eastern KS. An MCS was forming across central OK and
will move east-northeast across northeast OK into southwest MO.
The CWA will see a gradual increase in isolated to scattered shower
and thunderstorms late this afternoon, but with MUCAPES only 500 to
1000 J/KG these storms will not become severe this afternoon. As the
warm front begins to push north, the isentropic lift will begin to
weaken and we may see a break in the shower and thunderstorms
activity through the mid evening hours. Farther west, the atmosphere
is beginning to recover from the morning convection across the
eastern TX PNHDL, eastern CO and western KS. As the upper low over
northwest NM lifts northeast into east-central CO, numerous
thunderstorms should develop along the dryline as it begins to push
northeast across the eastern TX PNHDL into southwest KS and east
central CO. Intense upper level ascent ahead of the lifting upper
low will allow scattered supercell thunderstorms across western KS
to congeal into a QLCS or an MCS through the evening hours across
western KS. This storm complex will lift northeast across north
central KS late this evening and through the early morning hours of
Sunday. If a complex of thunderstorms develop the primary hazards
will be large hail, damaging winds and heavy rain. The meso-scale
models such as the RAP and WRF move the more intense portions of the
MCS north-northeast into southern NE just west of the CWA. Though,
there may be enough ascent that scattered thunderstorms will develop
south-southeast of this complex of thunderstorms. The primary hazard
of any severe thunderstorms across the CWA later Tonight will be
large hail, damaging wind gusts and heavy rainfall. The vertical
wind shear and MUCAPE do increase later Tonight, thus if a supercell
thunderstorm develops the boundary layer may not be decoupled enough
to prevent isolated tornadoes. However, at this time the better
chances for tornadic supercells will be this evening across western
KS.
Due to the uncertainty in the intensity and areal extent of wide
spread deep moist convection, I will not be issuing a flash flood
watch for the CWA. There is a chance for locally heavy rainfall with
any convective complex that develops. The isolated to scattered
thunderstorms later Tonight will move quickly to the northeast, so
expect only brief heavy rainfall. The better chances for heavy
rainfall will be associated with MCS`s that are forecasted to move
southeast and northwest of the CWA.
Sunday, there may be a few morning storms across the eastern
counties of the CWA. The upper low will begin to slowly fill as it
lifts northeast-northeast into western NE during the day. A strong
H5 jet max of 50 to 60 KTS will over spread eastern KS through the
afternoon hours. A cold front will quickly occlude the dryline
across central KS during the mid and late morning hours and the cold
front will push east across the western half of the CWA during the
early Afternoon hours. The numerical models all show the 850mb winds
slowly veering to the southwest ahead of the surface front. However,
the numerical models forecast southerly or even southeasterly
surface wind ahead of the surface front. The deepest gulf moisture
may get shunted eastward across MO into eastern IA but several
mesoscale models are showing 10 to 12 DEG Td at 850mb remaining
ahead of the surface front. There should be enough deep moisture and
instability for scattered thunderstorms to begin to develop along
the surface cold front by 20Z. The front should extend roughly from
a Seneca to Manhattan to Council Grove line by 3 PM. Thunderstorms
that develop will rapidly become severe given MLCAPES of 1500 to
2500 J/KG and SFC to 6KM effective shear of 50 to 60 KTS. Even
though 850mb winds begin to veer slightly the surface winds may
remain back. Therefore as storms first form they may be isolated to
scattered supercells before congealing into a squall line which will
then push east across northeast and east central KS during the late
afternoon hours. The 0-1 SRH of 150 to 250 J/KG may support any
discrete supercell to produce isolated tornadoes. Once the isolated
to scattered supercells merge into a squall line then the primary
hazards will be damaging winds gusts, large hail and heavy rainfall.
The line will move fairly fast across the eastern counties of the
CWA and begin to weaken after 6 PM due to the loss of surface
heating. Highs just behind the surface front across the central
counties of the CWA may reach to around 80 degrees, with most other
areas getting into the mid to upper 70s.
.LONG TERM...(Sunday Night through Saturday)
Issued at 322 PM CDT SAT MAY 9 2015
Sunday Night through Monday Night ...
By Sunday evening, models are in fairly good agreement with the
surface and mid-level patterns. A closed mid-level low should be
centered over the northern High Plains with the deep trough
stretching all the way southward toward the U.S./Mexico border. At
the surface, the center of low pressure should be focused across
northeast Nebraska with the associated cold front extending
southward and essentially bisecting the forecast area (i.e.,
stretching from Marysville to Manhattan to Herington by early
evening). This front placement is a bit further west than what
models were suggesting yesterday. Model soundings show little to no
inhibition in place across the area by late afternoon/early evening.
Expect decent advection of warm, moist air ahead of this boundary
from the breezy southerly winds, resulting in a decent set-up for
some strong to severe thunderstorms late afternoon into the evening
hours. Models suggest that isolated storms should develop along and
ahead of the cold front by late afternoon/early evening and quickly
congeal into a line of storms as the wind profiles look to prevail
out of the southwest. With a north/south oriented boundary, this
southwesterly flow should help to advance this line of storms fairly
quickly eastward across eastern KS with most of the forecast area
dry by midnight. Increasing low-level cloud cover combined with
little inhibition may result in slightly lower CAPE values upwards
of 1500-1800J/kg. Wind profiles show fairly unidirectional winds out
of the southwest with a 60-70kt 500mb jet, however there are some
discrepancies with regards to how much winds will veer in the lowest
2km of the atmosphere. As a result, there is a notable range amongst
the models in 0-1km helicity values across far eastern Kansas. LCL
values should be fairly low at around 3000ft or less, but the lapse
rates do not look that great. With these conditions and model
discrepancies in mind, confidence is low in the tornado threat
across eastern Kansas Sunday evening however an isolated tornado or
two still cannot be ruled out. Expect upwards of 50-60kts of 0-6km
shear, so combined with the modest instability the primary severe
threats look to be large hail and strong winds. Some locally heavy
rainfall will also be possible, which may potentially result in some
localized flash flooding and/or river flooding as some locations
have already received a few inches of rain this week. However, with
1-hr and 3-hr flash flood guidance near 2 inches, do not expect
widespread flooding concerns with these fast-moving storms.
Winds will slowly veer toward the west overnight into Monday morning
with clearing skies. As a result, decent radiational cooling should
help to drop low temperatures into the 40s. The mid-level trough
will lift northward out of the area through the day on Monday with
surface high pressure advancing into the High Plains behind this
exiting system. West-northwesterly surface winds will usher cooler
air into the region, keeping Monday high temperatures below normal
in the low/mid 60s. These cool conditions and mostly clear skies
will persist into Monday night with even cooler overnight low
temperatures in the upper 30s to mid 40s.
Tuesday through Saturday...
Tuesday will have mostly sunny skies and highs in the upper 60s,
with lows dropping into the upper 40s Tuesday night. The surface
high pressure aiding in these mild conditions will move southeast of
the area late evening, allowing winds to veer to the south by Wednesday
morning. This warm air advection will push highs into the lower
70s, before another system pushes into the area bringing chances for
precipitation every day for the rest of the period.
Models are still inconsistent with the handling this next system,
but agree with the previous forecast that the ECMWF solution seems
more reasonable. An upper-level wave will move NE into the central
plains by late Thursday bringing the best chances for thunderstorms
Wednesday night though Thursday night. Severe potential is still
low as the best CAPE/shear seems to be south or west of our area,
depending on the model. From here, thunderstorm chances remain until
Saturday, but confidence in timing and the overall pattern are
low.
&&
.AVIATION...(For the 00Z TAFs through 00Z Sunday Evening)
Issued at 642 PM CDT SAT MAY 9 2015
SHRA should be ending in 01-02Z window at TOP and FOE. At this
point have little confidence in when/if any additional convection
will impact the terminals through the overnight hours and will
monitor radar and guidance trends for possible inclusion. MVFR
cigs already forming in central KS and expect this trend to occur
here as well though of course much uncertainty in timing and
heights.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Heller/Hennecke
AVIATION...65
AREA FORECAST DISCUSSION
NWS TOPEKA KS
604 AM CDT Fri May 8 2015
...AVIATION UPDATE...
.SHORT TERM...(Today and Tonight)
Issued at 318 AM CDT FRI MAY 8 2015
08Z water vapor and profiler data suggests a vort max is passing
through southeast KS at this hour. Meanwhile a closed upper low
continues to dig southeast into southern CA. At the surface, a cold
front stretched from Manhattan to Hiawatha. Some dryer and cooler
air was moving into north central KS behind this front. The shower
activity over eastern KS should continue moving east of the area
with the vort max through the morning.
For today and tonight, models show a diffluent southwesterly flow
persisting across the area while the cold front gradually pushes
south of the forecast area and becomes diffuse. All of the model
guidance shows this boundary remaining mainly south of the forecast
area keeping the axis of instability further south and west today
and tonight. Meanwhile both low level and deep layer shear
parameters are pretty weak due to the stronger flow remaining to the
west in closer proximity of the upper low. With this in mind, can
see why the latest SWODY1 outlook shifted the risk for severe
weather mainly south of the forecast area. Think that a good portion
of the day may be dry. Subsidence behind the vort max in
southeastern KS should bring an end to the morning showers.
Meanwhile there does not appear to be any obvious forcing
immediately upstream. Therefore think the next round of precip is
likely to be the remnants of today`s convection over the southern
plains lifting north within the mid level flow. So the forecast
shows the better chances for precip (outside of the morning rain)
occurring this evening and overnight. With limited instability and
relatively weak shear this evening, think storms are more likely to
remain sub-severe with heavy rainfall remaining a risk.
Highs today are expected to be slightly cooler across the northern
counties due to the neutral to weak cold air advection in the
boundary layer. With this in mind have highs in the lower 70s north
to the mid 70s across east central KS. Lows tonight are forecast to
be in the upper 50s to lower 60s with possible rain cooled air off
setting increasing cloud cover.
.LONG TERM...(Saturday through Thursday)
Issued at 318 AM CDT FRI MAY 8 2015
Much of the focus in the long term is on the potential severe
weather on Saturday and perhaps Sunday. Strong upper low currently
over southern CA will lift eastward, entering eastern CO by Saturday
afternoon. Ahead of the upper level forcing, the surface low deepens
across western KS, while strong southerly flow advects a very moist
airmass into the region. Raised dewpoints slightly in the middle 60s
Saturday afternoon, with a break in precip to warm highs in the
upper 70s. In comparison, models have not deviated much from
previous forecasts with organized convection focused to develop
along/ahead of the dryline in western/central Kansas, tracking
eastward through the evening. Main uncertainties are the storm
modes, whether storms are discrete or focused in a line as they
approach northeast Kansas. This formation and subsequent hazards
will depend on timing of any areas of lift ahead of the main upper
trough and how much destabilization can occur in the warm sector
ahead of any overnight or morning convection. With that said, the
Storm Prediction Center has shifted their enhanced risk further west
to account for these uncertainties, continuing to include all of
northeast Kansas in the slight risk. A few of the short term models
such as the NAM12 and 4 KM WRF are indicating that there will be
some clearing with the exiting precip Saturday morning. This would
quickly increase SFC based CAPE to up to 2000 J/KG with forecast
soundings depicting very weak inhibition. Effective shear is more
optimal over central and north central areas at 30 to 40 KTS by 4
PM, while a strong low level jet increases 0-1 KM bulk shear values
from 20 to 30 KTS after 7 PM. Overall setup with the forecast will
have lower end chances for thunderstorms in the morning, increasing
in the afternoon as instability enhances while minor waves may spark
mid afternoon thunderstorms across the area. These storms may
produce large hail and strong winds, however believe the tornado
threat is low until the late afternoon and evening period when the
main wave lifts out and storms quickly surge eastward from the
dryline. Would expect convection to continue through the evening and
come to an end Sunday morning. All hazards of severe weather remain
possible, with more emphasis on potential for river and flash
flooding with saturated conditions in place.
Sunday remains conditional for severe weather as the upper trough
phases with the sfc low over eastern Nebraska. Subsidence behind the
boundary will spread across much of central and portions of
northeast Kansas by late afternoon, effectively ending chances for
severe storms. Latest GFS and ECMWF remain slower with the sfc low,
positioning the better instability over far eastern Kansas.
Meanwhile the GEM and NAM are further east, with the severe weather
potential in Missouri. With still some uncertainties, maintained a
chance for thunderstorms across far eastern Kansas during the late
afternoon. If storms develop, all severe hazards are possible.
The extended period finally becomes quite as the upper trough lifts
northward and shortwave ridging builds in through mid week.
Northerly winds and a cooler airmass will drop back highs into the
60s and lows in the 40s. Next chance for thunderstorms arrives on
Wednesday and Thursday as the next wave builds eastward towards the
southern plains. Better moisture resides over this area, but will
maintain low end chances with much discrepancies between guidance.
&&
.AVIATION...(For the 12Z TAFs through 12Z Saturday Morning)
Issued at 604 AM CDT FRI MAY 8 2015
Subsidence behind departing vort max should lead to dry conditions
through the day. Biggest uncertainty deals with MVFR CIGS behind
the front. RAP and NAM forecast soundings scatter out the lower
CIGS around 17Z, so have conditions improving early in the
afternoon. There may be more showers and storms tonight, but have
little confidence in timing these so will start out with a VCTS as
a first guess.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...Bowen
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1212 AM CDT Fri May 8 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Friday)
Issued at 405 PM CDT THU MAY 7 2015
Challenging forecast again tonight with somewhat disorganized
convection this evening and overnight. Band of stronger
thunderstorms forming in weak convergence and max instability axis
from central KS to southeast Nebraska. 0-6 km bulk shear in that
area in the 30 kt range while 0-1 km shear is weak. Storms could
display some organization with hail and wind the main severe
threats. Very heavy rain may also be a concern with slow storm
movement and the potential for some training. Showers and isolated
thunderstorms in east central KS in an area of weak isentropic lift
and have persisted for awhile today and are not going away by late
afternoon. RAP and last few HRRR runs have done alright with
development along boundary/instability axis and have this area
persist and then move southeast overnight. Heavy rain will be the
main threat later tonight.
Challenge for Friday is how much remnant showers/storms will occur
in the morning. Believe best chances of persistence into the
morning will be in east central Kansas. Several models are then
supportive of a shortwave impulse coming out of the southwest moving
into forecast area around early evening on Friday.
.LONG TERM...(Friday Night through Thursday)
Issued at 405 PM CDT THU MAY 7 2015
By Friday evening severe convection will form along the dry line
across far southwest KS. That area of convection will likely expand
in coverage as it moves northeastward through the overnight hours.
At the surface a warm front will begin to lift back northward into
the day Saturday. Convection looks to generally track along this
front passing through most of southern KS. Lapse rates decrease
during the evening hours as mid to upper 60 dewpoints spread into
the southern half of the forecast area. This places cape values in
the 1500-2500 j/kg valid at 00Z. Models agree that the cape will
decrease, but remains somewhat modest as the deep layer shear
increases to around 35 kts. The NAM is the most aggressive with an
increasing low level jet developing over southern KS as the storms
approach the area. Given the parameters in place strong to severe
storms are possible. The models are fairly consistent in bringing a
decent amount of QPF through the area by 12Z Sat. Flooding will
definitely be a concern especially given the recent rainfall and
saturated ground at some locations. There is a chance for a dry
period during the day Sat before the next round associated with the
main mid level low ejecting out of the Rockies. The chance for
severe storms overnight Saturday is greater across the area given
the dry line will be further east into central KS. Also, the deep
layer shear looks to be closer to 50 kts and the cape remains as
high as 2000 j/kg. Low level jet increases again leading to wind
profile favorable for supercells and possibly tornadoes. This threat
may diminish during the early morning hours as depicted by the NAM,
which barely brings QPF into the area overnight. The dry line
continues eastward as the main mid level low lifts through NE and
SD. By the time the atmosphere destabilizes the dry line will be
located somewhere in far eastern KS where storms are likely to form.
The vertical wind profile appears to be more unidirectional out of
the southwest, which is more parallel to the boundary possibly
leading to more cell interaction. So discrete supercells initially
may quickly transition into a cluster or line, and there is plenty
of cape and deep layer shear for these storms to be severe Sun
afternoon.
The upper level system finally begins to lift northeast late Sunday
into Monday and becomes and open wave by Tuesday over the Upper
Mississippi Valley. Dry and stable conditions are left in its wake,
which will be very needed by this point as the area needs to dry out
a bit before the next system develops. The upper levels will
transition to a more zonal flow pattern over the Central Plains.
Meanwhile, the next trough will begin to set up over the Western
CONUS. At this point, it could be a similar upper level pattern
developing as has recently been in place. However, at this point,
it doesn`t appear moisture recovery, necessary for as wet of a
pattern, will be in place at least through Thursday night. A quick
upper level shortwave may be ejected out of the Southern Rockies in
the afternoon time frame on Wednesday and possibly interact with a
weak warm boundary near the KS/NE border. There could be some
isolated convection flare up, but at this point it doesn`t appear to
be too noteworthy of an event. Will have to stay tuned as this is
too far out to have much confidence at this point in how exactly it
will play out.
&&
.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1210 AM CDT FRI MAY 8 2015
Have terminals prevailing VFR with tempo MVFR at TOP/FOE as
showers and thunder may clip the area overnight. Winds become
easterly through the period and next round of convection
approaches late in the TAF period. Will leave for next issuance to
add and refine a time.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Drake/Sanders
AVIATION...67
AREA FORECAST DISCUSSION
NWS JACKSON KY
629 PM EDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 630 PM EDT FRI MAY 8 2015
ISOLATED SHOWERS AND STORMS ARE STILL POPPING UP ACROSS THE
SOUTHERN HALF OF OUR FORECAST AREA SO HAVE KEPT SLIGHT CHANCE POPS
IN THE GRIDS FOR THE NEXT FEW HOURS. OTHERWISE...FORECAST APPEARS
TO BE ON TRACK SO MADE MINOR ADJUSTMENTS TO T AND TD GIRDS TO
ALIGN THEM WITH MOST RECENT OBS. SENT UPDATED GRIDS TO NDFD AND
WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI MAY 8 2015
18Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE HOLDING ON OVER EASTERN
KENTUCKY AND TENNESSEE WHILE LOWER PRESSURE SETTLES DEEPER INTO
THE PLAINS AND MID MISSISSIPPI VALLEY. IN ADDITION...SUB TROPICAL
STORM ANA IS SEEN OFF THE COAST OF SOUTH CAROLINA. WITH LESS
IN THE WAY OF MORNING CLOUD COVER TODAY THE INITIAL STORMS
STARTED EARLIER THAN YESTERDAY...THOUGH SO FAR COVERAGE HAS BEEN
MORE ISOLATED. THEIR SLOW MOVEMENT WILL LEAD TO CONCERNS FOR
HEAVY RAINS AND A POTENTIAL FOR HIGHLY LOCALIZED FLOODING THROUGH
THE FIRST PART OF THE EVENING. OTHERWISE...TEMPERATURES ARE
PEAKING IN THE MID AND UPPER 80S WHILE DEWPOINTS RANGE FROM THE
MID 50S TO LOW 60S ACROSS THE AREA...AMID LIGHT AND VARIABLE
WINDS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE FAIRLY STEADY
STATE PATTERN OVER THE REGION INTO SUNDAY MORNING. THEY ALL
DEPICT A LARGE RIDGE OF MODERATE STRENGTH OVER THE SOUTHEAST THIRD
OF THE NATION. IN THE MIDDLE OF THIS RIDGE IS A COMPACT UPPER LOW
ASSOCIATED WITH ANA...WHILE TO THE WEST A HEALTHY CLOSED LOW
TROUGH IS PROGGED TO ROLL EAST THEN NORTHEAST FROM THE FOUR
CORNERS REGION AND INTO THE HIGH PLAINS. THIS WESTERN TROUGH WILL
OPEN UP A BIT DURING THIS PROCESS ALLOWING WAVES OF ENERGY TO
ESCAPE AND DRIFT INTO THE OHIO VALLEY IN THE BROAD SOUTHWEST
FLOW. THESE BITS MAY SCRAPE CLOSE ENOUGH TO EAST KENTUCKY TO ADD
TO A POTENTIAL FOR CONVECTION...AT TIMES...THROUGH THE SHORT
TERM THOUGH THE DIURNAL CYCLE WILL BE DOMINANT. GIVEN THE MODEL
AGREEMENT FOR OUR AREA HAVE FOLLOWED A GENERAL BLEND WITH
EMPHASIS ON THE HRRR AND NAM12 FOR DETAILS.
SENSIBLE WEATHER WILL CONTINUE THIS PERSISTENT PATTERN WITH THE
ADDITION OF A BETTER POTENTIAL FOR EXCESSIVE RAINS FROM ANY
SCATTERED TO ISOLATED STORMS DUE TO INCREASING PW AND SLOW STORM
MOTION. TEMPERATURES WILL BE FAIRLY UNIFORM...TOO...REACHING THE
MID AND UPPER 80S AGAIN SATURDAY AND IN THE MID 50S TO MID 60S
EACH NIGHT VARYING FROM THE COOLER NORTHEAST VALLEYS TO THE
MILD SOUTHWEST RIDGES. WILL CONTINUE INCLUSION OF PATCHY FOG IN
THE VALLEYS EACH NIGHT TOWARDS DAWN.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD AND
WIND GRIDS INITIALLY...FOLLOWED BY THE SUPERBLEND. DID ENHANCE
THE MIN TEMPS FOR RIDGE AND VALLEY DIFFERENCES TONIGHT AND
SATURDAY NIGHT. AS FOR POPS...ENDED UP MOST SIMILAR TO THE MET
NUMBERS...THOUGH WITH AN EXAGGERATED DIURNAL CURVE THAT KEEPS THE
POPS LOWER DURING THE HEART OF THE NIGHT AND THROUGH THE LATE
MORNING HOURS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI MAY 8 2015
UPPER LEVEL RIDGING WILL CONTINUE TO DOMINATE THE FIRST PART OF
THE EXTENDED FORECAST PERIOD. SUNDAY WILL FEATURE A WAVE OF ENERGY
JUST TO THE EAST AND WARM/MOIST AIR OUT AHEAD. THIS WILL LEAD TO
AFTERNOON SHOWERS AND THUNDERSTORMS FOR SUNDAY. THESE STORMS
HOWEVER WILL HAVE LITTLE UPPER LEVEL SUPPORT WITH LITTLE TO NO
SHEAR...GIVEN THIS THE MAIN THREAT HERE WOULD BE HEAVY RAINFALL
AND QUASISTATIONARY STORMS. THESE STORMS WILL MOSTLY DIE OFF WITH
DAYTIME HEATING. ONCE WE MOVE INTO MONDAY THE UPPER LEVEL TROUGH
WILL NEGATIVELY TILT AND CUTOFF ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY AND GREAT LAKES. THIS WILL USHER IN HEIGHT FALLS AND
HELP SWEEP A COLD FRONT ACROSS THE OHIO VALLEY. THE QUESTION WILL
BE HOW DOES THE LIFT LINE UP WITH THE MODERATELY UNSTABLE
ENVIRONMENT AND BETTER SHEAR. RIGHT NOW THE SETUP WOULD LEAN
TOWARD A SQUALL LINE TYPE MODE...HOWEVER THIS WILL HAVE TO BE
LOOKED AT IN SUBSEQUENT FORECAST UPDATES. DID CONTINUE TO BRING
POPS UP ON MONDAY IN ASSOCIATION WITH PASSING FRONTAL BOUNDARY.
IN THE WAKE OF THE COLD FRONT WILL LEAD TO COOLER AND DRIER
CONDITIONS ACROSS THE REGION TUESDAY INTO MUCH OF THE REST OF THE
EXTENDED. HIGH TEMPERATURES ARE EXPECTED TO BE NEAR TO EVEN BELOW
NORMAL. WINDS WILL START OF OUT OF THE WEST/NORTHWEST TO EAST OVER
THROUGH THE REST OF THE PERIOD...AS HIGH PRESSURE DROPS SOUTHEAST
OF OF THE GREAT LAKES. GUIDANCE SUGGESTS OVERRUNNING PRECIP WILL
COME BACK INTO THE PICTURE AS WE MOVE TOWARD FRIDAY. RIGHT NOW
FORECAST SOUNDINGS WOULD SUGGEST LACK OF THUNDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 245 PM EDT FRI MAY 8 2015
CONDITIONS WILL REMAIN GENERALLY VFR THROUGH THE AVIATION PERIOD.
AN EXCEPTION BEING A VERY SMALL CHANCE FOR A THUNDERSTORM AT THE
TAF SITES THIS AFTERNOON AND AGAIN SATURDAY AFTERNOON WHICH WILL
BE KEPT OUT OF THE OFFICIAL TAFS. IN ADDITION THERE IS THE
POTENTIAL FOR SOME MVFR FOG AT THE LOZ AND SME SITES TOWARD DAWN
SATURDAY WHICH HAVE BEEN ADDED TO THOSE TAFS AS A TEMPO GROUP.
WINDS WILL REMAIN MAINLY LIGHT AND VARIABLE THROUGH THE BULK OF
THE PERIOD BEFORE TURNING TO THE SOUTHWEST AND INCREASING FROM THE
SOUTHWEST BY MIDDAY SATURDAY IN THE SOUTHWEST PARTS OF THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
255 PM CDT FRI MAY 8 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 158
PM CDT FRI MAY 8 2015
SHOWERS AND THUNDERSTORMS...MANY ASSOCIATED WITH AN MCV IN
SOUTHEAST MISSOURI...WILL CONTINUE TO PUSH ACROSS THE AREA THIS
AFTERNOON. HRRR MODEL HANDLED THIS SITUATION VERY WELL AND WILL BE
FOLLOWED INTO THE NIGHTTIME HOURS. THE MCV MAY ASSIST IN AIDING
STORMS TO PRODUCE ISOLATED SEVERE WIND GUSTS THIS AFTERNOON.
GFS SEEMS TO HAVE A DECENT AND CONSISTENT HANDLE ON THINGS OVER
THE NEXT COUPLE OF DAYS. ECMWF IS SIMILAR IN CHARACTER. AFTER THE
MAIN ROUND THIS AFTERNOON...ONLY SCATTERED CONVECTION EXPECTED
UNTIL LATER SATURDAY MORNING WHEN THE NEXT PIECE OF ENERGY MOVES
INTO SEMO. HOWEVER...LOOKS LIKE MOST OF THAT WILL MOVE MORE INTO
ILLINOIS AND POSSIBLY SOUTHWEST INDIANA.
A LULL THEN SETS IN FOR SATURDAY NIGHT INTO SUNDAY WITH SOME
SCATTERED STORMS POSSIBLE. CAP IS NEVER TOO STRONG DURING THIS
PERIOD. LATE SUNDAY NIGHT THE MAIN TROUGH BEGINS TO LIFT OUT AND
WILL BRING A BETTER STORM COVERAGE INTO SOUTHEAST MISSOURI.
SEVERE CHANCES ARE SOMEWHAT LIMITED THROUGH THIS PERIOD. ISOLATED
SEVERE IS POSSIBLE DURING THE AFTERNOON AND EVENINGS BUT ORGANIZED
SEVERE WEATHER IS NOT EXPECTED.
.LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 158 PM CDT MAY 8
2015
THE BEGINNING OF THE EXTENDED PERIOD WILL START WITH THE PASSAGE OF
A COLD FRONT THROUGH THE PAH FORECAST AREA...TRAILING FROM A CYCLONE
MOVING INTO THE GREAT LAKES REGION. THIS SHOULD RESULT IN RAPID
CESSATION OF PCPN (SHOWERS/TSTMS) BY EVENING WEST TO EAST ACROSS OUR
REGION...AND A TURN OF THE LOW LEVEL WINDS TO THE WEST.
UNDER QUASI-ZONAL FLOW ALOFT...AND A RIDGE OF HIGH SFC PRESSURE...
MOST OF THE PAH FORECAST AREA SHOULD BE RAIN-FREE THROUGH WED...
EXCEPT PERHAPS THE FAR WEST. FROM MID WEEK ON...THE 00Z ECMWF SEEMED
TO BE THE ODD MODEL OUT...IN DISAGREEMENT WITH ITS ENSEMBLE MEAN
(AND THE GEFS/NAEFS). IT SHOWED A TENDENCY TOWARD A QUICKER RETURN
FLOW DUE TO EXTRA MID LEVEL SHRTWV ENERGY TO THE SE OF A WRN CONUS
TROF. THE 12Z RUN CAME IN LOOKING QUITE SIMILAR TO THE MORE
CONSISTENT GFS...WHICH SHOWED MORE OF AN ERLY LOW LEVEL FLOW AND
DRIER CONDITIONS INTO PART OF THU. THUS...A SLOW RAMPING UP OF
(LIMITED) POPS FROM WEST TO EAST WAS LEFT IN THE FORECAST WED
NIGHT/THU/THU NIGHT. BY FRI...PCPN SEEMS A BIT MORE PROBABLE WITH A
SFC WARM FRONT SOMEWHERE IN THE VICINITY. OVERALL...CONFIDENCE IN
WHERE AND WHEN IT WILL BE RAINING FROM MID WEEK ON IS IFFY.
TEMPS DURING THE EXTENDED PERIOD CAN BE EXPECTED TO BE NEAR
SEASONABLE LEVELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1224 PM CDT FRI MAY 8 2015
ON-GOING CONVECTION OVER SOUTHEAST MISSOURI IS EXPECTED TO MOVE
EASTWARD AND AFFECT KPAH AND KEVV BUT SHOULD WEAKEN BY KOWB. MVFR
CONDITIONS IN STORMS. MAIN WAVE WILL PASS THROUGH THE AREA BY
EARLY EVENING WITH ISOLATED/SCATTERED CONVECTION OVERNIGHT.
TOWARDS DAYBREAK EXPECT IFR CONDITIONS AT SEVERAL SITES WITH
LINGERING LOW LEVEL MOISTURE IN THE AREA.PS
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...PS
LONG TERM...DB
AVIATION...PS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
353 PM EDT FRI MAY 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI MAY 8 2015
18Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE HOLDING ON OVER EASTERN
KENTUCKY AND TENNESSEE WHILE LOWER PRESSURE SETTLES DEEPER INTO
THE PLAINS AND MID MISSISSIPPI VALLEY. IN ADDITION...SUB TROPICAL
STORM ANA IS SEEN OFF THE COAST OF SOUTH CAROLINA. WITH LESS
IN THE WAY OF MORNING CLOUD COVER TODAY THE INITIAL STORMS
STARTED EARLIER THAN YESTERDAY...THOUGH SO FAR COVERAGE HAS BEEN
MORE ISOLATED. THEIR SLOW MOVEMENT WILL LEAD TO CONCERNS FOR
HEAVY RAINS AND A POTENTIAL FOR HIGHLY LOCALIZED FLOODING THROUGH
THE FIRST PART OF THE EVENING. OTHERWISE...TEMPERATURES ARE
PEAKING IN THE MID AND UPPER 80S WHILE DEWPOINTS RANGE FROM THE
MID 50S TO LOW 60S ACROSS THE AREA...AMID LIGHT AND VARIABLE
WINDS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE FAIRLY STEADY
STATE PATTERN OVER THE REGION INTO SUNDAY MORNING. THEY ALL
DEPICT A LARGE RIDGE OF MODERATE STRENGTH OVER THE SOUTHEAST THIRD
OF THE NATION. IN THE MIDDLE OF THIS RIDGE IS A COMPACT UPPER LOW
ASSOCIATED WITH ANA...WHILE TO THE WEST A HEALTHY CLOSED LOW
TROUGH IS PROGGED TO ROLL EAST THEN NORTHEAST FROM THE FOUR
CORNERS REGION AND INTO THE HIGH PLAINS. THIS WESTERN TROUGH WILL
OPEN UP A BIT DURING THIS PROCESS ALLOWING WAVES OF ENERGY TO
ESCAPE AND DRIFT INTO THE OHIO VALLEY IN THE BROAD SOUTHWEST
FLOW. THESE BITS MAY SCRAPE CLOSE ENOUGH TO EAST KENTUCKY TO ADD
TO A POTENTIAL FOR CONVECTION...AT TIMES...THROUGH THE SHORT
TERM THOUGH THE DIURNAL CYCLE WILL BE DOMINANT. GIVEN THE MODEL
AGREEMENT FOR OUR AREA HAVE FOLLOWED A GENERAL BLEND WITH
EMPHASIS ON THE HRRR AND NAM12 FOR DETAILS.
SENSIBLE WEATHER WILL CONTINUE THIS PERSISTENT PATTERN WITH THE
ADDITION OF A BETTER POTENTIAL FOR EXCESSIVE RAINS FROM ANY
SCATTERED TO ISOLATED STORMS DUE TO INCREASING PW AND SLOW STORM
MOTION. TEMPERATURES WILL BE FAIRLY UNIFORM...TOO...REACHING THE
MID AND UPPER 80S AGAIN SATURDAY AND IN THE MID 50S TO MID 60S
EACH NIGHT VARYING FROM THE COOLER NORTHEAST VALLEYS TO THE
MILD SOUTHWEST RIDGES. WILL CONTINUE INCLUSION OF PATCHY FOG IN
THE VALLEYS EACH NIGHT TOWARDS DAWN.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD AND
WIND GRIDS INITIALLY...FOLLOWED BY THE SUPERBLEND. DID ENHANCE
THE MIN TEMPS FOR RIDGE AND VALLEY DIFFERENCES TONIGHT AND
SATURDAY NIGHT. AS FOR POPS...ENDED UP MOST SIMILAR TO THE MET
NUMBERS...THOUGH WITH AN EXAGGERATED DIURNAL CURVE THAT KEEPS THE
POPS LOWER DURING THE HEART OF THE NIGHT AND THROUGH THE LATE
MORNING HOURS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI MAY 8 2015
UPPER LEVEL RIDGING WILL CONTINUE TO DOMINATE THE FIRST PART OF
THE EXTENDED FORECAST PERIOD. SUNDAY WILL FEATURE A WAVE OF ENERGY
JUST TO THE EAST AND WARM/MOIST AIR OUT AHEAD. THIS WILL LEAD TO
AFTERNOON SHOWERS AND THUNDERSTORMS FOR SUNDAY. THESE STORMS
HOWEVER WILL HAVE LITTLE UPPER LEVEL SUPPORT WITH LITTLE TO NO
SHEAR...GIVEN THIS THE MAIN THREAT HERE WOULD BE HEAVY RAINFALL
AND QUASISTATIONARY STORMS. THESE STORMS WILL MOSTLY DIE OFF WITH
DAYTIME HEATING. ONCE WE MOVE INTO MONDAY THE UPPER LEVEL TROUGH
WILL NEGATIVELY TILT AND CUTOFF ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY AND GREAT LAKES. THIS WILL USHER IN HEIGHT FALLS AND
HELP SWEEP A COLD FRONT ACROSS THE OHIO VALLEY. THE QUESTION WILL
BE HOW DOES THE LIFT LINE UP WITH THE MODERATELY UNSTABLE
ENVIRONMENT AND BETTER SHEAR. RIGHT NOW THE SETUP WOULD LEAN
TOWARD A SQUALL LINE TYPE MODE...HOWEVER THIS WILL HAVE TO BE
LOOKED AT IN SUBSEQUENT FORECAST UPDATES. DID CONTINUE TO BRING
POPS UP ON MONDAY IN ASSOCIATION WITH PASSING FRONTAL BOUNDARY.
IN THE WAKE OF THE COLD FRONT WILL LEAD TO COOLER AND DRIER
CONDITIONS ACROSS THE REGION TUESDAY INTO MUCH OF THE REST OF THE
EXTENDED. HIGH TEMPERATURES ARE EXPECTED TO BE NEAR TO EVEN BELOW
NORMAL. WINDS WILL START OF OUT OF THE WEST/NORTHWEST TO EAST OVER
THROUGH THE REST OF THE PERIOD...AS HIGH PRESSURE DROPS SOUTHEAST
OF OF THE GREAT LAKES. GUIDANCE SUGGESTS OVERRUNNING PRECIP WILL
COME BACK INTO THE PICTURE AS WE MOVE TOWARD FRIDAY. RIGHT NOW
FORECAST SOUNDINGS WOULD SUGGEST LACK OF THUNDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 245 PM EDT FRI MAY 8 2015
CONDITIONS WILL REMAIN GENERALLY VFR THROUGH THE AVIATION PERIOD.
AN EXCEPTION BEING A VERY SMALL CHANCE FOR A THUNDERSTORM AT THE
TAF SITES THIS AFTERNOON AND AGAIN SATURDAY AFTERNOON WHICH WILL
BE KEPT OUT OF THE OFFICIAL TAFS. IN ADDITION THERE IS THE
POTENTIAL FOR SOME MVFR FOG AT THE LOZ AND SME SITES TOWARD DAWN
SATURDAY WHICH HAVE BEEN ADDED TO THOSE TAFS AS A TEMPO GROUP.
WINDS WILL REMAIN MAINLY LIGHT AND VARIABLE THROUGH THE BULK OF
THE PERIOD BEFORE TURNING TO THE SOUTHWEST AND INCREASING FROM THE
SOUTHWEST BY MIDDAY SATURDAY IN THE SOUTHWEST PARTS OF THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1228 PM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 1224 PM CDT FRI MAY 8 2015
UPDATED AVIATION SECTION FOR 18Z TAFS
UPDATE ISSUED AT 923 AM CDT FRI MAY 8 2015
ADJUSTED GRIDS/FORECAST TO BE CLOSER TO HRRR MODEL OUTPUT. HRRR
HAS BEEN VERY CONSISTENT THE LAST FEW RUNS ON PUSHING THE PRECIP
TO OUR WEST THROUGH MOST OF THE CWA TODAY. AM CONCERNED ABOUT MCV
SEEN IN THE RADAR LOOPS OVER NORTH CENTRAL ARKANSAS. SEEMS TO BE
LIFTING A BIT NORTHEAST AND MAY ENHANCE PRECIPITATION OVER
SOUTHEAST MISSOURI LATER THIS MORNING INTO THE AFTERNOON. WILL BE
KEEPING A CLOSE EYE ON IT.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 315 AM CDT FRI MAY 8 2015
THE MODELS ARE IN GOOD AGREEMENT ON THE OVERALL SYNOPTIC PATTERN
THROUGH THE UPCOMING WEEKEND. OUR REGION WILL BE ON THE EASTERN
PERIPHERY OF DEEP-LAYER SOUTHWEST FLOW IN ADVANCE OF A CLOSED LOW.
THE DEEP 500 MB CLOSED LOW WILL EJECT NORTHEAST FROM THE DESERT
SOUTHWEST INTO THE UPPER MISSOURI VALLEY BY SUNDAY EVENING. PLENTY
OF MOISTURE WILL BE IN PLACE...WITH PRECIP WATER VALUES REMAINING
IN THE 1.5 TO 1.8 INCH RANGE. A SERIES OF IMPULSES EMBEDDED IN THE
SOUTHWESTERLY FLOW WILL BRING CLOUDS AND SCATTERED SHOWERS AND
STORMS. THE SMALLEST PRECIP CHANCES WILL BE OVER PARTS OF WESTERN
KENTUCKY...WHICH WILL BE ON THE PERIPHERY OF THE MID-LEVEL SOUTHWEST
FLOW AND ASSOCIATED IMPULSES.
THE FIRST IN THE SERIES OF IMPULSES IS RESPONSIBLE FOR WIDESPREAD
SHOWERS AND STORMS OVER FAR WESTERN MISSOURI AND ARKANSAS EARLY
THIS MORNING. MOST OF THE MODELS ARE BRINGING THIS PRECIP EASTWARD
TOO RAPIDLY THIS MORNING. THE SLOWER 00Z ECMWF LOOKS
REASONABLE...TAKING THE LEADING EDGE OF SHOWERS INTO SE MISSOURI
AND SRN ILLINOIS LATER THIS MORNING...AND THEN INTO THE LOWER OHIO
VALLEY THIS AFTERNOON. THE MODELS ARE NOT SHOWING AS MUCH
INSTABILITY AS THEY DID IN PREVIOUS RUNS...BUT STILL MORE THAN
ENOUGH FOR THUNDER. THERE WILL BE A FAIRLY STRONG GRADIENT OF POPS
TODAY...RANGING FROM SLIGHT CHANCE IN THE KHOP AREA TO LIKELY IN
THE KMVN/KMDH/KPOF CORRIDOR. HIGH TEMPS WILL BE SIMILAR TO
THURSDAY...EXCEPT A LITTLE COOLER IN THE AREA OF LIKELY POPS.
THERE WILL BE A BIT OF A LULL IN THE PRECIP TONIGHT IN THE WAKE OF
THE FIRST IMPULSE.
ON SATURDAY...PRECIP CHANCES WILL AGAIN RAMP UP INTO THE LIKELY
CATEGORY IN PARTS OF OUR REGION AS A SECOND IMPULSE LIFTS
NORTHEAST. THE LOWEST CHANCES WILL REMAIN IN THE KHOP AREA...WHICH
WILL BE ON THE FRINGE OF THE ACTIVE FLOW PATTERN. INSTABILITY IS
ONCE AGAIN NOT AS STRONG AS THE MODELS PREVIOUSLY INDICATED...BUT
THUNDER IS STILL LIKELY. HIGH TEMPS WILL DEPEND ON THE DURATION OF
PRECIP AND CLOUD COVER...WHICH IS A CHALLENGE TO ESTIMATE. GIVEN
THE WARM START TO THE DAY AND WARM 850 MB TEMPS NEAR 14...IT WONT
TAKE MUCH SUN TO REACH THE LOWER AND MID 80S.
ANOTHER RELATIVE LULL IN THE PRECIP IS EXPECTED SATURDAY NIGHT IN
THE WAKE OF THE SECOND IMPULSE.
SUNDAY MAY BE THE WARMEST AND DRIEST PERIOD OF THE
WEEKEND...DEPENDING ON THE MOTION OF SUB-TROPICAL STORM ANA OFF
THE CAROLINA COAST. THE 500 MB RIDGE OVER THE TENNESSEE VALLEY IS
FORECAST TO SHARPEN SOMEWHAT IN RESPONSE TO ANA...AND IT MAY
RETROGRADE A BIT WESTWARD. EVEN IF THIS TAKES PLACE...SOME
DIURNALLY INDUCED CONVECTION WOULD OCCUR GIVEN THE STRONGER SOLAR
HEATING AND RESULTANT INSTABILITY. WILL KEEP POPS IN THE CHANCE
CATEGORY. HIGHS WILL BE SIMILAR TO THE PREVIOUS FEW DAYS.
THE THIRD AND STRONGEST SHORTWAVE IN THE SERIES WILL EJECT
NORTHEAST ACROSS THE PLAINS SUNDAY NIGHT. SHOWERS AND STORMS WILL
LIKELY SPREAD EASTWARD INTO THE MID MISSISSIPPI VALLEY LATE AT
NIGHT.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI MAY 8 2015
FAIRLY HIGH CONFIDENCE THROUGH TUESDAY...BUT THEN VERY LOW
CONFIDENCE FOR WEDNESDAY THROUGH FRIDAY.
THE 00Z MODELS DEVELOP A LARGE SWATH OF HEAVY RAINFALL FROM WESTERN
ARKANSAS THROUGH CENTRAL MISSOURI OVERNIGHT SUNDAY NIGHT. THEY
FIZZLE THIS CONVECTION OUT MONDAY MORNING AS IT MOVES INTO SOUTHEAST
MISSOURI AND SOUTHERN ILLINOIS...AND THEY ARE LESS THAN ROBUST WITH
CONVECTIVE DEVELOPMENT OVER OUR REGION IN THE AFTERNOON. THEY DO
AGREE IN KEEPING THE AREA DRY MONDAY NIGHT INTO TUESDAY.
WILL CONTINUE WITH THE LIKELY POPS AREAWIDE ON MONDAY WITH AN
EMPHASIS IN THE WEST/NORTHWEST...AND WILL KEEP SLIGHT CHANCES OVER
MUCH OF THE AREA INTO MONDAY EVENING. GIVEN THE UNFAVORABLE TIMING
OF THE MAIN AREA OF CONVECTION INTO THE REGION...AM LESS CONCERNED
WITH SEVERE WEATHER POTENTIAL ON MONDAY.
REALLY LIKE THE 00Z GFS WHICH HAS BEEN MOST CONSISTENT HEADING
THROUGH THE SECOND HALF OF NEXT WEEK. IT HAS PERSISTENT TROUGHING
OFF THE WEST COAST AND OVER THE GREAT LAKES/NORTHEAST...WITH A RIDGE
OVER THE ROCKIES/PLAINS. THIS RESULTS IN DRY SURFACE HIGH PRESSURE
OVER OUR REGION THROUGH THE PERIOD. THE 00Z GFS ENSEMBLE MEAN
SUPPORTS THE 00Z GFS OPERATIONAL RUN.
THE 00Z ECMWF HAS LESS TROUGHING IN THE GREAT LAKES/NORTHEAST AND
REALLY FLATTENS THE RIDGE...PUTTING OUR AREA BACK INTO SOUTHWEST
FLOW ALOFT BY 12Z WEDNESDAY. OF COURSE WITH A DEPARTING SURFACE
HIGH...MOISTURE AND QPF FOLLOW QUICKLY AND PERSIST THROUGH THE END
OF THE WEEK.
WOULD PREFER TO HAVE A DRY FORECAST WEDNESDAY THROUGH FRIDAY...BUT
WILL HAVE TO KEEP POPS IN UNTIL THE ECMWF SHOWS SOME SIGN OF COMING
INTO LINE WITH THE GFS. TEMPERATURES WILL START OUT ABOVE NORMAL ON
MONDAY AND THEN QUICKLY DROP A FEW TICKS BELOW NORMAL FOR THE
REMAINDER OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1224 PM CDT FRI MAY 8 2015
ON-GOING CONVECTION OVER SOUTHEAST MISSOURI IS EXPECTED TO MOVE
EASTWARD AND AFFECT KPAH AND KEVV BUT SHOULD WEAKEN BY KOWB. MVFR
CONDITIONS IN STORMS. MAIN WAVE WILL PASS THROUGH THE AREA BY
EARLY EVENING WITH ISOLATED/SCATTERED CONVECTION OVERNIGHT.
TOWARDS DAYBREAK EXPECT IFR CONDITIONS AT SEVERAL SITES WITH
LINGERING LOW LEVEL MOISTURE IN THE AREA.PS
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...PS
SHORT TERM...MY
LONG TERM...DRS
AVIATION...PS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
927 AM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 923 AM CDT FRI MAY 8 2015
ADJUSTED GRIDS/FORECAST TO BE CLOSER TO HRRR MODEL OUTPUT. HRRR
HAS BEEN VERY CONSISTENT THE LAST FEW RUNS ON PUSHING THE PRECIP
TO OUR WEST THROUGH MOST OF THE CWA TODAY. AM CONCERNED ABOUT MCV
SEEN IN THE RADAR LOOPS OVER NORTH CENTRAL ARKANSAS. SEEMS TO BE
LIFTING A BIT NORTHEAST AND MAY ENHANCE PRECIPITATION OVER
SOUTHEAST MISSOURI LATER THIS MORNING INTO THE AFTERNOON. WILL BE
KEEPING A CLOSE EYE ON IT.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 315 AM CDT FRI MAY 8 2015
THE MODELS ARE IN GOOD AGREEMENT ON THE OVERALL SYNOPTIC PATTERN
THROUGH THE UPCOMING WEEKEND. OUR REGION WILL BE ON THE EASTERN
PERIPHERY OF DEEP-LAYER SOUTHWEST FLOW IN ADVANCE OF A CLOSED LOW.
THE DEEP 500 MB CLOSED LOW WILL EJECT NORTHEAST FROM THE DESERT
SOUTHWEST INTO THE UPPER MISSOURI VALLEY BY SUNDAY EVENING. PLENTY
OF MOISTURE WILL BE IN PLACE...WITH PRECIP WATER VALUES REMAINING
IN THE 1.5 TO 1.8 INCH RANGE. A SERIES OF IMPULSES EMBEDDED IN THE
SOUTHWESTERLY FLOW WILL BRING CLOUDS AND SCATTERED SHOWERS AND
STORMS. THE SMALLEST PRECIP CHANCES WILL BE OVER PARTS OF WESTERN
KENTUCKY...WHICH WILL BE ON THE PERIPHERY OF THE MID-LEVEL SOUTHWEST
FLOW AND ASSOCIATED IMPULSES.
THE FIRST IN THE SERIES OF IMPULSES IS RESPONSIBLE FOR WIDESPREAD
SHOWERS AND STORMS OVER FAR WESTERN MISSOURI AND ARKANSAS EARLY
THIS MORNING. MOST OF THE MODELS ARE BRINGING THIS PRECIP EASTWARD
TOO RAPIDLY THIS MORNING. THE SLOWER 00Z ECMWF LOOKS
REASONABLE...TAKING THE LEADING EDGE OF SHOWERS INTO SE MISSOURI
AND SRN ILLINOIS LATER THIS MORNING...AND THEN INTO THE LOWER OHIO
VALLEY THIS AFTERNOON. THE MODELS ARE NOT SHOWING AS MUCH
INSTABILITY AS THEY DID IN PREVIOUS RUNS...BUT STILL MORE THAN
ENOUGH FOR THUNDER. THERE WILL BE A FAIRLY STRONG GRADIENT OF POPS
TODAY...RANGING FROM SLIGHT CHANCE IN THE KHOP AREA TO LIKELY IN
THE KMVN/KMDH/KPOF CORRIDOR. HIGH TEMPS WILL BE SIMILAR TO
THURSDAY...EXCEPT A LITTLE COOLER IN THE AREA OF LIKELY POPS.
THERE WILL BE A BIT OF A LULL IN THE PRECIP TONIGHT IN THE WAKE OF
THE FIRST IMPULSE.
ON SATURDAY...PRECIP CHANCES WILL AGAIN RAMP UP INTO THE LIKELY
CATEGORY IN PARTS OF OUR REGION AS A SECOND IMPULSE LIFTS
NORTHEAST. THE LOWEST CHANCES WILL REMAIN IN THE KHOP AREA...WHICH
WILL BE ON THE FRINGE OF THE ACTIVE FLOW PATTERN. INSTABILITY IS
ONCE AGAIN NOT AS STRONG AS THE MODELS PREVIOUSLY INDICATED...BUT
THUNDER IS STILL LIKELY. HIGH TEMPS WILL DEPEND ON THE DURATION OF
PRECIP AND CLOUD COVER...WHICH IS A CHALLENGE TO ESTIMATE. GIVEN
THE WARM START TO THE DAY AND WARM 850 MB TEMPS NEAR 14...IT WONT
TAKE MUCH SUN TO REACH THE LOWER AND MID 80S.
ANOTHER RELATIVE LULL IN THE PRECIP IS EXPECTED SATURDAY NIGHT IN
THE WAKE OF THE SECOND IMPULSE.
SUNDAY MAY BE THE WARMEST AND DRIEST PERIOD OF THE
WEEKEND...DEPENDING ON THE MOTION OF SUB-TROPICAL STORM ANA OFF
THE CAROLINA COAST. THE 500 MB RIDGE OVER THE TENNESSEE VALLEY IS
FORECAST TO SHARPEN SOMEWHAT IN RESPONSE TO ANA...AND IT MAY
RETROGRADE A BIT WESTWARD. EVEN IF THIS TAKES PLACE...SOME
DIURNALLY INDUCED CONVECTION WOULD OCCUR GIVEN THE STRONGER SOLAR
HEATING AND RESULTANT INSTABILITY. WILL KEEP POPS IN THE CHANCE
CATEGORY. HIGHS WILL BE SIMILAR TO THE PREVIOUS FEW DAYS.
THE THIRD AND STRONGEST SHORTWAVE IN THE SERIES WILL EJECT
NORTHEAST ACROSS THE PLAINS SUNDAY NIGHT. SHOWERS AND STORMS WILL
LIKELY SPREAD EASTWARD INTO THE MID MISSISSIPPI VALLEY LATE AT
NIGHT.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI MAY 8 2015
FAIRLY HIGH CONFIDENCE THROUGH TUESDAY...BUT THEN VERY LOW
CONFIDENCE FOR WEDNESDAY THROUGH FRIDAY.
THE 00Z MODELS DEVELOP A LARGE SWATH OF HEAVY RAINFALL FROM WESTERN
ARKANSAS THROUGH CENTRAL MISSOURI OVERNIGHT SUNDAY NIGHT. THEY
FIZZLE THIS CONVECTION OUT MONDAY MORNING AS IT MOVES INTO SOUTHEAST
MISSOURI AND SOUTHERN ILLINOIS...AND THEY ARE LESS THAN ROBUST WITH
CONVECTIVE DEVELOPMENT OVER OUR REGION IN THE AFTERNOON. THEY DO
AGREE IN KEEPING THE AREA DRY MONDAY NIGHT INTO TUESDAY.
WILL CONTINUE WITH THE LIKELY POPS AREAWIDE ON MONDAY WITH AN
EMPHASIS IN THE WEST/NORTHWEST...AND WILL KEEP SLIGHT CHANCES OVER
MUCH OF THE AREA INTO MONDAY EVENING. GIVEN THE UNFAVORABLE TIMING
OF THE MAIN AREA OF CONVECTION INTO THE REGION...AM LESS CONCERNED
WITH SEVERE WEATHER POTENTIAL ON MONDAY.
REALLY LIKE THE 00Z GFS WHICH HAS BEEN MOST CONSISTENT HEADING
THROUGH THE SECOND HALF OF NEXT WEEK. IT HAS PERSISTENT TROUGHING
OFF THE WEST COAST AND OVER THE GREAT LAKES/NORTHEAST...WITH A RIDGE
OVER THE ROCKIES/PLAINS. THIS RESULTS IN DRY SURFACE HIGH PRESSURE
OVER OUR REGION THROUGH THE PERIOD. THE 00Z GFS ENSEMBLE MEAN
SUPPORTS THE 00Z GFS OPERATIONAL RUN.
THE 00Z ECMWF HAS LESS TROUGHING IN THE GREAT LAKES/NORTHEAST AND
REALLY FLATTENS THE RIDGE...PUTTING OUR AREA BACK INTO SOUTHWEST
FLOW ALOFT BY 12Z WEDNESDAY. OF COURSE WITH A DEPARTING SURFACE
HIGH...MOISTURE AND QPF FOLLOW QUICKLY AND PERSIST THROUGH THE END
OF THE WEEK.
WOULD PREFER TO HAVE A DRY FORECAST WEDNESDAY THROUGH FRIDAY...BUT
WILL HAVE TO KEEP POPS IN UNTIL THE ECMWF SHOWS SOME SIGN OF COMING
INTO LINE WITH THE GFS. TEMPERATURES WILL START OUT ABOVE NORMAL ON
MONDAY AND THEN QUICKLY DROP A FEW TICKS BELOW NORMAL FOR THE
REMAINDER OF THE WEEK.
&&
.AVIATION...
ISSUED AT 630 AM CDT FRI MAY 8 2015
MID AND HIGH LEVEL CLOUDINESS WILL INCREASE THIS MORNING...ALONG
WITH DIURNAL HIGH-BASED CUMULUS CLOUDS. SCATTERED SHOWERS AND STORMS
WILL SPREAD EASTWARD ACROSS THE TAF SITES DURING THE MIDDAY AND
AFTERNOON HOURS. SOME LOCAL MVFR CONDITIONS ARE EXPECTED IN STORMS.
THE STORMS SHOULD END EARLY THIS EVENING AS AN UPPER LEVEL
DISTURBANCE MOVES PAST OUR AREA AND NOCTURNAL STABILIZATION TAKES
PLACE.
MID LEVEL CIGS ARE EXPECTED OVERNIGHT. DUE TO HIGHER DEW
POINTS...LIGHT WINDS...AND POSSIBLY RAIN-MOISTENED GROUND...SOME
MVFR FOG IS LIKELY AROUND SUNRISE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...PS
SHORT TERM...MY
LONG TERM...DRS
AVIATION...MY
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
132 PM CDT FRI MAY 8 2015
.AVIATION...
FOR THE 24 HOUR TAF PERIOD ENDING 09/18Z...TSTMS AND CIGS WILL
CONTINUE TO BE THE MAIN CONCERNS. FOR THIS AFTERNOON...SCATTERED
SHOWERS AND TSTMS WILL BE MOVING NORTHEAST ACROSS THE REGION.
EXPECT BRIEF VSBY AND CIG REDUCTIONS TO MVFR VCNTY OF THE
CONVECTION AS WELL AS MODERATE TURBULENCE AND SFC WIND GUST UP TO
30 KTS PSBL IN THE STRONGEST STORMS. WIDESPREAD MVFR CIGS WILL
RETURN AFTER MIDNIGHT AND PREVAIL THROUGH MUCH OF SATURDAY
MORNING. ALSO...ADDITIONAL SHWRS AND TSTMS WILL SPREAD INTO THE
AREA FROM THE WEST...BRINGING PERIODS OF IFR BETWEEN 06Z AND 14Z.
VFR EXPECTED TO RETURN BY 18Z SATURDAY...BUT SCATTERED CONVECTION
WILL ONCE AGAIN DEVELOP. /14/
&&
.PREV DISCUSSION... /ISSUED 1106 AM CDT FRI MAY 8 2015/
DISCUSSION...
SCATTERED CONVECTION CONTINUES TO LINGER ACROSS PARTS OF THE
REGION THIS MORNING...AND THIS WILL LIKELY BE THE WAY OF IT FOR
THE REMAINDER OF THE DAY. DAYTIME HEATING IS EXPECTED TO CONTRIBUTE
TO REDEVELOPMENT THIS AFTERNOON. THE NORTHWESTERN HALF OF OUR
REGION IS UNDER A SLIGHT RISK FOR SEVERE THUNDERSTORMS...AND THE
PRIMARY THREATS WITH ANY STORMS WILL BE DAMAGING WINDS AND HEAVY
RAINFALL. THE FLOODING THREAT WILL BE FAR MORE ENHANCED OVER THE
AREAS THAT RECEIVED HEAVY RAINFALL OVERNIGHT AND THIS MORNING. FOR
THE UPDATE...HAVE MADE SOME MINOR ADJUSTMENTS TO POPS/WX/QPF...BUT
OTHERWISE...THE FCST IS IN GOOD SHAPE. /12/
PREV DISCUSSION... /ISSUED 830 AM CDT FRI MAY 8 2015/
DISCUSSION...
WHAT IS LEFT OF THE OVERNIGHT MCS CONTINUES TO MOVE EASTWARD JUST
NORTH OF I-20 IN EXTREME EAST TEXAS AND NORTHERN LOUISIANA WITH
SCATTERED CONVECTION REDEVELOPING FARTHER NORTHWEST. TWO CELLS OF
PRIMARY CONCERN. THE FIRST IS WHAT USED TO BE THE SWRN END OF THE
MCS...WHICH IS JUST EAST OF MINDEN LA AS OF 13Z.
THE SECOND STORM IS MOVING INTO CADDO PARISH AND OUT OF E TX.
EXTREMELY HEAVY RAINFALL OCCURRED EARLIER OVER HARRISON COUNTY. 6
INCHES OF RAIN WAS MEASURED NORTH OF HALLSVILLE AND CONSIDERABLE
FLASH FLOODING WAS ALSO REPORTED. THIS CELL IS DISSIPATING AS IT
MOVES INTO AIR THAT HAS BEEN SOMEWHAT STABILIZED BY COOL OUTFLOW
FROM THE OLD MCS TO THE EAST.
HAVE UPDATED POP/QPF/WX GRIDS THROUGH 18Z. /09/
PREV DISCUSSION... /ISSUED 445 AM CDT FRI MAY 8 2015/
CORRECTED TO INCLUDE AVIATION DISCUSSION...
DISCUSSION...
MCS CONTINUES TO MARCH EASTWARD BUT IS ALSO GRADUALLY WEAKENING.
LATEST HRRR HAS HANDLED THE CONVECTION QUITE WELL TONIGHT WITH THE
EXCEPTION OF BEING TOO SLOW. RADAR TRENDS ALSO PROMOTE HIGHER
CONFIDENCE IN THE HRRR IN REGARDS TO THE CONVECTION MOVING ACROSS
THE REMAINDER OF OUR NRN LA PARISHES/SRN AR COUNTIES NORTH OF
I-20 WHICH SHOULD OCCUR AROUND 12-14Z BASED ON CURRENT SPEEDS.
HAVE ONCE INCLUDED PRE-FIRST PERIOD WORDING TO HANDLE POPS PRIOR
TO 12Z THIS MORNING. WILL LIKELY SEND A ZFP UPDATE AFTER THAT TIME
TO CLEAN UP THE TEXT.
WITH THE MCS EXPECTED TO EXIT THE AREA EARLY IN THE
MORNING...LOCATIONS AFFECTED BY THE RAIN THIS MORNING SHOULD HAVE
PLENTY OF TIME TO RECOVER. RESIDUAL OUTFLOW BOUNDARIES COMBINED
WITH SEA BREEZE ACTIVITY SHOULD ONCE AGAIN LEAD TO ISOLATED TO
WIDELY SCATTERED CONVECTION BY EARLY AFTERNOON. YET ANOTHER MCS IS
EXPECTED TO DEVELOP UPSTREAM ACROSS SRN OK SOUTHWARD INTO TX. THE
NAM HAS CONSISTENTLY BEEN TOO FAST OVER THE LAST SEVERAL DAYS WITH
MOVING CONVECTION INTO THE ARKLATEX. HOWEVER...OTHER MODELS ALSO
INDICATE SHWRS/TSTMS MOVING INTO AREAS NW OF A TYLER TO PRESCOTT
LINE PRIOR TO 09/06Z SO HAVE INCLUDED LIKELY POPS BEGINNING THIS
EVENING. A SEVERE WEATHER THREAT IS IN PLAY MAINLY IN THE FORM OF
DAMAGING WINDS.
SATURDAY`S FORECAST IS PRETTY MUCH A REPEAT OF TODAY. ONE ROUND OF
CONVECTION SHOULD END DURING THE MORNING FOLLOWED BY ANOTHER
STRONG TO SEVERE CONVECTIVE COMPLEX DURING THE LATE AFTERNOON AND
INTO THE OVERNIGHT HRS. POPS WILL CONTINUE TO INCREASE GOING INTO
SUNDAY AND MONDAY AS LARGE SCALE ASCENT SPREADS OVER THE AREA IN
RESPONSE TO AN UPPER TROUGH EJECTING NEWD FROM THE ROCKIES INTO
KS/NE. A COLD FRONT WILL ALSO APPROACH THE AREA WHICH SHOULD
PROVIDE AN ENHANCED FOCUS FOR TSTM DEVELOPMENT. SEVERE WEATHER
WILL CONTINUE TO BE POSSIBLE SUNDAY AND INTO MONDAY INCLUDING A
THREAT FOR ISOLATED TORNADOES. ABUNDANT DEEP LAYER MOISTURE AND
THE CONTINUED HIGH RAIN CHANCES POINT TO LOCALLY HEAVY RAINFALL
BEING POSSIBLE. RAINFALL AMOUNTS THROUGH 12Z MONDAY MORNING COULD
EASILY BE BETWEEN 2 AND 4 INCHES WITH THE HIGHEST AMOUNTS MOST
LIKELY ACROSS THE NW HALF OF THE AREA.
THE FRONT WILL BECOME STATIONARY JUST SOUTH OF THE CWA EARLY NEXT
WEEK. A SERIES OF SHORTWAVE TROUGHS ALOFT INTERACTING WITH THE
FRONT AND THE DEVELOPMENT OF A SFC LOW OVER S TX WILL KEEP RAIN
CHANCES IN THE FORECAST THROUGH THE REMAINDER OF THE EXTENDED TIME
FRAME. /09/
AVIATION...
EXPECT SCT SHOWERS AND TSTMS TO CONTINUE ACROSS DEEP E TX...NW
LA...AND S AR THROUGH SUNRISE OF THIS FRIDAY MORNING. THE RAINS
SHOULD WEAKEN AND END BEFORE LUNCHTIME LATE THIS FRIDAY MORNING.
IN THE MEANTIME...SOME SCT MVFR CEILINGS POSSIBLE DURING THIS
FRIDAY MORNING NEAR AND AFTER SUNRISE. VFR CONDITIONS TO THEN
DOMINATE DURING THIS FRIDAY AFTERNOON AND EVENING. BY SATURDAY
MORNING NEAR SUNRISE...MORE SCT TSTMS REMAIN POSSIBLE WITH MVFR
CEILINGS AS WELL. /VIII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 71 85 70 82 / 30 30 30 60
MLU 69 86 69 85 / 10 30 20 30
DEQ 69 81 68 78 / 50 40 60 70
TXK 69 83 68 80 / 40 40 50 70
ELD 70 84 69 83 / 30 30 30 50
TYR 69 83 71 81 / 40 40 40 70
GGG 71 84 71 82 / 30 30 40 60
LFK 72 85 72 84 / 30 30 20 50
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1106 AM CDT FRI MAY 8 2015
.DISCUSSION...
SCATTERED CONVECTION CONTINUES TO LINGER ACROSS PARTS OF THE
REGION THIS MORNING...AND THIS WILL LIKELY BE THE WAY OF IT FOR
THE REMAINDER OF THE DAY. DAYTIME HEATING IS EXPECTED TO CONTRIBUTE
TO REDEVELOPMENT THIS AFTERNOON. THE NORTHWESTERN HALF OF OUR
REGION IS UNDER A SLIGHT RISK FOR SEVERE THUNDERSTORMS...AND THE
PRIMARY THREATS WITH ANY STORMS WILL BE DAMAGING WINDS AND HEAVY
RAINFALL. THE FLOODING THREAT WILL BE FAR MORE ENHANCED OVER THE
AREAS THAT RECEIVED HEAVY RAINFALL OVERNIGHT AND THIS MORNING. FOR
THE UPDATE...HAVE MADE SOME MINOR ADJUSTMENTS TO POPS/WX/QPF...BUT
OTHERWISE...THE FCST IS IN GOOD SHAPE. /12/
&&
.PREV DISCUSSION... /ISSUED 830 AM CDT FRI MAY 8 2015/
DISCUSSION...
WHAT IS LEFT OF THE OVERNIGHT MCS CONTINUES TO MOVE EASTWARD JUST
NORTH OF I-20 IN EXTREME EAST TEXAS AND NORTHERN LOUISIANA WITH
SCATTERED CONVECTION REDEVELOPING FARTHER NORTHWEST. TWO CELLS OF
PRIMARY CONCERN. THE FIRST IS WHAT USED TO BE THE SWRN END OF THE
MCS...WHICH IS JUST EAST OF MINDEN LA AS OF 13Z.
THE SECOND STORM IS MOVING INTO CADDO PARISH AND OUT OF E TX.
EXTREMELY HEAVY RAINFALL OCCURRED EARLIER OVER HARRISON COUNTY. 6
INCHES OF RAIN WAS MEASURED NORTH OF HALLSVILLE AND CONSIDERABLE
FLASH FLOODING WAS ALSO REPORTED. THIS CELL IS DISSIPATING AS IT
MOVES INTO AIR THAT HAS BEEN SOMEWHAT STABILIZED BY COOL OUTFLOW
FROM THE OLD MCS TO THE EAST.
HAVE UPDATED POP/QPF/WX GRIDS THROUGH 18Z. /09/
PREV DISCUSSION... /ISSUED 445 AM CDT FRI MAY 8 2015/
.CORRECTED TO INCLUDE AVIATION DISCUSSION...
DISCUSSION...
MCS CONTINUES TO MARCH EASTWARD BUT IS ALSO GRADUALLY WEAKENING.
LATEST HRRR HAS HANDLED THE CONVECTION QUITE WELL TONIGHT WITH THE
EXCEPTION OF BEING TOO SLOW. RADAR TRENDS ALSO PROMOTE HIGHER
CONFIDENCE IN THE HRRR IN REGARDS TO THE CONVECTION MOVING ACROSS
THE REMAINDER OF OUR NRN LA PARISHES/SRN AR COUNTIES NORTH OF
I-20 WHICH SHOULD OCCUR AROUND 12-14Z BASED ON CURRENT SPEEDS.
HAVE ONCE INCLUDED PRE-FIRST PERIOD WORDING TO HANDLE POPS PRIOR
TO 12Z THIS MORNING. WILL LIKELY SEND A ZFP UPDATE AFTER THAT TIME
TO CLEAN UP THE TEXT.
WITH THE MCS EXPECTED TO EXIT THE AREA EARLY IN THE
MORNING...LOCATIONS AFFECTED BY THE RAIN THIS MORNING SHOULD HAVE
PLENTY OF TIME TO RECOVER. RESIDUAL OUTFLOW BOUNDARIES COMBINED
WITH SEA BREEZE ACTIVITY SHOULD ONCE AGAIN LEAD TO ISOLATED TO
WIDELY SCATTERED CONVECTION BY EARLY AFTERNOON. YET ANOTHER MCS IS
EXPECTED TO DEVELOP UPSTREAM ACROSS SRN OK SOUTHWARD INTO TX. THE
NAM HAS CONSISTENTLY BEEN TOO FAST OVER THE LAST SEVERAL DAYS WITH
MOVING CONVECTION INTO THE ARKLATEX. HOWEVER...OTHER MODELS ALSO
INDICATE SHWRS/TSTMS MOVING INTO AREAS NW OF A TYLER TO PRESCOTT
LINE PRIOR TO 09/06Z SO HAVE INCLUDED LIKELY POPS BEGINNING THIS
EVENING. A SEVERE WEATHER THREAT IS IN PLAY MAINLY IN THE FORM OF
DAMAGING WINDS.
SATURDAY`S FORECAST IS PRETTY MUCH A REPEAT OF TODAY. ONE ROUND OF
CONVECTION SHOULD END DURING THE MORNING FOLLOWED BY ANOTHER
STRONG TO SEVERE CONVECTIVE COMPLEX DURING THE LATE AFTERNOON AND
INTO THE OVERNIGHT HRS. POPS WILL CONTINUE TO INCREASE GOING INTO
SUNDAY AND MONDAY AS LARGE SCALE ASCENT SPREADS OVER THE AREA IN
RESPONSE TO AN UPPER TROUGH EJECTING NEWD FROM THE ROCKIES INTO
KS/NE. A COLD FRONT WILL ALSO APPROACH THE AREA WHICH SHOULD
PROVIDE AN ENHANCED FOCUS FOR TSTM DEVELOPMENT. SEVERE WEATHER
WILL CONTINUE TO BE POSSIBLE SUNDAY AND INTO MONDAY INCLUDING A
THREAT FOR ISOLATED TORNADOES. ABUNDANT DEEP LAYER MOISTURE AND
THE CONTINUED HIGH RAIN CHANCES POINT TO LOCALLY HEAVY RAINFALL
BEING POSSIBLE. RAINFALL AMOUNTS THROUGH 12Z MONDAY MORNING COULD
EASILY BE BETWEEN 2 AND 4 INCHES WITH THE HIGHEST AMOUNTS MOST
LIKELY ACROSS THE NW HALF OF THE AREA.
THE FRONT WILL BECOME STATIONARY JUST SOUTH OF THE CWA EARLY NEXT
WEEK. A SERIES OF SHORTWAVE TROUGHS ALOFT INTERACTING WITH THE
FRONT AND THE DEVELOPMENT OF A SFC LOW OVER S TX WILL KEEP RAIN
CHANCES IN THE FORECAST THROUGH THE REMAINDER OF THE EXTENDED TIME
FRAME. /09/
AVIATION...
EXPECT SCT SHOWERS AND TSTMS TO CONTINUE ACROSS DEEP E TX...NW
LA...AND S AR THROUGH SUNRISE OF THIS FRIDAY MORNING. THE RAINS
SHOULD WEAKEN AND END BEFORE LUNCHTIME LATE THIS FRIDAY MORNING.
IN THE MEANTIME...SOME SCT MVFR CEILINGS POSSIBLE DURING THIS
FRIDAY MORNING NEAR AND AFTER SUNRISE. VFR CONDITIONS TO THEN
DOMINATE DURING THIS FRIDAY AFTERNOON AND EVENING. BY SATURDAY
MORNING NEAR SUNRISE...MORE SCT TSTMS REMAIN POSSIBLE WITH MVFR
CEILINGS AS WELL. /VIII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 85 71 85 70 / 30 30 30 30
MLU 87 69 86 69 / 50 10 30 20
DEQ 83 69 81 68 / 50 50 40 60
TXK 84 69 83 68 / 50 40 40 50
ELD 85 70 84 69 / 50 30 30 30
TYR 85 69 83 71 / 30 40 40 40
GGG 85 71 84 71 / 30 30 30 40
LFK 87 72 85 72 / 30 30 30 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
12
AREA FORECAST DISCUSSION...UPDATED
NWS SHREVEPORT LA
830 AM CDT FRI MAY 8 2015
.DISCUSSION...
WHAT IS LEFT OF THE OVERNIGHT MCS CONTINUES TO MOVE EASTWARD JUST
NORTH OF I-20 IN EXTREME EAST TEXAS AND NORTHERN LOUISIANA WITH
SCATTERED CONVECTION REDEVELOPING FARTHER NORTHWEST. TWO CELLS OF
PRIMARY CONCERN. THE FIRST IS WHAT USED TO BE THE SWRN END OF THE
MCS...WHICH IS JUST EAST OF MINDEN LA AS OF 13Z.
THE SECOND STORM IS MOVING INTO CADDO PARISH AND OUT OF E TX.
EXTREMELY HEAVY RAINFALL OCCURRED EARLIER OVER HARRISON COUNTY. 6
INCHES OF RAIN WAS MEASURED NORTH OF HALLSVILLE AND CONSIDERABLE
FLASH FLOODING WAS ALSO REPORTED. THIS CELL IS DISSIPATING AS IT
MOVES INTO AIR THAT HAS BEEN SOMEWHAT STABILIZED BY COOL OUTFLOW
FROM THE OLD MCS TO THE EAST.
HAVE UPDATED POP/QPF/WX GRIDS THROUGH 18Z. /09/
&&
.PREV DISCUSSION... /ISSUED 445 AM CDT FRI MAY 8 2015/
..CORRECTED TO INCLUDE AVIATION DISCUSSION...
DISCUSSION...
MCS CONTINUES TO MARCH EASTWARD BUT IS ALSO GRADUALLY WEAKENING.
LATEST HRRR HAS HANDLED THE CONVECTION QUITE WELL TONIGHT WITH THE
EXCEPTION OF BEING TOO SLOW. RADAR TRENDS ALSO PROMOTE HIGHER
CONFIDENCE IN THE HRRR IN REGARDS TO THE CONVECTION MOVING ACROSS
THE REMAINDER OF OUR NRN LA PARISHES/SRN AR COUNTIES NORTH OF
I-20 WHICH SHOULD OCCUR AROUND 12-14Z BASED ON CURRENT SPEEDS.
HAVE ONCE INCLUDED PRE-FIRST PERIOD WORDING TO HANDLE POPS PRIOR
TO 12Z THIS MORNING. WILL LIKELY SEND A ZFP UPDATE AFTER THAT TIME
TO CLEAN UP THE TEXT.
WITH THE MCS EXPECTED TO EXIT THE AREA EARLY IN THE
MORNING...LOCATIONS AFFECTED BY THE RAIN THIS MORNING SHOULD HAVE
PLENTY OF TIME TO RECOVER. RESIDUAL OUTFLOW BOUNDARIES COMBINED
WITH SEA BREEZE ACTIVITY SHOULD ONCE AGAIN LEAD TO ISOLATED TO
WIDELY SCATTERED CONVECTION BY EARLY AFTERNOON. YET ANOTHER MCS IS
EXPECTED TO DEVELOP UPSTREAM ACROSS SRN OK SOUTHWARD INTO TX. THE
NAM HAS CONSISTENTLY BEEN TOO FAST OVER THE LAST SEVERAL DAYS WITH
MOVING CONVECTION INTO THE ARKLATEX. HOWEVER...OTHER MODELS ALSO
INDICATE SHWRS/TSTMS MOVING INTO AREAS NW OF A TYLER TO PRESCOTT
LINE PRIOR TO 09/06Z SO HAVE INCLUDED LIKELY POPS BEGINNING THIS
EVENING. A SEVERE WEATHER THREAT IS IN PLAY MAINLY IN THE FORM OF
DAMAGING WINDS.
SATURDAY`S FORECAST IS PRETTY MUCH A REPEAT OF TODAY. ONE ROUND OF
CONVECTION SHOULD END DURING THE MORNING FOLLOWED BY ANOTHER
STRONG TO SEVERE CONVECTIVE COMPLEX DURING THE LATE AFTERNOON AND
INTO THE OVERNIGHT HRS. POPS WILL CONTINUE TO INCREASE GOING INTO
SUNDAY AND MONDAY AS LARGE SCALE ASCENT SPREADS OVER THE AREA IN
RESPONSE TO AN UPPER TROUGH EJECTING NEWD FROM THE ROCKIES INTO
KS/NE. A COLD FRONT WILL ALSO APPROACH THE AREA WHICH SHOULD
PROVIDE AN ENHANCED FOCUS FOR TSTM DEVELOPMENT. SEVERE WEATHER
WILL CONTINUE TO BE POSSIBLE SUNDAY AND INTO MONDAY INCLUDING A
THREAT FOR ISOLATED TORNADOES. ABUNDANT DEEP LAYER MOISTURE AND
THE CONTINUED HIGH RAIN CHANCES POINT TO LOCALLY HEAVY RAINFALL
BEING POSSIBLE. RAINFALL AMOUNTS THROUGH 12Z MONDAY MORNING COULD
EASILY BE BETWEEN 2 AND 4 INCHES WITH THE HIGHEST AMOUNTS MOST
LIKELY ACROSS THE NW HALF OF THE AREA.
THE FRONT WILL BECOME STATIONARY JUST SOUTH OF THE CWA EARLY NEXT
WEEK. A SERIES OF SHORTWAVE TROUGHS ALOFT INTERACTING WITH THE
FRONT AND THE DEVELOPMENT OF A SFC LOW OVER S TX WILL KEEP RAIN
CHANCES IN THE FORECAST THROUGH THE REMAINDER OF THE EXTENDED TIME
FRAME. /09/
AVIATION...
EXPECT SCT SHOWERS AND TSTMS TO CONTINUE ACROSS DEEP E TX...NW
LA...AND S AR THROUGH SUNRISE OF THIS FRIDAY MORNING. THE RAINS
SHOULD WEAKEN AND END BEFORE LUNCHTIME LATE THIS FRIDAY MORNING.
IN THE MEANTIME...SOME SCT MVFR CEILINGS POSSIBLE DURING THIS
FRIDAY MORNING NEAR AND AFTER SUNRISE. VFR CONDITIONS TO THEN
DOMINATE DURING THIS FRIDAY AFTERNOON AND EVENING. BY SATURDAY
MORNING NEAR SUNRISE...MORE SCT TSTMS REMAIN POSSIBLE WITH MVFR
CEILINGS AS WELL. /VIII/.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 85 71 85 70 / 50 30 30 30
MLU 87 69 86 69 / 50 10 30 20
DEQ 83 69 81 68 / 50 50 40 60
TXK 84 69 83 68 / 50 40 40 50
ELD 85 70 84 69 / 30 30 30 30
TYR 85 69 83 71 / 30 40 40 40
GGG 85 71 84 71 / 40 30 30 40
LFK 87 72 85 72 / 30 30 30 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
445 AM CDT FRI MAY 8 2015
.DISCUSSION...
MCS CONTINUES TO MARCH EASTWARD BUT IS ALSO GRADUALLY WEAKENING.
LATEST HRRR HAS HANDLED THE CONVECTION QUITE WELL TONIGHT WITH THE
EXCEPTION OF BEING TOO SLOW. RADAR TRENDS ALSO PROMOTE HIGHER
CONFIDENCE IN THE HRRR IN REGARDS TO THE CONVECTION MOVING ACROSS
THE REMAINDER OF OUR NRN LA PARISHES/SRN AR COUNTIES NORTH OF
I-20 WHICH SHOULD OCCUR AROUND 12-14Z BASED ON CURRENT SPEEDS.
HAVE ONCE INCLUDED PRE-FIRST PERIOD WORDING TO HANDLE POPS PRIOR
TO 12Z THIS MORNING. WILL LIKELY SEND A ZFP UPDATE AFTER THAT TIME
TO CLEAN UP THE TEXT.
WITH THE MCS EXPECTED TO EXIT THE AREA EARLY IN THE
MORNING...LOCATIONS AFFECTED BY THE RAIN THIS MORNING SHOULD HAVE
PLENTY OF TIME TO RECOVER. RESIDUAL OUTFLOW BOUNDARIES COMBINED
WITH SEA BREEZE ACTIVITY SHOULD ONCE AGAIN LEAD TO ISOLATED TO
WIDELY SCATTERED CONVECTION BY EARLY AFTERNOON. YET ANOTHER MCS IS
EXPECTED TO DEVELOP UPSTREAM ACROSS SRN OK SOUTHWARD INTO TX. THE
NAM HAS CONSISTENTLY BEEN TOO FAST OVER THE LAST SEVERAL DAYS WITH
MOVING CONVECTION INTO THE ARKLATEX. HOWEVER...OTHER MODELS ALSO
INDICATE SHWRS/TSTMS MOVING INTO AREAS NW OF A TYLER TO PRESCOTT
LINE PRIOR TO 09/06Z SO HAVE INCLUDED LIKELY POPS BEGINNING THIS
EVENING. A SEVERE WEATHER THREAT IS IN PLAY MAINLY IN THE FORM OF
DAMAGING WINDS.
SATURDAY`S FORECAST IS PRETTY MUCH A REPEAT OF TODAY. ONE ROUND OF
CONVECTION SHOULD END DURING THE MORNING FOLLOWED BY ANOTHER
STRONG TO SEVERE CONVECTIVE COMPLEX DURING THE LATE AFTERNOON AND
INTO THE OVERNIGHT HRS. POPS WILL CONTINUE TO INCREASE GOING INTO
SUNDAY AND MONDAY AS LARGE SCALE ASCENT SPREADS OVER THE AREA IN
RESPONSE TO AN UPPER TROUGH EJECTING NEWD FROM THE ROCKIES INTO
KS/NE. A COLD FRONT WILL ALSO APPROACH THE AREA WHICH SHOULD
PROVIDE AN ENHANCED FOCUS FOR TSTM DEVELOPMENT. SEVERE WEATHER
WILL CONTINUE TO BE POSSIBLE SUNDAY AND INTO MONDAY INCLUDING A
THREAT FOR ISOLATED TORNADOES. ABUNDANT DEEP LAYER MOISTURE AND
THE CONTINUED HIGH RAIN CHANCES POINT TO LOCALLY HEAVY RAINFALL
BEING POSSIBLE. RAINFALL AMOUNTS THROUGH 12Z MONDAY MORNING COULD
EASILY BE BETWEEN 2 AND 4 INCHES WITH THE HIGHEST AMOUNTS MOST
LIKELY ACROSS THE NW HALF OF THE AREA.
THE FRONT WILL BECOME STATIONARY JUST SOUTH OF THE CWA EARLY NEXT
WEEK. A SERIES OF SHORTWAVE TROUGHS ALOFT INTERACTING WITH THE
FRONT AND THE DEVELOPMENT OF A SFC LOW OVER S TX WILL KEEP RAIN
CHANCES IN THE FORECAST THROUGH THE REMAINDER OF THE EXTENDED TIME
FRAME. /09/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 85 71 85 70 / 40 30 30 30
MLU 87 69 86 69 / 50 10 30 20
DEQ 83 69 81 68 / 30 50 40 60
TXK 84 69 83 68 / 30 40 40 50
ELD 85 70 84 69 / 40 30 30 30
TYR 85 69 83 71 / 30 40 40 40
GGG 85 71 84 71 / 30 30 30 40
LFK 87 72 85 72 / 30 30 30 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS KCAR
ISSUED BY NATIONAL WEATHER SERVICE GRAY ME
912 AM EDT FRI MAY 8 2015
.SYNOPSIS...
A COLD FRONT WILL STALL SOUTHWEST OF THE REGION TODAY WHILE AN
UPPER LEVEL DISTURBANCE FROM QUEBEC SLIDES SOUTHEAST ACROSS
NORTHEAST PORTIONS OF THE REGION. THIS FRONT WILL SLOWLY MOVE
BACK NORTHEAST ACROSS THE REGION TONIGHT AND SATURDAY. A SLOW
MOVING COLD FRONT FROM QUEBEC WILL THEN CROSS THE REGION LATE
SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
---910AM UPDATE---
RADAR INDICATING SHOWERS CONTINUING OVER EXTREME NORTHERN PORTIONS
OF THE CWA THIS MORNING. HAVE RECEIVED SOME REPORTS OF GRAUPEL
WHICH IS NOT OVERLY SURPRISING WHEN CONSIDERING HOW LOW THE
FREEZING LEVEL AND WBZ HEIGHTS ARE. NOT REALLY MAKING MUCH IN THE
WAY OF CHANGES THIS MORNING. HAVE TWEAKED A FEW ELEMENTS FOR
CURRENT TRENDS.
600 AM UPDATE: BASED ON LATEST FCST HRLY HRRR SIM RADAR AND CAN-AM
RADAR IMAGERY...WE TM SHIFTED THE ARRIVAL OF SHWRS ACROSS THE N BACK
BY 2 HRS. THIS RESULTED IN A SLIGHT REDUCTION IN QPF IN THE 06-12Z
TM PD THIS MORN. SHWRS SHOULD STILL EXIT/DISSIPATE ACROSS NE PTNS
OF THE REGION ARND MIDDAY. OTHERWISE...MINOR ADJUSTMENTS WERE MADE
TO FCST HRLY TEMPS BASED ON 5-6 AM OBSVD TEMPS.
ORGNL DISC: A WEAK S/WV MOVG SE FROM NRN QB OVR NE PTNS OF THE FA
THIS MORN WILL LIKELY RESULT IN SHWRS OVR THIS PTN OF THE FA...BUT
WITH VERY DRY SUB CLD AIR...WE ARE NOT SURE HOW MUCH RN WILL REACH
THE SFC...SO WE LOWERED FCST QPF BULLSEYES FOR BOTH THE 06-12Z AND
12-18Z TM FRAMES BY SEVERAL HUNDREDTHS OF AN INCH. ANY SHWR
ACTIVITY SHOULD THEN MOVE SE OUT OF THE FA BY ERLY AFTN AS THE
S/WV MOVES SE INTO SRN NB. HI TEMPS WILL BE MUCH COOLER THAN YSTDY
AFTN ACROSS THE REGION...BUT WILL NEED TO BE MONITORED...SPCLY IF
WE GET MORE SUNSHINE THEN CURRENTLY ANTICIPATED SINCE THE AIR MASS
BEHIND THE BACK DOOR COLD FRONT IS UNUSUALLY DRY...LIKELY A RESULT
OF THE ORIGIN BEING OVR LAND AREAS OF FAR NRN QB AND LABRADOR...
MEANING THAT TEMPS COULD RESPOND QUICKLY AND RISE ABV OUR CURRENT
HI TEMPS FCST FOR OUR REGION.
TONIGHT SHOULD BE RNFL FREE...BEGINNING MCLR TO PTLY CLDY...BUT
WITH RETURN SRLY FLOW INCREASING ABV THE BL LATE TNGT...OCEAN ST
SHOULD ADVECT NWRD OVR LAND BY DAYBREAK SUN...AFFECTING DOWNEAST
AREAS FIRST. OVRNGT LOWS WILL BE RELATIVELY MILD FOR THIS TM OF
SEASON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A WARM FRONT WILL SLOWLY WORK ITS WAY THROUGH THE AREA SATURDAY
MORNING UNDER A GROWING UPPER RIDGE. THE DAY STARTS WITH A STEEP
FRONTAL INVERSION AND WIDESPREAD LOW CLOUDS. THE INVERSION WILL
SLOWLY ERODE OVER THE COURSE OF THE DAY FOR THE NORTHWEST PORTION
OF THE FORECAST AREA AND ALLOW HIGHS IN THE UPPER 60S WITH MUCH
HIGHER HUMIDITY. THE ARRIVAL OF THE WARMER AND MORE HUMID AIR IS
SLOWER THAN HAD BEEN PREVIOUSLY EXPECTED. THE DOWN EAST REGION
WILL MAINTAIN THE INVERSION ALL DAY AND HIGHS WILL ONLY REACH THE
UPPER 40S TO LOWER 50S WITH AN ONSHORE FLOW. WHILE THE UPPER RIDGE
SHOULD HOLD ON INTO SUNDAY...A WEAK COLD FRONTAL BOUNDARY WILL BE
TO THE NORTHWEST OF THE STATE IN QUEBEC BY LATER SATURDAY. THIS
BOUNDARY WILL BE THE DIVIDING LINE BETWEEN A LARGE CANADIAN HIGH
AND WARM/MOIST AIR MASS TO THE SOUTH. UNFORTUNATELY...THE FRONT
WILL BE OVER THE FORECAST AREA FROM SATURDAY NIGHT INTO SUNDAY
NIGHT. FOR SATURDAY NIGHT...THE HUMID AIR MASS WILL FINALLY BE IN
PLACE AND LOWS WILL ONLY DROP TO THE LOWER 50S EXCEPT ALONG COAST
WHERE MID 40S ARE ANTICIPATED. FOG AND DRIZZLE WILL DEVELOP ALONG
THE COAST AND SPREAD NORTH LATER SATURDAY NIGHT. FOR THE CROWN OF
MAINE...THE FRONTAL BOUNDARY WILL EASE INTO THE AREA AND THERE ARE
CONTINUED SIGNS OF ELEVATED INSTABILITY AS THE THERMAL RIDGE
BUILDS ALOFT. HAVE ADDED ISOLATED THUNDERSTORMS TO SATURDAY
NIGHT`S FORECAST.
FOR SUNDAY...THE COLD FRONT WILL SLOWLY SAG SOUTHWARD DURING THE
DAY. THIS MEANS MOSTLY CLOUDY SKIES WITH SHOWERS. HAVE NOT ADDED
MENTION OF ANY THUNDERSTORMS YET AS IT REMAINS UNCLEAR HOW MUCH
INSTABILITY WILL OCCUR AND WHERE. GUIDANCE CONTINUES PROVIDE A
VARIETY OF SOLUTIONS REGARDING THE SPEED OF THE FRONT AND ANY AXIS
OF INSTABILITY. IT IS CLEAR THAT IT WILL BE THE MOST HUMID DAY OF
THE SEASON FOR BANGOR AND DOWN EAST WITH DEW POINTS APPROACHING
60F. THIS WILL BE ACCOMPANIED BY HIGHS IN THE MID TO UPPER 70S.
WITH GREATER CLOUD COVER IN NORTHERN AROOSTOOK...HIGHS WILL BE IN
THE MID TO UPPER 60S. THE COAST WILL ALSO BE COOLER...BUT WINDS
WILL BE LESS ONSHORE AND TEMPERATURES WILL REACH INTO THE 60S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ON SUNDAY NIGHT...THE FRONT WILL STALL JUST SOUTH OF THE FORECAST
AREA AND RETURN AS A WARM FRONT LATER MONDAY. IN THE
MEANTIME...HIGH PRESSURE BUILDS NORTH AND PROVIDES A DECENT SHOT
AT A DRY MONDAY FOR THE NORTHERN HALF OF THE FORECAST AREA. A
BROAD AREA OF LOW PRESSURE WILL THEN MOVE EASTWARD ALONG THE WARM
FRONTAL BOUNDARY MONDAY NIGHT INTO TUESDAY. PRECIPITATION IS
EXPECTED TO BE MORE STRATIFORM AND HAVE SPECIFIED RAIN RATHER THAN
SHOWERS FOR MOST AREAS UNTIL TUESDAY NIGHT. THE UPPER TROUGH
CROSSES WEDNESDAY AND PRODUCES ANOTHER DAY OF SHOWERS. DRIER
CONDITIONS AND HIGH PRESSURE WILL FINALLY RETURN WEDNESDAY NIGHT
THROUGH FRIDAY.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION
TODAY INTO THIS EVENING...WITH LOWER VFR CLGS WITH LGT SHWRS
POSSIBLE OVR NRN TAF SITES THIS MORN. LOWER OCEAN ST MOVG
INLAND COULD RESULT IN MVFR CLGS OVR DOWNEAST SITES LATE TNGT.
SHORT TERM: MVFR TO IFR CIGS ARE FORECAST SATURDAY MORNING. CIGS
WILL PROBABLY STAY MVFR ALL DAY FOR MOST SITES AND COULD BE IFR
ALL DAY ALONG THE COASTAL SITES SUCH AS BHB. FOG AND LOW CLOUDS
WILL CAUSE IFR CONDITIONS FOR SATURDAY NIGHT INTO SUNDAY MORNING
AT ALL TERMINALS. THUNDERSTORMS ARE POSSIBLE SATURDAY NIGHT NORTH
OF HUL.
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS ACROSS ALL THE WATERS OVERNIGHT. A SMALL CRAFT ADVISORY IS
IN EFFECT FRIDAY FOR THE SOUTHWEST COASTAL WATERS...WITH
CONDITIONS EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS
ACROSS THE REST OF THE WATERS.
SHORT TERM: WINDS AND SEAS BELOW SCA THROUGH THE PERIOD. FOG WILL
BE AN ISSUE STARTING SATURDAY AND CONTINUING INTO MONDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ051.
&&
$$
POHL
AREA FORECAST DISCUSSION
NWS CARIBOU ME
610 AM EDT FRI MAY 8 2015
.SYNOPSIS...
A COLD FRONT WILL STALL SOUTHWEST OF THE REGION TODAY WHILE AN
UPPER LEVEL DISTURBANCE FROM QUEBEC SLIDES SOUTHEAST ACROSS
NORTHEAST PORTIONS OF THE REGION. THIS FRONT WILL SLOWLY MOVE
BACK NORTHEAST ACROSS THE REGION TONIGHT AND SATURDAY. A SLOW
MOVING COLD FRONT FROM QUEBEC WILL THEN CROSS THE REGION LATE
SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
600 AM UPDATE: BASED ON LATEST FCST HRLY HRRR SIM RADAR AND CAN-AM
RADAR IMAGERY...WE TM SHIFTED THE ARRIVAL OF SHWRS ACROSS THE N BACK
BY 2 HRS. THIS RESULTED IN A SLIGHT REDUCTION IN QPF IN THE 06-12Z
TM PD THIS MORN. SHWRS SHOULD STILL EXIT/DISSIPATE ACROSS NE PTNS
OF THE REGION ARND MIDDAY. OTHERWISE...MINOR ADJUSTMENTS WERE MADE
TO FCST HRLY TEMPS BASED ON 5-6 AM OBSVD TEMPS.
ORGNL DISC: A WEAK S/WV MOVG SE FROM NRN QB OVR NE PTNS OF THE FA
THIS MORN WILL LIKELY RESULT IN SHWRS OVR THIS PTN OF THE FA...BUT
WITH VERY DRY SUB CLD AIR...WE ARE NOT SURE HOW MUCH RN WILL REACH
THE SFC...SO WE LOWERED FCST QPF BULLSEYES FOR BOTH THE 06-12Z AND
12-18Z TM FRAMES BY SEVERAL HUNDREDTHS OF AN INCH. ANY SHWR
ACTIVITY SHOULD THEN MOVE SE OUT OF THE FA BY ERLY AFTN AS THE
S/WV MOVES SE INTO SRN NB. HI TEMPS WILL BE MUCH COOLER THAN YSTDY
AFTN ACROSS THE REGION...BUT WILL NEED TO BE MONITORED...SPCLY IF
WE GET MORE SUNSHINE THEN CURRENTLY ANTICIPATED SINCE THE AIR MASS
BEHIND THE BACK DOOR COLD FRONT IS UNUSUALLY DRY...LIKELY A RESULT
OF THE ORIGIN BEING OVR LAND AREAS OF FAR NRN QB AND LABRADOR...
MEANING THAT TEMPS COULD RESPOND QUICKLY AND RISE ABV OUR CURRENT
HI TEMPS FCST FOR OUR REGION.
TONIGHT SHOULD BE RNFL FREE...BEGINNING MCLR TO PTLY CLDY...BUT
WITH RETURN SRLY FLOW INCREASING ABV THE BL LATE TNGT...OCEAN ST
SHOULD ADVECT NWRD OVR LAND BY DAYBREAK SUN...AFFECTING DOWNEAST
AREAS FIRST. OVRNGT LOWS WILL BE RELATIVELY MILD FOR THIS TM OF
SEASON.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
A WARM FRONT WILL SLOWLY WORK ITS WAY THROUGH THE AREA SATURDAY
MORNING UNDER A GROWING UPPER RIDGE. THE DAY STARTS WITH A STEEP
FRONTAL INVERSION AND WIDESPREAD LOW CLOUDS. THE INVERSION WILL
SLOWLY ERODE OVER THE COURSE OF THE DAY FOR THE NORTHWEST PORTION
OF THE FORECAST AREA AND ALLOW HIGHS IN THE UPPER 60S WITH MUCH
HIGHER HUMIDITY. THE ARRIVAL OF THE WARMER AND MORE HUMID AIR IS
SLOWER THAN HAD BEEN PREVIOUSLY EXPECTED. THE DOWN EAST REGION
WILL MAINTAIN THE INVERSION ALL DAY AND HIGHS WILL ONLY REACH THE
UPPER 40S TO LOWER 50S WITH AN ONSHORE FLOW. WHILE THE UPPER RIDGE
SHOULD HOLD ON INTO SUNDAY...A WEAK COLD FRONTAL BOUNDARY WILL BE
TO THE NORTHWEST OF THE STATE IN QUEBEC BY LATER SATURDAY. THIS
BOUNDARY WILL BE THE DIVIDING LINE BETWEEN A LARGE CANADIAN HIGH
AND WARM/MOIST AIR MASS TO THE SOUTH. UNFORTUNATELY...THE FRONT
WILL BE OVER THE FORECAST AREA FROM SATURDAY NIGHT INTO SUNDAY
NIGHT. FOR SATURDAY NIGHT...THE HUMID AIR MASS WILL FINALLY BE IN
PLACE AND LOWS WILL ONLY DROP TO THE LOWER 50S EXCEPT ALONG COAST
WHERE MID 40S ARE ANTICIPATED. FOG AND DRIZZLE WILL DEVELOP ALONG
THE COAST AND SPREAD NORTH LATER SATURDAY NIGHT. FOR THE CROWN OF
MAINE...THE FRONTAL BOUNDARY WILL EASE INTO THE AREA AND THERE ARE
CONTINUED SIGNS OF ELEVATED INSTABILITY AS THE THERMAL RIDGE
BUILDS ALOFT. HAVE ADDED ISOLATED THUNDERSTORMS TO SATURDAY
NIGHT`S FORECAST.
FOR SUNDAY...THE COLD FRONT WILL SLOWLY SAG SOUTHWARD DURING THE
DAY. THIS MEANS MOSTLY CLOUDY SKIES WITH SHOWERS. HAVE NOT ADDED
MENTION OF ANY THUNDERSTORMS YET AS IT REMAINS UNCLEAR HOW MUCH
INSTABILITY WILL OCCUR AND WHERE. GUIDANCE CONTINUES PROVIDE A
VARIETY OF SOLUTIONS REGARDING THE SPEED OF THE FRONT AND ANY AXIS
OF INSTABILITY. IT IS CLEAR THAT IT WILL BE THE MOST HUMID DAY OF
THE SEASON FOR BANGOR AND DOWN EAST WITH DEW POINTS APPROACHING
60F. THIS WILL BE ACCOMPANIED BY HIGHS IN THE MID TO UPPER 70S.
WITH GREATER CLOUD COVER IN NORTHERN AROOSTOOK...HIGHS WILL BE IN
THE MID TO UPPER 60S. THE COAST WILL ALSO BE COOLER...BUT WINDS
WILL BE LESS ONSHORE AND TEMPERATURES WILL REACH INTO THE 60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ON SUNDAY NIGHT...THE FRONT WILL STALL JUST SOUTH OF THE FORECAST
AREA AND RETURN AS A WARM FRONT LATER MONDAY. IN THE
MEANTIME...HIGH PRESSURE BUILDS NORTH AND PROVIDES A DECENT SHOT
AT A DRY MONDAY FOR THE NORTHERN HALF OF THE FORECAST AREA. A
BROAD AREA OF LOW PRESSURE WILL THEN MOVE EASTWARD ALONG THE WARM
FRONTAL BOUNDARY MONDAY NIGHT INTO TUESDAY. PRECIPITATION IS
EXPECTED TO BE MORE STRATIFORM AND HAVE SPECIFIED RAIN RATHER THAN
SHOWERS FOR MOST AREAS UNTIL TUESDAY NIGHT. THE UPPER TROUGH
CROSSES WEDNESDAY AND PRODUCES ANOTHER DAY OF SHOWERS. DRIER
CONDITIONS AND HIGH PRESSURE WILL FINALLY RETURN WEDNESDAY NIGHT
THROUGH FRIDAY.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION
TODAY INTO THIS EVENING...WITH LOWER VFR CLGS WITH LGT SHWRS
POSSIBLE OVR NRN TAF SITES THIS MORN. LOWER OCEAN ST MOVG
INLAND COULD RESULT IN MVFR CLGS OVR DOWNEAST SITES LATE TNGT.
SHORT TERM: MVFR TO IFR CIGS ARE FORECAST SATURDAY MORNING. CIGS
WILL PROBABLY STAY MVFR ALL DAY FOR MOST SITES AND COULD BE IFR
ALL DAY ALONG THE COASTAL SITES SUCH AS BHB. FOG AND LOW CLOUDS
WILL CAUSE IFR CONDITIONS FOR SATURDAY NIGHT INTO SUNDAY MORNING
AT ALL TERMINALS. THUNDERSTORMS ARE POSSIBLE SATURDAY NIGHT NORTH
OF HUL.
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS ACROSS ALL THE WATERS OVERNIGHT. A SMALL CRAFT ADVISORY IS
IN EFFECT FRIDAY FOR THE SOUTHWEST COASTAL WATERS...WITH
CONDITIONS EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS
ACROSS THE REST OF THE WATERS.
SHORT TERM: WINDS AND SEAS BELOW SCA THROUGH THE PERIOD. FOG WILL
BE AN ISSUE STARTING SATURDAY AND CONTINUING INTO MONDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ051.
&&
$$
NEAR TERM...VJN
SHORT TERM...MCW
LONG TERM...MCW
AVIATION...VJN/MCW
MARINE...VJN/MCW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
215 PM EDT FRI MAY 8 2015
.SYNOPSIS...
SUBTROPICAL STORM ANA MEANDERS OFF THE SOUTHEAST COAST THROUGH
THE WEEKEND...BEFORE WEAKENING AND MOVING ONSHORE LATE SUNDAY
INTO SUNDAY NIGHT. MEANWHILE...HIGH PRESSURE REMAINS OVER THE
LOCAL AREA THROUGH THE WEEKEND. THE REMNANT LOW OF ANA WILL LIFT
ALONG THE MID ATLANTIC COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...FOG HAS DISSIPATED ACROSS THE VIRGINIA EASTERN SHORE AND
MOST OF THE MARYLAND LOWER EASTERN SHORE AS OF 1000 AM. FOGGY
CONDITIONS LINGER ACROSS THE MARYLAND BEACHES FROM ASSATEAGUE TO
OCEAN CITY AND SHOULD IMPROVE WITHIN THE NEXT HOUR. A SPECIAL
WEATHER STATEMENT HAS BEEN ISSUED.
PREVIOUS DISCUSSION...UPPER/SFC HIGH PRESSURE PREVAILS OVER THE
LOCAL THIS MORNING AS SUBTROPICAL STORM ANA REMAINS NEARLY
STATIONARY ROUGHLY 150 MILES OFF THE GA/SC COAST. FLOW REMAINS
WEAK UNDER THE INFLUENCE OF THE MID-UPPER LEVEL RIDGE...WHICH HAS
ALLOWED DENSE FOG TO PERSIST OVER THE VA/MD ERN SHORE. LATEST
11-3.9U SATELLITE TRENDS INDICATE THAT THE DENSE FOG IS STRUGGLING
TO PUSH WWD OVER THE BAY AND INTO THE ERN VA PENINSULAS THANKS TO
DRIER AIR...BUT HAS SPREAD/DEVELOPED OVER THE LOWER CHESAPEAKE BAY
AND SOUTHSIDE HAMPTON ROAD. THE TRENDS ARE CONTRADICTORY TO HI-RES
GUIDANCE...WHICH CONTINUES TO INDICATE FOG WILL ADVECT AS FAR AS
CNTRL VA. WILL CONTINUE WITH DENSE FOG ADVISORY OVER THE ERN SHORE
THRU 8AM...AND INCLUDE AREAS OF FOG ACROSS SOUTHEAST VA. AN SPS
HAS ALSO BEEN ISSUED. FOG DISSIPATES/LIFTS BY MID MORNING.
VORT LOBE VISIBLE ON WATER VAPOR CURRENTLY LIFTING ACROSS ERN NC
EARLY THIS MORNING...WITH LIGHT RAIN SPREADING AS FAR NORTH AS THE
PAMLICO SOUND. LATEST RAP GUIDANCE LIFTS THE VORT MAX OVER THE SE
COUNTIES AROUND DAYBREAK...ALONG WITH DEEPER MOISTURE (PWATS ~1.3
INCHES). HOWEVER...WATER VAPOR IMAGERY ALSO DEPICTS ANTICYCLONIC
FLOW OVER THE LOCAL AREA. RESULTANT SUBSIDENCE WILL LIKELY PREVENT
MUCH MORE THAN A SPRINKLE OR LIGHT SHOWER THIS MORNING ACROSS THE
SE. WILL MAINTAIN LOW-END CHANCE POPS THIS MORNING...BUT RAINFALL
AMOUNTS WILL GENERALLY BE ONLY A FEW HUNDREDTHS OF AN INCH. BAND
DISSIPATES AS IT ENCOUNTERS DRIER/MORE STABLE AIR OVER CNTRL VA.
ADDITIONAL BANDS OF ENERGY AND MOISTURE PROGGED TO ROUND THE NRN
PERIPHERY OF ANA THIS AFTERNOON. LOW LEVEL MOISTURE AND THETA-E
ADVECTION IN TANDEM WITH TEMPS IN THE MID-UPPER 70S WILL PROVIDE FOR
MLCAPE VALUES AOB 500 J/KG ACROSS THE SE COUNTIES.
HOWEVER...LIMITATIONS OF ONSHORE FLOW...WEAK WIND FIELDS...MEAGER
LIFT AND WARM TEMPS ALOFT WILL RESULT IN LITTLE MORE THAN ISOLATED
TO WIDELY SCATTERED SHOWERS AND MAYBE A RUMBLE OF THUNDER. DRY
CONDITIONS EXPECTED ELSEWHERE. SIMILAR THICKNESSES TO 24 HRS AGO AND
H85 TEMPS +1 STD DEV WILL RESULT IN ANOTHER WARM DAY. HIGHS INLAND
GENERALLY IN THE LOW 80S. COOLER IN THE SE DUE TO THICKER CLOUD
COVER AND ONSHORE FLOW...WITH HIGHS IN THE MID-UPPER 70S. EVEN
COOLER ALONG THE IMMEDIATE COAST WITH HIGHS IN THE UPPER 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
LOCAL AREA REMAINS UNDER THE INFLUENCE OF THE UPPER LEVEL RIDGE THRU
THE SHORT TERM. A POTENT SHORTWAVE OVER THE INTERMOUNTAIN WEST WILL
LIFT INTO THE CNTRL PLAINS SAT AS THE RIDGE AXIS PUSHES OFF THE ERN
SEABOARD. WHILE FLOW ALOFT REMAINS WEAK...MODELS PROG THE MEANDERING
ANA TO BEGIN LIFTING SLOWLY WNW SAT AND FINALLY ONSHORE OVER SC SUN.
FOR THE WAKEFIELD AREA...MAIN SENSIBLE WEATHER IMPACTS FROM ANA
CONTINUE TO BE ISOLATED TO SCATTERED DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS...HIGH SEAS AND RIP CURRENTS. OTHERWISE...WARM
TEMPS AND OVERNIGHT PATCHY FOG PERSISTS.
HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE SRN COUNTIES TONIGHT
AS PIECES OF ENERGY AND MOISTURE LIFT OVER THE REGION.
HOWEVER...WITH LIMITED LOW LEVEL FORCING EXPECT MOST LOCALES TO
REMAIN DRY. INCREASING MOISTURE SAT AND SUN ALONG WITH MEAGER
AFTERNOON INSTABILITY WILL RESULT IN BETTER CHANCES FOR SHOWERS AND
POSSIBLY A THUNDERSTORM ACROSS THE AREA. THE BEST CHANCES WILL BE
INLAND WHERE CHANCE POPS HAVE BEEN MAINTAINED. BETTER COVERAGE
EXPECTED SUN AFTERNOON AS BETTER UPPER LEVEL SUPPORT ARRIVES ONSHORE
IN TANDEM WITH DEEPER MOISTURE. MAIN LIMITATION CONTINUES TO BE
LARGE SCALE SUBSIDENCE DUE TO THE UPPER LEVEL RIDGE AND WARM TEMPS
ALOFT. PWATS GENERALLY AOB 1.5 INCHES...WHICH COMBINED WITH ONLY
MODEST DYNAMICS WILL LIMIT TOTAL QPF AMOUNTS.
HIGHS SAT AND SUN REMAIN SLIGHTLY ABOVE NORMAL...GENERALLY IN THE
LOW 80S INLAND AND THE MID-UPPER 70S ALONG THE COAST. IMMEDIATE
COAST MAY ONLY WARM INTO THE MID-UPPER 60S DUE TO PERSISTENT ONSHORE
FLOW. LOWS GENERALLY IN THE LOW TO MID 60S THRU THE SHORT TERM.
SKIES AVG PARTLY CLOUDY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WK/REMNANT SFC LO PRES FCST TO TRACK NE INVOF NC/VA/MD CST SUN
NGT/MON...THEN AWAY FM THE RGN THEREAFTER. OTRW...HI PRES RMNS
ANCHORED OFF THE SE CONUS CST. A CDFNT CROSSES THE RGN TUE
NGT..THEN OFFSHORE WED. WILL CONT ISOLD/SCT POPS...ESP DAYTIME
HRS MON AND TUE...THEN TREND POPS DOWN W-E WED-THU POST CDFNT.
WARMER THAN NORMAL WX XPCD TO CONT SUN NGT THROUGH TUE...THEN BACK
CLOSER TO NORMAL WED/THU. HI TEMPS THROUGH TUE IN THE 80S...EXCEPT
COOLER 70S IMMEDIATE COAST. LOWS IN THE 60S. HI TEMPS WED/THU
RANGING THROUGH THE 70S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AN OUTER BAND AROUND SUBTROPICAL STORM ANA IS MOVING THROUGH ERN
NC AND THE VA TIDEWATER THIS AFTERNOON AND IS PRODUCING MVFR LEVEL
CLOUDS BETWEEN 1K - 2K FT. THE MODELS FORECAST THAT THIS BAND WILL
CONTINUE TO LIFT NW THIS AFTERNOON AND EVENING BEFORE BEGINNING TO
WEAKEN AS IT MOVES AWAY FROM THE WATER SOURCE.
THE NEXT QUESTION IS FOG AND LOW CLOUDS TONIGHT. THE SFC HIGH TO
THE NORTH IS SLIDING FURTHER OFF THE COAST THE FLOW IS EXPECT TO
BECOME MORE E - SE OVERNIGHT. THE NE FLOW LAST NIGHT PRODUCED
SIGNIFICANT FOG FOR THE DELMARVA AND THE NAM IN PARTICULAR IS
SHOWING LIFR CONDITIONS FOR ALL TAF SITES TONIGHT. CAN SEE
CONDITIONS BEING FAVORABLE TO FOG AT SBY TONIGHT...BUT FURTHER
SOUTH...CONFIDENCE IS LOW AS THE AIRMASS SHOULD BECOME MORE
TROPICAL WITH DEWPOINTS RISING INTO THE MID 60S TOWARD SUNRISE. SO
FOR NOW HAVE SHOWN SOME MVFR FOG FOR RIC/PHF AND VFR CONDITIONS AT
ORF/ECG. WILL HAVE TO CONTINUE TO MONITOR CONDITIONS OVER THE NEXT
12 HRS TO SEE IF CONDITIONS TO BECOME FAVORABLE FOR FOG
DEVELOPMENT 6Z - 13Z.
WITH MOISTURE THINNING SAT MORNING AFTER 12Z...SHOULD SEE VFR
CONDITIONS AREA WIDE AS SUB TS ANA CONTINUES TO SPIN OFF THE SC
COAST.
NEXT CHANCE FOR WIDESPREAD MVFR TO IFR CONDITIONS COMES ON MONDAY
AS THE MOISTURE ASSOCIATED WITH ANA MOVES NORTHWARD INTO THE AREA.
&&
.MARINE...
WITH 1 PM UPDATE...HAVE DROPPED DENSE FOG ADVISORY AS
VISIBILITIES...BASED ON SATELLITE IMAGERY APPEAR TO BE IMPROVING.
ALSO THE WINDS HAVE NOT BEEN AS STRONG AS MODELS INDICATED FOR
SOUTHERN WATERS AND SEAS ARE STILL BELOW 4 NORTH OF THE VA/NC
BORDER. MODELS ARE SHOWING THE WINDS REMAINING 10 TO 15 KT SO HAVE
DROPPED SCA NORTH OF VA/NC BORDER.
PVS DSCN:
DESPITE SUB TRPCL STORM ANA OFF THE SC COAST...MARINE CONDITIONS
ACROSS AKQ WATERS RTHR TRANQUIL ATTM AND WILL LIKELY STAY THAT WAY
AS THE SYSTM IS EXPECTED TO HAVE LITTLE MOVEMENT NORTH OVER THE
NEXT FEW DAYS. EXCEPTION BEING SEAS WHERE THEY HAVE INCREASED TO
NEAR 5 FEET ACROSS NRN OUTER BANKS AND DATA SUGGESTS THAT SOME 5
FOOTERS MAKE IT AS FAR NORTH AS OFF THE VA BCH COAST LATER TODAY
AND TONIGHT SO WILL CARRY SCA HEADLINES FOR SEAS MAINLY SOUTH OF
CAPE CHARLES LGHT THRU TONIGHT AND INTO SAT ACROSS NC CSTL WTRS.
SEAS PROGGED TO SUBSIDE A BIT AS THE CENTER OF ANA MOVES ONSHORE
THIS WEEKEND DESPITE THE PERSISTENT ONSHORE FLOW. HAVE DROPPED
SEAS TO JUST BLO SCA LVLS FOR NOW WITH THE EXPECTATION THAT SEAS
MIGHT INCREASE ERLY NEXT WEEK AS THE REMNANT CIRCULATION GETS
DRAWN N-NE AHEAD OF APPRCHG TROF. WINDS EXPECTED TO REMAIN AOB 15
KTS THRU SUN.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR ANZ658.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...BMD/SAM
SHORT TERM...SAM
LONG TERM...ALB
AVIATION...ESS
MARINE...ESS/MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1019 AM EDT FRI MAY 8 2015
.SYNOPSIS...
SUBTROPICAL STORM ANA MEANDERS OFF THE SOUTHEAST COAST THROUGH
THE WEEKEND...BEFORE WEAKENING AND MOVING ONSHORE LATE SUNDAY
INTO SUNDAY NIGHT. MEANWHILE...HIGH PRESSURE REMAINS OVER THE
LOCAL AREA THROUGH THE WEEKEND. THE REMNANT LOW OF ANA WILL LIFT
ALONG THE MID ATLANTIC COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...FOG HAS DISSIPATED ACROSS THE VIRGINIA EASTERN SHORE AND
MOST OF THE MARYLAND LOWER EASTERN SHORE AS OF 1000 AM. FOGGY
CONDITIONS LINGER ACROSS THE MARYLAND BEACHES FROM ASSATEAGUE TO
OCEAN CITY AND SHOULD IMPROVE WITHIN THE NEXT HOUR. A SPECIAL
WEATHER STATEMENT HAS BEEN ISSUED.
PREVIOUS DISCUSSION...UPPER/SFC HIGH PRESSURE PREVAILS OVER THE
LOCAL THIS MORNING AS SUBTROPICAL STORM ANA REMAINS NEARLY
STATIONARY ROUGHLY 150 MILES OFF THE GA/SC COAST. FLOW REMAINS
WEAK UNDER THE INFLUENCE OF THE MID-UPPER LEVEL RIDGE...WHICH HAS
ALLOWED DENSE FOG TO PERSIST OVER THE VA/MD ERN SHORE. LATEST
11-3.9U SATELLITE TRENDS INDICATE THAT THE DENSE FOG IS STRUGGLING
TO PUSH WWD OVER THE BAY AND INTO THE ERN VA PENINSULAS THANKS TO
DRIER AIR...BUT HAS SPREAD/DEVELOPED OVER THE LOWER CHESAPEAKE BAY
AND SOUTHSIDE HAMPTON ROAD. THE TRENDS ARE CONTRADICTORY TO HI-RES
GUIDANCE...WHICH CONTINUES TO INDICATE FOG WILL ADVECT AS FAR AS
CNTRL VA. WILL CONTINUE WITH DENSE FOG ADVISORY OVER THE ERN SHORE
THRU 8AM...AND INCLUDE AREAS OF FOG ACROSS SOUTHEAST VA. AN SPS
HAS ALSO BEEN ISSUED. FOG DISSIPATES/LIFTS BY MID MORNING.
VORT LOBE VISIBLE ON WATER VAPOR CURRENTLY LIFTING ACROSS ERN NC
EARLY THIS MORNING...WITH LIGHT RAIN SPREADING AS FAR NORTH AS THE
PAMLICO SOUND. LATEST RAP GUIDANCE LIFTS THE VORT MAX OVER THE SE
COUNTIES AROUND DAYBREAK...ALONG WITH DEEPER MOISTURE (PWATS ~1.3
INCHES). HOWEVER...WATER VAPOR IMAGERY ALSO DEPICTS ANTICYCLONIC
FLOW OVER THE LOCAL AREA. RESULTANT SUBSIDENCE WILL LIKELY PREVENT
MUCH MORE THAN A SPRINKLE OR LIGHT SHOWER THIS MORNING ACROSS THE
SE. WILL MAINTAIN LOW-END CHANCE POPS THIS MORNING...BUT RAINFALL
AMOUNTS WILL GENERALLY BE ONLY A FEW HUNDREDTHS OF AN INCH. BAND
DISSIPATES AS IT ENCOUNTERS DRIER/MORE STABLE AIR OVER CNTRL VA.
ADDITIONAL BANDS OF ENERGY AND MOISTURE PROGGED TO ROUND THE NRN
PERIPHERY OF ANA THIS AFTERNOON. LOW LEVEL MOISTURE AND THETA-E
ADVECTION IN TANDEM WITH TEMPS IN THE MID-UPPER 70S WILL PROVIDE FOR
MLCAPE VALUES AOB 500 J/KG ACROSS THE SE COUNTIES.
HOWEVER...LIMITATIONS OF ONSHORE FLOW...WEAK WIND FIELDS...MEAGER
LIFT AND WARM TEMPS ALOFT WILL RESULT IN LITTLE MORE THAN ISOLATED
TO WIDELY SCATTERED SHOWERS AND MAYBE A RUMBLE OF THUNDER. DRY
CONDITIONS EXPECTED ELSEWHERE. SIMILAR THICKNESSES TO 24 HRS AGO AND
H85 TEMPS +1 STD DEV WILL RESULT IN ANOTHER WARM DAY. HIGHS INLAND
GENERALLY IN THE LOW 80S. COOLER IN THE SE DUE TO THICKER CLOUD
COVER AND ONSHORE FLOW...WITH HIGHS IN THE MID-UPPER 70S. EVEN
COOLER ALONG THE IMMEDIATE COAST WITH HIGHS IN THE UPPER 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
LOCAL AREA REMAINS UNDER THE INFLUENCE OF THE UPPER LEVEL RIDGE THRU
THE SHORT TERM. A POTENT SHORTWAVE OVER THE INTERMOUNTAIN WEST WILL
LIFT INTO THE CNTRL PLAINS SAT AS THE RIDGE AXIS PUSHES OFF THE ERN
SEABOARD. WHILE FLOW ALOFT REMAINS WEAK...MODELS PROG THE MEANDERING
ANA TO BEGIN LIFTING SLOWLY WNW SAT AND FINALLY ONSHORE OVER SC SUN.
FOR THE WAKEFIELD AREA...MAIN SENSIBLE WEATHER IMPACTS FROM ANA
CONTINUE TO BE ISOLATED TO SCATTERED DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS...HIGH SEAS AND RIP CURRENTS. OTHERWISE...WARM
TEMPS AND OVERNIGHT PATCHY FOG PERSISTS.
HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE SRN COUNTIES TONIGHT
AS PIECES OF ENERGY AND MOISTURE LIFT OVER THE REGION.
HOWEVER...WITH LIMITED LOW LEVEL FORCING EXPECT MOST LOCALES TO
REMAIN DRY. INCREASING MOISTURE SAT AND SUN ALONG WITH MEAGER
AFTERNOON INSTABILITY WILL RESULT IN BETTER CHANCES FOR SHOWERS AND
POSSIBLY A THUNDERSTORM ACROSS THE AREA. THE BEST CHANCES WILL BE
INLAND WHERE CHANCE POPS HAVE BEEN MAINTAINED. BETTER COVERAGE
EXPECTED SUN AFTERNOON AS BETTER UPPER LEVEL SUPPORT ARRIVES ONSHORE
IN TANDEM WITH DEEPER MOISTURE. MAIN LIMITATION CONTINUES TO BE
LARGE SCALE SUBSIDENCE DUE TO THE UPPER LEVEL RIDGE AND WARM TEMPS
ALOFT. PWATS GENERALLY AOB 1.5 INCHES...WHICH COMBINED WITH ONLY
MODEST DYNAMICS WILL LIMIT TOTAL QPF AMOUNTS.
HIGHS SAT AND SUN REMAIN SLIGHTLY ABOVE NORMAL...GENERALLY IN THE
LOW 80S INLAND AND THE MID-UPPER 70S ALONG THE COAST. IMMEDIATE
COAST MAY ONLY WARM INTO THE MID-UPPER 60S DUE TO PERSISTENT ONSHORE
FLOW. LOWS GENERALLY IN THE LOW TO MID 60S THRU THE SHORT TERM.
SKIES AVG PARTLY CLOUDY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WK/REMNANT SFC LO PRES FCST TO TRACK NE INVOF NC/VA/MD CST SUN
NGT/MON...THEN AWAY FM THE RGN THEREAFTER. OTRW...HI PRES RMNS
ANCHORED OFF THE SE CONUS CST. A CDFNT CROSSES THE RGN TUE
NGT..THEN OFFSHORE WED. WILL CONT ISOLD/SCT POPS...ESP DAYTIME
HRS MON AND TUE...THEN TREND POPS DOWN W-E WED-THU POST CDFNT.
WARMER THAN NORMAL WX XPCD TO CONT SUN NGT THROUGH TUE...THEN BACK
CLOSER TO NORMAL WED/THU. HI TEMPS THROUGH TUE IN THE 80S...EXCEPT
COOLER 70S IMMEDIATE COAST. LOWS IN THE 60S. HI TEMPS WED/THU
RANGING THROUGH THE 70S.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
CSTL VSBYS QUICKLY IMPROVING EXCEPT AT SBY WHERE DATA SUGGESTS IT
MAY HANG ARND A FEW MORE HRS. OTW...CONDITIONS IMPROVE TO MVFR
THEN VFR DUE TO SCT-BKN SC CIGS. LOW CONFIDENCE ABOUT WHETHER ANY
BANDS OF SHWRS FROM ANA CAN MAKE IT NORTH OF THE VA BRDER SO KEPT
THE TAFS DRY WITH THE 12Z ISSUANCE. ECG MAY SEE SCT SHWRS AFTR 16Z
BUT TIMING ANY SHWR IS PROBLEMATIC ATTM.
GIVEN LITTLE CHANGE/MOVEMENT IN SYNOPTIC FEATURES...COULD VERY
WELL SEE A REPEAT OF LOW CLOUDS AND PTCHY FOG AGAIN TONIGHT.
&&
.MARINE...
DENSE FOG WITH VISIBILITIES OF ONE MILE OR LESS CONTINUES FROM
FENWICK ISLAND TO PARRAMORE ISLAND THROUGH 100 PM. CONDITIONS
FINALLY IMPROVE THEREAFTER WITH FOG LIFTING AND DISSIPATING WITH
AFTERNOON MIXING.
PVS DSCN:
DESPITE SUB TRPCL STORM ANA OFF THE SC COAST...MARINE CONDITIONS
ACROSS AKQ WATERS RTHR TRANQUIL ATTM AND WILL LIKELY STAY THAT WAY
AS THE SYSTM IS EXPECTED TO HAVE LITTLE MOVEMENT NORTH OVER THE
NEXT FEW DAYS. EXCEPTION BEING SEAS WHERE THEY HAVE INCREASED TO
NEAR 5 FEET ACROSS NRN OUTER BANKS AND DATA SUGGESTS THAT SOME 5
FOOTERS MAKE IT AS FAR NORTH AS OFF THE VA BCH COAST LATER TODAY
AND TONIGHT SO WILL CARRY SCA HEADLINES FOR SEAS MAINLY SOUTH OF
CAPE CHARLES LGHT THRU TONIGHT AND INTO SAT ACROSS NC CSTL WTRS.
SEAS PROGGED TO SUBSIDE A BIT AS THE CENTER OF ANA MOVES ONSHORE
THIS WEEKEND DESPITE THE PERSISTENT ONSHORE FLOW. HAVE DROPPED
SEAS TO JUST BLO SCA LVLS FOR NOW WITH THE EXPECTATION THAT SEAS
MIGHT INCREASE ERLY NEXT WEEK AS THE REMNANT CIRCULATION GETS
DRAWN N-NE AHEAD OF APPRCHG TROF. WINDS EXPECTED TO REMAIN AOB 15
KTS THRU SUN.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ650-
652-654.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR ANZ658.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR ANZ656.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...BMD/SAM
SHORT TERM...SAM
LONG TERM...ALB
AVIATION...MPR
MARINE...MPR/ESS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
642 AM EDT FRI MAY 8 2015
.SYNOPSIS...
SUBTROPICAL STORM ANA MEANDERS OFF THE SOUTHEAST COAST THROUGH
THE WEEKEND...BEFORE WEAKENING AND MOVING ONSHORE LATE SUNDAY
INTO SUNDAY NIGHT. MEANWHILE...HIGH PRESSURE REMAINS OVER THE
LOCAL AREA THROUGH THE WEEKEND. THE REMNANT LOW OF ANA WILL LIFT
ALONG THE MID-ATLANTIC COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER/SFC HIGH PRESSURE PREVAILS OVER THE LOCAL THIS MORNING AS
SUBTROPICAL STORM ANA REMAINS NEARLY STATIONARY ROUGHLY 150 MILES
OFF THE GA/SC COAST. FLOW REMAINS WEAK UNDER THE INFLUENCE OF THE
MID-UPPER LEVEL RIDGE...WHICH HAS ALLOWED DENSE FOG TO PERSIST OVER
THE VA/MD ERN SHORE. LATEST 11-3.9U SATELLITE TRENDS INDICATE THAT
THE DENSE FOG IS STRUGGLING TO PUSH WWD OVER THE BAY AND INTO THE
ERN VA PENINSULAS THANKS TO DRIER AIR...BUT HAS SPREAD/DEVELOPED
OVER THE LOWER CHESAPEAKE BAY AND SOUTHSIDE HAMPTON ROAD. THE TRENDS
ARE CONTRADICTORY TO HI-RES GUIDANCE...WHICH CONTINUES TO INDICATE
FOG WILL ADVECT AS FAR AS CNTRL VA. WILL CONTINUE WITH DENSE FOG
ADVISORY OVER THE ERN SHORE THRU 8AM...AND INCLUDE AREAS OF FOG
ACROSS SOUTHEAST VA. AN SPS HAS ALSO BEEN ISSUED. FOG
DISSIPATES/LIFTS BY MID MORNING.
VORT LOBE VISIBLE ON WATER VAPOR CURRENTLY LIFTING ACROSS ERN NC
EARLY THIS MORNING...WITH LIGHT RAIN SPREADING AS FAR NORTH AS THE
PAMLICO SOUND. LATEST RAP GUIDANCE LIFTS THE VORT MAX OVER THE SE
COUNTIES AROUND DAYBREAK...ALONG WITH DEEPER MOISTURE (PWATS ~1.3
INCHES). HOWEVER...WATER VAPOR IMAGERY ALSO DEPICTS ANTICYCLONIC
FLOW OVER THE LOCAL AREA. RESULTANT SUBSIDENCE WILL LIKELY PREVENT
MUCH MORE THAN A SPRINKLE OR LIGHT SHOWER THIS MORNING ACROSS THE
SE. WILL MAINTAIN LOW-END CHANCE POPS THIS MORNING...BUT RAINFALL
AMOUNTS WILL GENERALLY BE ONLY A FEW HUNDREDTHS OF AN INCH. BAND
DISSIPATES AS IT ENCOUNTERS DRIER/MORE STABLE AIR OVER CNTRL VA.
ADDITIONAL BANDS OF ENERGY AND MOISTURE PROGGED TO ROUND THE NRN
PERIPHERY OF ANA THIS AFTERNOON. LOW LEVEL MOISTURE AND THETA-E
ADVECTION IN TANDEM WITH TEMPS IN THE MID-UPPER 70S WILL PROVIDE FOR
MLCAPE VALUES AOB 500 J/KG ACROSS THE SE COUNTIES.
HOWEVER...LIMITATIONS OF ONSHORE FLOW...WEAK WIND FIELDS...MEAGER
LIFT AND WARM TEMPS ALOFT WILL RESULT IN LITTLE MORE THAN ISOLATED
TO WIDELY SCATTERED SHOWERS AND MAYBE A RUMBLE OF THUNDER. DRY
CONDITIONS EXPECTED ELSEWHERE. SIMILAR THICKNESSES TO 24 HRS AGO AND
H85 TEMPS +1 STD DEV WILL RESULT IN ANOTHER WARM DAY. HIGHS INLAND
GENERALLY IN THE LOW 80S. COOLER IN THE SE DUE TO THICKER CLOUD
COVER AND ONSHORE FLOW...WITH HIGHS IN THE MID-UPPER 70S. EVEN
COOLER ALONG THE IMMEDIATE COAST WITH HIGHS IN THE UPPER 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
LOCAL AREA REMAINS UNDER THE INFLUENCE OF THE UPPER LEVEL RIDGE THRU
THE SHORT TERM. A POTENT SHORTWAVE OVER THE INTERMOUNTAIN WEST WILL
LIFT INTO THE CNTRL PLAINS SAT AS THE RIDGE AXIS PUSHES OFF THE ERN
SEABOARD. WHILE FLOW ALOFT REMAINS WEAK...MODELS PROG THE MEANDERING
ANA TO BEGIN LIFTING SLOWLY WNW SAT AND FINALLY ONSHORE OVER SC SUN.
FOR THE WAKEFIELD AREA...MAIN SENSIBLE WEATHER IMPACTS FROM ANA
CONTINUE TO BE ISOLATED TO SCATTERED DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS...HIGH SEAS AND RIP CURRENTS. OTHERWISE...WARM
TEMPS AND OVERNIGHT PATCHY FOG PERSISTS.
HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE SRN COUNTIES TONIGHT
AS PIECES OF ENERGY AND MOISTURE LIFT OVER THE REGION.
HOWEVER...WITH LIMITED LOW LEVEL FORCING EXPECT MOST LOCALES TO
REMAIN DRY. INCREASING MOISTURE SAT AND SUN ALONG WITH MEAGER
AFTERNOON INSTABILITY WILL RESULT IN BETTER CHANCES FOR SHOWERS AND
POSSIBLY A THUNDERSTORM ACROSS THE AREA. THE BEST CHANCES WILL BE
INLAND WHERE CHANCE POPS HAVE BEEN MAINTAINED. BETTER COVERAGE
EXPECTED SUN AFTERNOON AS BETTER UPPER LEVEL SUPPORT ARRIVES ONSHORE
IN TANDEM WITH DEEPER MOISTURE. MAIN LIMITATION CONTINUES TO BE
LARGE SCALE SUBSIDENCE DUE TO THE UPPER LEVEL RIDGE AND WARM TEMPS
ALOFT. PWATS GENERALLY AOB 1.5 INCHES...WHICH COMBINED WITH ONLY
MODEST DYNAMICS WILL LIMIT TOTAL QPF AMOUNTS.
HIGHS SAT AND SUN REMAIN SLIGHTLY ABOVE NORMAL...GENERALLY IN THE
LOW 80S INLAND AND THE MID-UPPER 70S ALONG THE COAST. IMMEDIATE
COAST MAY ONLY WARM INTO THE MID-UPPER 60S DUE TO PERSISTENT ONSHORE
FLOW. LOWS GENERALLY IN THE LOW TO MID 60S THRU THE SHORT TERM.
SKIES AVG PARTLY CLOUDY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WK/REMNANT SFC LO PRES FCST TO TRACK NE INVOF NC/VA/MD CST SUN
NGT/MON...THEN AWAY FM THE RGN THEREAFTER. OTRW...HI PRES RMNS
ANCHORED OFF THE SE CONUS CST. A CDFNT CROSSES THE RGN TUE
NGT..THEN OFFSHORE WED. WILL CONT ISOLD/SCT POPS...ESP DAYTIME
HRS MON AND TUE...THEN TREND POPS DOWN W-E WED-THU POST CDFNT.
WARMER THAN NORMAL WX XPCD TO CONT SUN NGT THROUGH TUE...THEN BACK
CLOSER TO NORMAL WED/THU. HI TEMPS THROUGH TUE IN THE 80S...EXCEPT
COOLER 70S IMMEDIATE COAST. LOWS IN THE 60S. HI TEMPS WED/THU
RANGING THROUGH THE 70S.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
CSTL VSBYS QUICKLY IMPROVING EXCEPT AT SBY WHERE DATA SUGGESTS IT
MAY HANG ARND A FEW MORE HRS. OTW...CONDITIONS IMPROVE TO MVFR
THEN VFR DUE TO SCT-BKN SC CIGS. LOW CONFIDENCE ABOUT WHETHER ANY
BANDS OF SHWRS FROM ANA CAN MAKE IT NORTH OF THE VA BRDER SO KEPT
THE TAFS DRY WITH THE 12Z ISSUANCE. ECG MAY SEE SCT SHWRS AFTR 16Z
BUT TIMING ANY SHWR IS PROBLEMATIC ATTM.
GIVEN LITTLE CHANGE/MOVMNT IN SYNOPTIC FEATURES...COULD VERY WELL
SEE A REPEAT OF LOW CLOUDS AND PTCHY FOG AGAIN TONIGHT.
&&
.MARINE...
THE PTCHY DENSE FOG HAS DSPTD ACROSS THE BAY THUS HAVE DROPPED THE
DENSE FOG ADVSRY THERE. DENSE FOG CONTINUES ALONG THE CSTL WATERS
ALONG THE EN SHORE AND DATA SUGGESTS IT LINGERS A FEW MORE HRS SO
EXTENDED THE ADVSRY THERE TRU 10 AM.
PVS DSCN:
DESPITE SUB TRPLCL STORM ANA OFF THE SC COAST...MARINE CONDITIONS
ACROSS AKQ WATERS RTHR TRANQUIL ATTM AND WILL LIKELY STAY THAT WAY
AS THE SYSTM IS EXPECTED TO HAVE LITTLE MOVMNT NORTH OVER THE NEXT
FEW DAYS. EXCEPTION BEING SEAS WHERE THEY HAVE INCREASED TO NEAR 5
FEET ACROSS NRN OUTER BANKS AND DATA SUGGESTS THAT SOME 5 FOOTERS
MAKE IT AS FAR NORTH AS OFF THE VA BCH COAST LATER TODAY AND TONIGHT
SO WILL CARRY SCA HEADLINES FOR SEAS MAINLY SOUTH OF CAPE CHARLES
LGHT THRU TONIGHT AND INTO SAT ACROSS NC CSTL WTRS.
SEAS PROGGED TO SUBSIDE A BIT AS THE CENTER OF ANA MOVES ONSHORE
THIS WEEKEND DESPITE THE PERSISTANT ONSHORE FLOW. HAVE DROPPED SEAS
TO JUST BLO SCA LVLS FOR NOW WITH THE EXPECTATION THAT SEAS MIGHT
INCREASE ERLY NEXT WEEK AS THE REMNANT CIRCULATION GETS DRAWN N-NE
AHEAD OF APPRCHG TROF. WINDS EXPECTED TO REMAIN AOB 15 KTS THRU SUN.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MDZ024-025.
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ021>023.
NC...NONE.
VA...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR VAZ099-100.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ650-652-
654.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR ANZ656.
SMALL CRAFT ADVISORY UNTIL 1 PM EDT SATURDAY FOR ANZ658.
&&
$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...ALB
AVIATION...MPR
MARINE...MPR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
612 AM EDT FRI MAY 8 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND WITH
SCATTERED SHOWERS AND STORMS POSSIBLE EACH AFTERNOON...MAINLY OVER
THE HIGHER TERRAIN.
&&
.NEAR TERM /THROUGH SATURDAY/...
CURRENT IR SATELLITE IMAGERY SHOWING A THIN VEIL OF HIGH CIRRUS
MOVING OVER THE EASTERN 1/3 OF THE FORECAST AREA. THESE CLOUDS
HELPED TO KEEP TEMPERATURES SLIGHTLY WARMER OVERNIGHT...AND KEPT
FOG FROM DEVELOPING.
EXPECTING THE HIGH CLOUDS TO EVACUATE BY MID-MORNING...LEADING TO
ANOTHER MORNING OF ABUNDANT SUNSHINE AND A QUICK WARM-UP. ALL
SIGNS POINT TO AN EVEN WARMER DAY THAN THURSDAY...AS LOW TO MID-
LEVEL TEMPERATURES PUSH EVEN HIGHER WITH THE LOW-LEVEL FLOW
VEERING TO SOUTHERLY. LATEST RAP IS CONSIDERABLY WARMER THAN THE
REST OF THE GUIDANCE WITH 850MB TEMPS NEARING 20C. THIS COMBINED
WITH SUNSHINE WOULD MEAN TEMPERATURES REACHING INTO THE 90S. AT
THIS POINT...FEEL THESE MID-LEVEL TEMPS ARE UNATTAINABLE IN THE
ABSENCE OF A STRONG WARM AIR ADVECTION SIGNAL. WILL KEEP HIGH
TEMPERATURES CLOSER TO THE WARM MET NUMBERS.
THE WARM SUMMER-LIKE AIR MASS SHOULD ONCE AGAIN GENERATE ISOLATED
OR SCATTERED SHOWERS/THUNDERSTORMS OVER THE ELEVATED HEAT SOURCE
OF THE HIGH TERRAIN. OTHERWISE...NOT CARRYING RAIN CHANCES THROUGH
TONIGHT. YET ANOTHER MILD NIGHT TONIGHT WITH TEMPERATURES EXPECTED
TO BE 10-15 DEGREES ABOVE NORMAL.
TAX
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
THE STATUS QUO IS BASICALLY MAINTAINED INTO THE SHORT TERM PERIOD
AS UPPER RIDGING REMAINS IN CONTROL OF THE AREA INTO THE EARLY
PART OF NEXT WEEK. GUIDANCE HAS LARGELY SLOWED THE APPROACH OF THE
UPPER LOW THAT HAS BEEN SITTING OVER THE INTERMOUNTAIN WEST ALL
WEEK AS IT EJECTS TOWARD THE GREAT LAKES. THIS RESULTS IN WARM
CONDITIONS PERSISTING RIGHT INTO MONDAY.
RELATIVELY CONTINUOUS SOUTHWESTERLY FLOW SHOULD KEEP HUMID
CONDITIONS IN PLACE. POOR MODEL-TO-MODEL AND RUN-TO-RUN
CONSISTENCY EXISTS WITH A WEAK SHORT WAVE TROUGH EMBEDDED IN THE
SOUTHWESTERLY FLOW ON SUNDAY. YET AGAIN WITH THE 00Z CYCLE
TONIGHT...SOME MODELS FAVOR IT...OTHERS DO NOT. BECAUSE OF THE
WARM/HUMID AIR MASS IN PLACE...INSTABILITY WILL LIKELY CONTINUE TO
BE HIGH...AND GIVEN THAT A LIFTING MECHANISM WILL BE REQUIRED TO
GENERATE MUCH IN THE WAY OF CONVECTION...CHANCE POPS FOR
SHOWERS/STORMS WERE MAINTAINED GIVEN THE POSSIBILITY OF THE WAVE
PASSAGE ON SUNDAY. OTHERWISE...A SLOWER TRANSITION EASTWARD OF
LARGE SCALE RIDGING MEANS LARGELY DRY CONDITIONS INTO EARLY NEXT
WEEK.
AS 850 MB TEMPERATURES LINGER IN THE MID TEENS...HIGHS WILL
CONTINUE TO REMAIN IN THE MID AND UPPER 80S. OVERNIGHT LOWS ALSO
LOOK TO REMAIN LARGELY IN THE 60S...THOUGH WITH EACH PASSING
NIGHT...BOTH THERMAL BELTS AND URBAN HEAT ISLANDS ARE LIKELY TO
BECOME STRONGER. THIS WAS REFLECTED IN OVERNIGHT LOW TRENDS IN THE
FORECAST. FRIES
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AN INTERESTING TREND HAS DEVELOPED AMONGST THE GUIDANCE WITH
RESPECT TO THE BREAKDOWN OF THE THE RIDGE AS A DEEP UPPER LOW
MOVES EASTWARD AND LIFTS INTO THE GREAT LAKES. PREVIOUS MODEL
GUIDANCE HAD LARGELY BLASTED THIS FEATURE RIGHT THROUGH OUR
REGION. MORE RECENT GUIDANCE CONTINUES TO FAVOR A MORE NORTHERLY
TRACK OF IT...WITH ONLY SHORT WAVE SUPPORT FOR ASCENT AND A MUCH
WEAKER MOISTURE FIELD TRANSITING THE AREA LARGELY MONDAY NIGHT.
POPS CONTINUE TO BE FOCUSED ON THIS PERIOD...HOWEVER THE DRY
PERIOD BEFORE AND AFTER ITS PASSAGE HAVE BEEN BOTH LENGTHENED.
BEHIND THE SHORT WAVE TROUGH MONDAY NIGHT...MODEL GUIDANCE
CONTINUES TO FAVOR BROAD TROUGHING BECOMING ESTABLISHED OVER THE
EASTERN CONUS WITH A RIDGE SETTING UP OVER THE FRONT RANGE OF THE
ROCKIES. WITH THE JET AXIS LARGELY TO OUR SOUTH...MOISTURE FLOW
TOWARD THE AREA WILL BE CUT OFF AND DRY CANADIAN AIR WILL LARGELY
BE IN CHARGE. THIS WILL MEAN BELOW NORMAL TEMPERATURES...AND MORE
SUN THAN CLOUDS. IT STILL REMAINS POSSIBLE THAT SOME FROSTS COULD
OCCUR IN SOME LOCATIONS BY THE END OF THE WEEK. FRIES
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED AGAIN DURING THE DAY TODAY WITH MID-LEVEL
CU EXPECTED. ANY SHOWERS OR THUNDERSTORMS ARE EXPECTED TO BE
CONFINED TO THE HIGH TERRAIN OF MD/WV.
TAX
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
NEXT CHANCE FOR WIDESPREAD RESTRICTIONS WILL BE MONDAY WITH AN
APPROACHING COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
519 AM EDT FRI MAY 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE MID-ATLANTIC THROUGH SATURDAY.
SUBTROPICAL STORM ANA WILL SLOWLY APPROACH THE CAROLINA COAST THIS
WEEKEND BEFORE EJECTING NORTHEAST MONDAY. A COLD FRONT LOOKS TO
MOVE INTO THE REGION TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIPRES RDG ACRS THE CWFA ATTM...WHICH SHUD REMAIN IN PLACE THRUT THE
DAY. WITH LTL WIND UNDER THE RDG...AREAS OF FOG HV BEEN ABLE TO DVLP
WHERE SKIES ARE CLR. FORTUNATELY...THE GRND NOT WET FM PRVS RAIN AS
IT WAS YDA. IN ADDITION...IN THE ELY FLOW TO THE N OF SUBRTROP
STORM ANA...A MARINE LYR IS ADVCG INLAND. THUS FAR IT REMAINS ACRS
THE DELMARVA. THERE IS A CONCERN WHETHER IT CAN CROSS THE BAY
BEFORE SUNRISE. PREV RUNS OF THE HRRR WERE THE MOST AGGRESSIVE
MDL IN THE BUNCH...SUGGESTING THE WRN EDGE OF DENSE FOG WL REACH
I-95. THE MOST RECENT RUNS HV BACKED OFF.
OBS AS OF 4 AND 5AM INDICATING THE VLY FOG HAS BEEN THE BIGGER
CONCERN. HV ISSUED A DENSE FOG ADVY FOR MOST OF THE SHEN VLY /IN
THE LWX CWFA/ AS WELL AS INVOF W99...LUA...AND CJR-HWY BASED ON
OBS. ADJUSTED THE MARINE LYR TO THE WRN SHORE OF THE BAY...ALTHO
HV SOME REDUCTIONS FOR BAYSHORE CNTYS NEAR SUNRISE.
FOG SHUD BURN OFF BY MID MRNG...MAYBE A LTL LATER IF A THICK STRATUS
LYR IS REALIZED. DECENT MID LVL LAPSE RATES REMAIN ACRS THE MTNS.
THAT/LL BE THE ONLY PLACE WHERE POPS WL BE PLACED...20-30 PCT FOR
SHRA /MAYBE A TSRA/. SCT CU ELSW.
TEMPS HV BEEN A PINCH WARMER THAN GDNC OF LATE...SO WENT A DEGF
OR TWO ABV WARMER MAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ANY PCPN WL END WITH THE SETTING SUN. DONT SEE ANY FORCING FOR THE
REST OF THE NGT. GIVEN A SIMLR SETUP...NOCTURNAL FOG WL BE THE
PRIMARY CONCERN. GDNC HITTING THE INLAND MARINE LYR ADVECTION HARDER
THAN THIS MRNG. SINCE THERE SHUD BE A BIT MORE LLVL MSTR/SLGTLY HIER
DEWPTS...HV ACCEPTED THIS SOLN IN PREMISE BUT NOT IN PRECISE OUTPUT.
THAT IS...DO NOT HV VSBYS AS LOW AS MDLS SUGGESTING BUT DO HV AREAS
OF FOG IN GRIDS.
BY SAT...ALTHO ANA SHUDNT MV MUCH...GDNC SUGGESTING THAT DEWPTS WL
BE INCRSG...AND SOME PATCHY/LGT QPF PSBL. BELIEVE THAT THE DAY WL BE
CLOUDIER...AND AM OFFERING UP PTSUN SKIES. LOW CONFIDENCE ON ACTUAL
PCPN. LIKE PREMISE OF SOMETHING IN DATABASE...AND WL CARRY ALONG
SCHC POPS FOR APPROX BLURDG EAST FOR THE AFTN INTO THE ELY EVNG HRS.
WL ATTEMPT TO KEEP SAT OVNGT DRY. CUD BE ANOTHR FOG SITUATION LT SAT
NGT AS ONSHORE FLOW WL CONT...BUT WL HOLD OFF ON PLACING THAT INTO
DATABASE AT THIS JUNCTURE.
LIKE FRI...WENT ON THE HIER SIDE FOR MAXT. APPARENT TEMPS WL BE
WARMER TOO SINCE DEWPTS WL BE HIER...MAKING FOR A MUGGY FEEL.
OMITTED THE COOLER GDNC FROM MIN-T BLEND BOTH NIGHTS. THINK THERE
WL HIGH ENUF DEWPTS TO PREVENT SIG RADL COOLING.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE LARGE SCALE RIDGE AXIS ACROSS THE EASTERN CONUS WILL HAVE
MOVED OFF THE EAST COAST BY SUNDAY WITH SUBTROPICAL ANA MAKING
LANDFALL IN THE CAROLINAS. HIGH PRESSURE ACROSS THE MID- ATLANTIC
WILL STILL BE IN CONTROL. WINDS SHOULD BECOME PURELY OUT OF THE S
BY SUN AFTERNOON RESULTING IN A WARMER DAY WITH TEMPS IN THE MID
80S. SHOWERS AND THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON. WIND
FIELD STRENGTHENS SOME SUNDAY AS ANA APPROACHES AND GFS IS FCST
NEAR 1000 J/KG OF CAPE. THUNDERSTORMS HAVE THE POTENTIAL TO BE
STRONG BUT AT THIS TIME...WIND FIELD IS STILL WEAK SO ONLY
ISOLATED STRONG IS POSSIBLE. ACTIVITY WANES INTO THE EVENING.
SUBTROPICAL STORM ANA WILL SLOWLY MOVE INTO NC MONDAY AND SOUTHERLY
WINDS WILL INCREASE ACROSS THE REGION. AT THIS TIME...THERE IS A 5
PERCENT CHANCE OF TROPICAL STORM FORCE WINDS FROM ANA ACROSS THE MID-
ATLANTIC. AT THIS TIME...ANA WILL LIKELY BECOME A DEPRESSION AS IT
WEAKENS OVER LAND. ANA WILL MOVE OVER THE MOUTH OF THE CHESAPEAKE
BAY MONDAY NIGHT AND QUICKLY MOVE OUT TO SEA BY TUESDAY MORNING.
HEAVY RAIN SHOULD STAY WELL TO THE SOUTH OF THE REGION AND NO
HAZARDOUS IMPACTS FROM ANA ARE EXPECTED AT THIS TIME. SEE COASTAL
FLOOD SECTION BELOW.
A COLD FRONT IS THEN EXPECTED TO MOVE ACROSS THE MID-ATLANTIC REGION
TUESDAY. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AHEAD OF THE
FRONT. AT THIS TIME...ACTIVITY WILL BE NEAR I-95 TUESDAY AFTERNOON
BUT TIMING OF COLD FRONT COULD CHANGE THAT.
NW WINDS WILL USHER IN DRIER COOLER AIR MID TO LATE WEEK AS HIGH
PRESSURE MOVES INTO THE PLAINS. TEMPS WILL LIKELY BE BACK AROUND 70
DEGREES.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
FOG WL BE THE MAIN CONCERN FOR TERMINALS NOT JUST DURING THE TAF
PD...BUT BYD. ATTM...CLIMO FVRD CHO SEEING THE MOST SGFNT
RESTRICTIONS...PREDOMINANTLY AOB IFR. HV INTRODUCED LIFR IN TAF.
BROUGHT MRB DOWN TO IFR AS WELL.
AM ALSO MONITORING DENSE MARINE LYR WORKING INLAND. THINK IT/LL BE
CLOSE TO BWI/DCA BY SUNRISE...BUT NOT AFFECTING TERMINALS AS PREV
THOUGHT. HV BROUGHT VSBY FCSTS UP...MAYBE A LTL MVFR INVOF BWI AT
12Z.
ONCE MRNG FOG BURNS OFF...VFR REST OF DAY. WL HV SAME FLGT
RESTRICTION CONCERNS TNGT-TMRW MRNG. XPCT FLGT CATEGORIES TO BE
LOWER AND/OR MORE PROLONGED.
SHRA/TSRA POTENTIAL PERSISTS IN THE AFTERNOON SUNDAY-TUESDAY. SUB-
VFR CONDITIONS ARE POSSIBLE.
&&
.MARINE...
MARINE AREA UNDER A RDG...KEEPING WINDS AOB 10 KT. SIMLR PTTN WL
HOLD THRU SAT...W/ ELY FLOW GRDLY BECOMING MORE SLY.
SUBTROPICAL STORM ANA WILL APPROACH THE WATERS SUN-MON. S WINDS
WILL INCREASE SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON AND SCA
CONDITIONS ARE POSSIBLE. A COLD FRONT WILL CROSS THE WATERS
TUESDAY.
&&
.TIDES/COASTAL FLOODING...
WATER LVLS REMAINING CLOSE TO ASTRO PREDICTIONS TDA. HWVR...LVLS MAY
RISE AS SUBTROPICAL STORM ANA SPINS ACROSS THE CAROLINAS. INCREASES
MAY BE REALIZED AS SOON AS SUNDAY-MONDAY. IT IS UNCLEAR AT THIS TIME
WHETHER ANY THRESHOLDS WL BE CROSSED. IF THEY ARE...SUSPECT THAT
WUDNT HAPPEN UNTIL MONDAY AT THE EARLIEST.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR VAZ025>027-
029-051-502.
WV...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR WVZ055.
MARINE...NONE.
&&
$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...HAS
AVIATION...HAS/HTS
MARINE...HAS/HTS
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
407 AM EDT FRI MAY 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE MID-ATLANTIC THROUGH SATURDAY.
SUBTROPICAL STORM ANA WILL SLOWLY APPROACH THE CAROLINA COAST THIS
WEEKEND BEFORE EJECTING NORTHEAST MONDAY. A COLD FRONT LOOKS TO
MOVE INTO THE REGION TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIPRES RDG ACRS THE CWFA ATTM...WHICH SHUD REMAIN IN PLACE THRUT THE
DAY. WITH LTL WIND UNDER THE RDG...AREAS OF FOG HV BEEN ABLE TO DVLP
WHERE SKIES ARE CLR. FORTUNATELY...THE GRND NOT WET FM PRVS RAIN AS
IT WAS YDA...AND FOG NOT AS EXTENSIVE OR DENSE. HWVR...IN THE ELY
FLOW TO THE N OF SUBRTROP STORM ANA...A MARINE LYR IS ADVCG
INLAND. THUS FAR IT REMAINS ACRS THE DELMARVA. THERE IS A CONCERN
WHETHER IT CAN CROSS THE BAY BEFORE SUNRISE. HRRR THE MOST
AGGRESSIVE MDL IN THE BUNCH...SUGGESTING THE WRN EDGE OF DENSE FOG
WL REACH I-95. WHILE I LIKE THE PREMISE...THINK THE OUTPUT A LTL
TOO DIRE. HV SOUGHT A MODIFIED VERSION OF IT-- AREAS OF FOG /BUT
NOT DENSE/ TO I- 95 AS WELL AS FILLING IN THE CLIMO FAVORED AREAS
IN THE VA FOOTHILLS/PIEDMONT. STILL NEED TO MONITOR MTR AS THERE
IS THE POTL FOR A DENSE FOG ADVY IN THE CLIMO FVRD VLYS.
FOG SHUD BURN OFF BY MID MRNG...MAYBE A LTL LATER IF A THICK STRATUS
LYR IS REALIZED. DECENT MID LVL LAPSE RATES REMAIN ACRS THE MTNS.
THAT/LL BE THE ONLY PLACE WHERE POPS WL BE PLACED...20-30 PCT FOR
SHRA /MAYBE A TSRA/. SCT CU ELSW.
TEMPS HV BEEN A PINCH WARMER THAN GDNC OF LATE...SO WENT A DEGF
OR TWO ABV WARMER MAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ANY PCPN WL END WITH THE SETTING SUN. DONT SEE ANY FORCING FOR THE
REST OF THE NGT. GIVEN A SIMLR SETUP...NOCTURNAL FOG WL BE THE
PRIMARY CONCERN. GDNC HITTING THE INLAND MARINE LYR ADVECTION HARDER
THAN THIS MRNG. SINCE THERE SHUD BE A BIT MORE LLVL MSTR/SLGTLY HIER
DEWPTS...HV ACCEPTED THIS SOLN IN PREMISE BUT NOT IN PRECISE OUTPUT.
THAT IS...DO NOT HV VSBYS AS LOW AS MDLS SUGGESTING BUT DO HV AREAS
OF FOG IN GRIDS.
BY SAT...ALTHO ANA SHUDNT MV MUCH...GDNC SUGGESTING THAT DEWPTS WL
BE INCRSG...AND SOME PATCHY/LGT QPF PSBL. BELIEVE THAT THE DAY WL BE
CLOUDIER...AND AM OFFERING UP PTSUN SKIES. LOW CONFIDENCE ON ACTUAL
PCPN. LIKE PREMISE OF SOMETHING IN DATABASE...AND WL CARRY ALONG
SCHC POPS FOR APPROX BLURDG EAST FOR THE AFTN INTO THE ELY EVNG HRS.
WL ATTEMPT TO KEEP SAT OVNGT DRY. CUD BE ANOTHR FOG SITUATION LT SAT
NGT AS ONSHORE FLOW WL CONT...BUT WL HOLD OFF ON PLACING THAT INTO
DATABASE AT THIS JUNCTURE.
LIKE FRI...WENT ON THE HIER SIDE FOR MAXT. APPARENT TEMPS WL BE
WARMER TOO SINCE DEWPTS WL BE HIER...MAKING FOR A MUGGY FEEL.
OMITTED THE COOLER GDNC FROM MIN-T BLEND BOTH NIGHTS. THINK THERE
WL HIGH ENUF DEWPTS TO PREVENT SIG RADL COOLING.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE LARGE SCALE RIDGE AXIS ACROSS THE EASTERN CONUS WILL HAVE
MOVED OFF THE EAST COAST BY SUNDAY WITH SUBTROPICAL ANA MAKING
LANDFALL IN THE CAROLINAS. HIGH PRESSURE ACROSS THE MID- ATLANTIC
WILL STILL BE IN CONTROL. WINDS SHOULD BECOME PURELY OUT OF THE S
BY SUN AFTERNOON RESULTING IN A WARMER DAY WITH TEMPS IN THE MID
80S. SHOWERS AND THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON. WIND
FIELD STRENGTHENS SOME SUNDAY AS ANA APPROACHES AND GFS IS FCST
NEAR 1000 J/KG OF CAPE. THUNDERSTORMS HAVE THE POTENTIAL TO BE
STRONG BUT AT THIS TIME...WIND FIELD IS STILL WEAK SO ONLY
ISOLATED STRONG IS POSSIBLE. ACTIVITY WANES INTO THE EVENING.
SUBTROPICAL STORM ANA WILL SLOWLY MOVE INTO NC MONDAY AND SOUTHERLY
WINDS WILL INCREASE ACROSS THE REGION. AT THIS TIME...THERE IS A 5
PERCENT CHANCE OF TROPICAL STORM FORCE WINDS FROM ANA ACROSS THE MID-
ATLANTIC. AT THIS TIME...ANA WILL LIKELY BECOME A DEPRESSION AS IT
WEAKENS OVER LAND. ANA WILL MOVE OVER THE MOUTH OF THE CHESAPEAKE
BAY MONDAY NIGHT AND QUICKLY MOVE OUT TO SEA BY TUESDAY MORNING.
HEAVY RAIN SHOULD STAY WELL TO THE SOUTH OF THE REGION AND NO
HAZARDOUS IMPACTS FROM ANA ARE EXPECTED AT THIS TIME. SEE COASTAL
FLOOD SECTION BELOW.
A COLD FRONT IS THEN EXPECTED TO MOVE ACROSS THE MID-ATLANTIC REGION
TUESDAY. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AHEAD OF THE
FRONT. AT THIS TIME...ACTIVITY WILL BE NEAR I-95 TUESDAY AFTERNOON
BUT TIMING OF COLD FRONT COULD CHANGE THAT.
NW WINDS WILL USHER IN DRIER COOLER AIR MID TO LATE WEEK AS HIGH
PRESSURE MOVES INTO THE PLAINS. TEMPS WILL LIKELY BE BACK AROUND 70
DEGREES.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
FOG WL BE THE MAIN CONCERN FOR TERMINALS NOT JUST DURING THE TAF
PD...BUT BYD. ATTM...CLIMO FVRD CHO SEEING THE MOST SGFNT
RESTRICTIONS...SPORADICALLY AOB IFR. AT THIS POINT...HV LIMITED
VSBYS TO IFR IN FCST...AND WL ONLY GO LWR IF OBSVD TRENDS DICTATE.
AM KEEPING MRB AT MVFR GIVEN HIGH CLDS INHIBITING FOG FORMATION.
AM ALSO MONITORING DENSE MARINE LYR WORKING INLAND. THINK IT/LL BE
CLOSE TO BWI/DCA BY SUNRISE. HV TAKEN IFR RESTRICTIONS TO BWI...BUT
NOT TO DCA. CONFIDENCE ON THIS SOLN NOT HIGH...AND MARGIN OF ERROR
ADMITTEDLY HUGE. WL AMD IF NEEDED.
ONCE MRNG FOG BURNS OFF...VFR REST OF DAY. WL HV SAME FLGT
RESTRICTION CONCERNS TNGT-TMRW MRNG. XPCT FLGT CATEGORIES TO BE
LOWER.
SHRA/TSRA POTENTIAL PERSISTS IN THE AFTERNOON SUNDAY-TUESDAY. SUB-
VFR CONDITIONS ARE POSSIBLE.
&&
.MARINE...
MARINE AREA UNDER A RDG...KEEPING WINDS AOB 10 KT. SIMLR PTTN WL
HOLD THRU SAT...W/ ELY FLOW GRDLY BECOMING MORE SLY.
SUBTROPICAL STORM ANA WILL APPROACH THE WATERS SUN-MON. S WINDS
WILL INCREASE SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON AND SCA
CONDITIONS ARE POSSIBLE. A COLD FRONT WILL CROSS THE WATERS
TUESDAY.
&&
.TIDES/COASTAL FLOODING...
WATER LVLS REMAINING CLOSE TO ASTRO PREDICTIONS TDA. HWVR...LVLS MAY
RISE AS SUBTROPICAL STORM ANA SPINS ACROSS THE CAROLINAS. INCREASES
MAY BE REALIZED AS SOON AS SUNDAY-MONDAY. IT IS UNCLEAR AT THIS TIME
WHETHER ANY THRESHOLDS WL BE CROSSED. IF THEY ARE...SUSPECT THAT
WUDNT HAPPEN UNTIL MONDAY AT THE EARLIEST.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...HAS
AVIATION...HAS/HTS
MARINE...HAS/HTS
TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
315 AM EDT FRI MAY 8 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND WITH
SCATTERED SHOWERS AND STORMS POSSIBLE EACH AFTERNOON...MAINLY OVER
THE HIGHER TERRAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT IR SATELLITE IMAGERY SHOWING A THIN VEIL OF HIGH CIRRUS
OVER THE LOWER 3/4 OF THE FORECAST AREA. THIS IS HELPING TO KEEP
TEMPERATURES FROM DROPPING OFF DRAMATICALLY EARLY THIS MORNING.
THE RESULT HAS BEEN A WIDE VARIETY OF TEMPERATURES AND EVEN MORE
VARYING DEWPOINT DEPRESSIONS. THINKING THIS TRANSLATES TO PATCHY
FOG DEVELOPMENT IN THE PRE-DAWN HOURS...SIMILAR TO THE LAST FEW
MORNINGS. ALMOST A PERSISTENCE FORECAST IN THAT REGARD...THE ONLY
DIFFERENCE BEING THE ADDITION OF HIGH CLOUDS SHOULD HELP LIMIT
SPATIAL COVERAGE AND INTENSITY.
EXPECTING TO LOSE THE HIGH CLOUDS BY MID-MORNING...LEADING TO
ANOTHER MORNING OF ABUNDANT SUNSHINE AND A QUICK WARM-UP. ALL
SIGNS POINT TO AN EVEN WARMER DAY THAN THURSDAY...AS LOW TO MID-
LEVEL TEMPERATURES PUSH EVEN HIGHER WITH THE LOW-LEVEL FLOW
VEERING TO SOUTHERLY. LATEST RAP IS CONSIDERABLY WARMER THAN THE
REST OF THE GUIDANCE WITH 850MB TEMPS NEARING 19C. THIS COMBINED
WITH SUNSHINE WOULD MEAN TEMPERATURES REACHING INTO THE 90S. AT
THIS POINT...FEEL THESE MID-LEVEL TEMPS ARE UNATTAINABLE IN THE
ABSENCE OF A STRONG WARM AIR ADVECTION SIGNAL. WILL KEEP HIGH
TEMPERATURES CLOSER TO THE WARM MET NUMBERS.
THE WARM SUMMER-LIKE AIR MASS SHOULD ONCE AGAIN GENERATE ISOLATED
OR SCATTERED SHOWERS/THUNDERSTORMS OVER THE ELEVATED HEAT SOURCE
OF THE HIGH TERRAIN. OTHERWISE...NOT CARRYING RAIN CHANCES THROUGH
TONIGHT. YET ANOTHER MILD NIGHT TONIGHT WITH TEMPERATURES EXPECTED
TO BE 10-15 DEGREES ABOVE NORMAL.
TAX
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
THE STATUS QUO IS BASICALLY MAINTAINED INTO THE SHORT TERM PERIOD
AS UPPER RIDGING REMAINS IN CONTROL OF THE AREA INTO THE EARLY
PART OF NEXT WEEK. GUIDANCE HAS LARGELY SLOWED THE APPROACH OF THE
UPPER LOW THAT HAS BEEN SITTING OVER THE INTERMOUNTAIN WEST ALL
WEEK AS IT EJECTS TOWARD THE GREAT LAKES. THIS RESULTS IN WARM
CONDITIONS PERSISTING RIGHT INTO MONDAY.
RELATIVELY CONTINUOUS SOUTHWESTERLY FLOW SHOULD KEEP HUMID
CONDITIONS IN PLACE. POOR MODEL-TO-MODEL AND RUN-TO-RUN
CONSISTENCY EXISTS WITH A WEAK SHORT WAVE TROUGH EMBEDDED IN THE
SOUTHWESTERLY FLOW ON SUNDAY. YET AGAIN WITH THE 00Z CYCLE
TONIGHT...SOME MODELS FAVOR IT...OTHERS DO NOT. BECAUSE OF THE
WARM/HUMID AIR MASS IN PLACE...INSTABILITY WILL LIKELY CONTINUE TO
BE HIGH...AND GIVEN THAT A LIFTING MECHANISM WILL BE REQUIRED TO
GENERATE MUCH IN THE WAY OF CONVECTION...CHANCE POPS FOR
SHOWERS/STORMS WERE MAINTAINED GIVEN THE POSSIBILITY OF THE WAVE
PASSAGE ON SUNDAY. OTHERWISE...A SLOWER TRANSITION EASTWARD OF
LARGE SCALE RIDGING MEANS LARGELY DRY CONDITIONS INTO EARLY NEXT
WEEK.
AS 850 MB TEMPERATURES LINGER IN THE MID TEENS...HIGHS WILL
CONTINUE TO REMAIN IN THE MID AND UPPER 80S. OVERNIGHT LOWS ALSO
LOOK TO REMAIN LARGELY IN THE 60S...THOUGH WITH EACH PASSING
NIGHT...BOTH THERMAL BELTS AND URBAN HEAT ISLANDS ARE LIKELY TO
BECOME STRONGER. THIS WAS REFLECTED IN OVERNIGHT LOW TRENDS IN THE
FORECAST. FRIES
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AN INTERESTING TREND HAS DEVELOPED AMONGST THE GUIDANCE WITH
RESPECT TO THE BREAKDOWN OF THE THE RIDGE AS A DEEP UPPER LOW
MOVES EASTWARD AND LIFTS INTO THE GREAT LAKES. PREVIOUS MODEL
GUIDANCE HAD LARGELY BLASTED THIS FEATURE RIGHT THROUGH OUR
REGION. MORE RECENT GUIDANCE CONTINUES TO FAVOR A MORE NORTHERLY
TRACK OF IT...WITH ONLY SHORT WAVE SUPPORT FOR ASCENT AND A MUCH
WEAKER MOISTURE FIELD TRANSITING THE AREA LARGELY MONDAY NIGHT.
POPS CONTINUE TO BE FOCUSED ON THIS PERIOD...HOWEVER THE DRY
PERIOD BEFORE AND AFTER ITS PASSAGE HAVE BEEN BOTH LENGTHENED.
BEHIND THE SHORT WAVE TROUGH MONDAY NIGHT...MODEL GUIDANCE
CONTINUES TO FAVOR BROAD TROUGHING BECOMING ESTABLISHED OVER THE
EASTERN CONUS WITH A RIDGE SETTING UP OVER THE FRONT RANGE OF THE
ROCKIES. WITH THE JET AXIS LARGELY TO OUR SOUTH...MOISTURE FLOW
TOWARD THE AREA WILL BE CUT OFF AND DRY CANADIAN AIR WILL LARGELY
BE IN CHARGE. THIS WILL MEAN BELOW NORMAL TEMPERATURES...AND MORE
SUN THAN CLOUDS. IT STILL REMAINS POSSIBLE THAT SOME FROSTS COULD
OCCUR IN SOME LOCATIONS BY THE END OF THE WEEK. FRIES
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
CALM WINDS AND RELATIVELY HUMID CONDITIONS COULD MEAN ANOTHER
ROUND OF PATCHY FOG DEVELOPMENT THIS MORNING. THE PRIMARY
ISSUE...HOWEVER...IS THE ADDITION OF HIGH CIRRUS IS KEEPING
DEWPOINT SPREADS ELEVATED THIS MORNING. CURRENT THINKING IS THAT
THESE DEWPOINT SPREADS WILL KEEP ANY FOG DEVELOPMENT LIMITED
SPATIALLY AND IN INTENSITY EVEN MORE SO THAN THE LAST FEW
MORNINGS.
VFR CONDITIONS EXPECTED AGAIN DURING THE DAY TODAY WITH MID-LEVEL
CU FIELD EXPECTED. ANY SHOWERS OR THUNDERSTORMS ARE EXPECTED TO BE
CONFINED TO THE HIGH TERRAIN OF MD/WV.
TAX
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
NEXT CHANCE FOR WIDESPREAD RESTRICTIONS WILL BE MONDAY WITH AN
APPROACHING COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
227 AM EDT FRI MAY 8 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND WITH
SCATTERED SHOWERS AND STORMS POSSIBLE EACH AFTERNOON...MAINLY OVER
THE HIGHER TERRAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT IR SATELLITE IMAGERY SHOWING A THIN VEIL OF HIGH CIRRUS
OVER THE LOWER 3/4 OF THE FORECAST AREA. THIS IS HELPING TO KEEP
TEMPERATURES FROM DROPPING OFF DRAMATICALLY EARLY THIS MORNING.
THE RESULT HAS BEEN A WIDE VARIETY OF TEMPERATURES AND EVEN MORE
VARYING DEWPOINT DEPRESSIONS. THINKING THIS TRANSLATES TO PATCHY
FOG DEVELOPMENT IN THE PRE-DAWN HOURS...SIMILAR TO THE LAST FEW
MORNINGS. ALMOST A PERSISTENCE FORECAST IN THAT REGARD...THE ONLY
DIFFERENCE BEING THE ADDITION OF HIGH CLOUDS SHOULD HELP LIMIT
SPATIAL COVERAGE AND INTENSITY.
EXPECTING TO LOSE THE HIGH CLOUDS BY MID-MORNING...LEADING TO
ANOTHER MORNING OF ABUNDANT SUNSHINE AND A QUICK WARM-UP. ALL
SIGNS POINT TO AN EVEN WARMER DAY THAN THURSDAY...AS LOW TO MID-
LEVEL TEMPERATURES PUSH EVEN HIGHER WITH THE LOW-LEVEL FLOW
VEERING TO SOUTHERLY. LATEST RAP IS CONSIDERABLY WARMER THAN THE
REST OF THE GUIDANCE WITH 850MB TEMPS NEARING 19C. THIS COMBINED
WITH SUNSHINE WOULD MEAN TEMPERATURES REACHING INTO THE 90S. AT
THIS POINT...FEEL THESE MID-LEVEL TEMPS ARE UNATTAINABLE IN THE
ABSENCE OF A STRONG WARM AIR ADVECTION SIGNAL. WILL KEEP HIGH
TEMPERATURES CLOSER TO THE WARM MET NUMBERS.
THE WARM SUMMER-LIKE AIRMASS SHOULD ONCE AGAIN GENERATE ISOLATED
OR SCATTERED SHOWERS/THUNDERSTORMS OVER THE ELEVATED HEAT SOURCE
OF THE HIGH TERRAIN. OTHERWISE...NOT CARRYING RAIN CHANCES THROUGH
TONIGHT. YET ANOTHER MILD NIGHT TONIGHT WITH TEMPERATURES EXPECTED
TO BE 10-15 DEGREES ABOVE NORMAL.
TAX
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
LARGE SCALE PATTERN LOOKS TO STAY RATHER STAGNANT THROUGH THE
PERIOD AS RIDGE REMAINS OVERHEAD. SOUTHWESTERLY FLOW WILL
MAINTAIN VERY WARM TEMPERATURES FOR THIS TIME OF YEAR...WITH LOW
TO MID 80`S EXPECTED THROUGH THE WEEKEND.
THE AFOREMENTIONED SOUTHERLY FLOW WILL CONTRIBUTE TO AN
INCREASINGLY HUMID AIRMASS. HOWEVER...DESPITE MODEST INSTABILITY
FOR DIURNAL SHOWERS AND STORMS...THERE IS LITTLE IN THE WAY OF A
LIFTING MECHANISM OR SHEAR FOR WIDESPREAD THUNDERSTORM
DEVELOPMENT. AN APPROACHING BOUNDARY AND SHORTWAVE MAY BRING THE
BEST CHANCE FOR PRECIPITATION LATER SUNDAY AFTERNOON BUT AT THIS
POINT...THE BOUNDARY ITSELF MAY STAY NORTH OF THE FORECAST AREA.
WILL CARRY CHANCE POPS THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
UPPER LEVEL RIDGE BREAKS DOWN MONDAY AS A FAIRLY STRONG UPPER
LEVEL TROUGH MOVES INTO THE NORTHERN PLAINS. ASSOCIATED COLD
FRONT MOVES EAST ACROSS THE REGION MONDAY NIGHT INTO EARLY
TUESDAY WITH SHOWERS AND STORMS. MUCH COOLER INTO MID WEEK AS
UPPER TROUGH MOVES ACROSS EASTERN CANADA AND LARGE SURFACE HIGH
SLOWLY SINKS SOUTHEAST FROM THE GREAT LAKES. PREVIOUS FORECAST
UNCHANGED AND IN GOOD OVERALL AGREEMENT WITH WPC PROGS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
CALM WINDS AND RELATIVELY HUMID CONDITIONS COULD MEAN ANOTHER
ROUND OF PATCHY FOG DEVELOPMENT THIS MORNING. THE PRIMARY
ISSUE...HOWEVER...IS THE ADDITION OF HIGH CIRRUS IS KEEPING
DEWPOINT SPREADS ELEVATED THIS MORNING. CURRENT THINKING IS THAT
THESE DEWPOINT SPREADS WILL KEEP ANY FOG DEVELOPMENT LIMITED
SPATIALLY AND IN INTENSITY EVEN MORE SO THAN THE LAST FEW
MORNINGS.
VFR CONDITIONS EXPECTED AGAIN DURING THE DAY TODAY WITH MID-LEVEL
CU FIELD EXPECTED. ANY SHOWERS OR THUNDERSTORMS ARE EXPECTED TO BE
CONFINED TO THE HIGH TERRAIN OF MD/WV.
TAX
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
NEXT CHANCE FOR WIDESPREAD RESTRICTIONS WILL BE MONDAY WITH AN
APPROACHING COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
720 PM EDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM EDT SAT MAY 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG
THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY
TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM
PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL
LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4
CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST
AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY
SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE
FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER
MI WHERE STRONGEST UPSLOPE IS OCCURRING.
FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND
THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA
WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES.
OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE
HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS
FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS
DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL
FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE
FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST
WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A
RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT...
ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES
ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD.
TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF
LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE
AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE
FLOW CONTINUES.
IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE
A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE
TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH
SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM
MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING
CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF
THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP
LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA
COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS
REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC
POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST...
RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR...
50S INLAND. MAY REACH 60F IN A FEW SPOTS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM EDT SAT MAY 9 2015
RAIN ASSOCIATED WITH AN UPPER SHORTWAVE AND SFC LOW WILL MOVE INTO
THE AREA FROM THE SW SUN NIGHT AND CONTINUE INTO MON. AS THE SFC LOW
SHIFTS ACROSS THE AREA MON EVENING INTO MON NIGHT...SHIFTING A DRY
SLOT ACROSS MOST OF THE CWA. THIS WILL DIMINISH THE RAIN UNTIL
MOISTURE MOVES BACK IN FROM THE W ON THE BACK SIDE OF THE SYSTEM
LATE MON NIGHT INTO TUE. MUCH COLDER AIR SURGES IN ON TUE WITH 850MB
TEMPS DROPPING TO AROUND -15C OVER AT LEAST NWRN UPPER MI BY 00Z
WED. THIS WILL SUPPORT A CHANGE OVER TO MIXED PRECIP OVER THE
NRN/NWRN PORTIONS OF UPPER MI ON TUE AND MOSTLY SNOW TUE NIGHT. THE
FORCING TUE INTO TUE NIGHT WILL COME FROM BOTH THE WRAP AROUND FROM
THE LOW AND FROM A WEAK SHORTWAVE MOVING IN FROM THE NW...WITH ONLY
LIGHT PRECIP EXPECTED AND LITTLE TO NO SNOW ACCUMULATION.
MON WILL SEE HIGHS IN THE 50S INLAND FROM LAKE SUPERIOR AND IN THE
40S ALONG THE BIG LAKE. TUE LOOKS TO BE THE COLDEST DAY OF THE WEEK
WITH HIGHS BARELY REACHING 50F OVER THE SCENTRAL AND IN THE 40S
ELSEWHERE. IT WILL ALSO BE CLOUDY AND BREEZY MAKING IT FEEL EVEN
COLDER. TEMPS WILL BE TRICKY TUE NIGHT AS CLOUDS WILL BE CLEARING
AND THE COLDER AIRMASS REMAINS. SHOULD SEE LOWS NEAR OR BELOW
FREEZING WITH THE CURRENT EXPECTATION OF CLOUDS CLEARING BY SUNRISE
WED...BUT MUCH COLDER TEMPS ARE POSSIBLE IF THE CLOUDS CLEAR EARLIER.
THE AIRMASS WILL BEGIN TO MODERATE ON WED AS 850MB TEMPS INCREASE TO
AROUND 0C BY 00Z THU WITH A 1031MB SFC HIGH MOVING OVER THE CWA.
SHOULD BE AN OVERALL PLEASANT DAY WITH SUNNY SKIES...LIGHT WINDS AND
HIGHS IN THE 50S INLAND TO UPPER 40S RIGHT ALONG LAKE SUPERIOR.
SIGNIFICANT UNCERTAINTY EXISTS IN THE THU-SAT PORTION OF THE
FORECAST AS MODELS CONTINUITY AND AGREEMENT IS POOR. THE GENERAL
IDEA IS UPPER RIDGING BUILDING INTO OR NEAR THE REGION...PROMOTING
WARMER TEMPS. RAIN CAN NOT BE RULED OUT. LET CONSENSUS OF GUIDANCE
HANDLE THIS PART OF THE FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 720 PM EDT SAT MAY 9 2015
VFR CONDITIONS DUE TO MIXING WILL LAST INTO THE EVENING AT CMX AND
SAW BEFORE LOW-LEVEL WINDS VEER TO A MORE EASTERLY UPSLOPE DIRECTION
LATER TONIGHT/SUN MORNING THAT CAUSE MVFR CIGS TO REDEVELOP AT BOTH
SITES. SAME THING WILL HAPPEN AT IWD...BUT IT WILL BE BY SUNDAY
MORNING. MVFR CONDITIONS WILL THEN LAST ALL OF SUNDAY AT ALL SITES
WITH NORTHEAST/EAST UPSLOPE FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT SAT MAY 9 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE
NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND
LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL
BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL
BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL
CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL
ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER
PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND
THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE
LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS.
ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT
SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO
E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS THRU THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ SUNDAY TO 8 PM EDT /7 PM
CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM SUNDAY TO 8 PM EDT MONDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
435 PM EDT FRI MAY 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 326 PM EDT FRI MAY 8 2015
A SFC LOW NEAR JAMES BAY IS DRAGGING A SFC TROUGH AND COLD FRONT
ACROSS THE CWA. BEHIND THE LOW IS A 1028MB HIGH OVER THE
SASKATCHEWAN/MANITOBA BORDER. THE COLD FRONT MOVING W TO E ACROSS
THE AREA IS NOW E OF IRON MOUNTAIN. THE NRN PORTION OF THE FRONT
SURGED ACROSS LAKE SUPERIOR AND HAS WRAPPED AROUND THE TERRAIN OF
THE NCENTRAL. THIS MAKES THE FRONT EXTEND FROM E OF IRON MOUNTAIN TO
NEAR WFO MQT TO GWINN AND THEN E TO N OF NEWBERRY. SHOWERS...BUT SO
FAR NO THUNDER...HAVE DEVELOPED AS THE FRONT SURGEST S-SW INTO
NCENTRAL UPPER MI...AGAINS THE LOW LEVEL FLOW. RUC DATA SUGGESTS
500J/KG OF SBCAPE HAS DEVELOPED NEAR IRON MOUNTAIN...BUT LESSER
AMOUNTS CLOSER TO 100J/KG ARE SHOWN WHERE CONVECTION COVERAGE IS
GREATER. CONVECTION MAY BE ABLE TO TAP INTO ENOUGH INSTABILITY FOR
SOME ISOLATED LIGHTNING INTO EARLY THIS EVENING. EXPECT THE PRECIP
TO DIE OUT AS THE FRONT MOVES ONTO LAKE MICHIGAN THIS EVENING AND
SBCAPE DIMINISHES.
LOW LEVEL WINDS BECOME N-NNE TONIGHT AS LOW LEVEL MOISTURE MOVES
OVER THE CENTRAL CWA. THIS WILL ALLOW LOW CLOUDS IN UPSLOPE AREAS OF
NCENTRAL AND ERN UPPER MI THAT WILL ONLY SLIGHTLY DIMINISH THROUGH
THE DAY SAT. CAN NOT RULE OUT SOME SPRINKLES OVER THE NCENTRAL SAT
MORNING...SO LEFT THOSE IN THE FORECAST. SKIES WILL BECOME PARTLY
CLOUDY INLAND WHERE HIGH TEMPERATURES WILL REACH THE UPPER 50S TO
MID 60S. NEAR LAKE SUPERIOR...HIGH TEMPS WILL BE IN THE 40S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 435 PM EDT FRI MAY 8 2015
A COOL PERIOD IS SHAPING UP FOR MOST OF THE LONG TERM WITH A DAY OR
TWO OF MUCH BLO NORMAL TEMPS EARLY NEXT WEEK. RIDGE CURRENTLY
BUILDING OVER WRN CANADA WILL FORCE DOWNSTREAM TROFFING INTO ERN
CANADA THRU THE MIDDLE OF NEXT WEEK. BOTH FEATURES WILL THEN BEGIN
TO WEAKEN AFTER MIDWEEK. THIS WILL RESULT IN THE ESTABLISHMENT OF A
LARGE POOL OF COLD AIR JUST TO THE N AND NE OF HERE OVER THE NEXT
SEVERAL DAYS. MEANWHILE...CLOSED MID LEVEL LOW OVER THE SW CONUS IS
EXPECTED TO OPEN UP AS IT LIFTS NE INTO THE GREAT LAKES REGION EARLY
NEXT WEEK. WITH THE ASSOCIATED SFC LOW LIKELY TRACKING BY JUST S OF
UPPER MI...LOW-LEVEL NE WINDS WILL KEEP A SHALLOW TAP FROM THE COLD
AIR TO THE N AND NE....AND THEN AS THE LOW PASSES BY...THE COLD AIR
WILL DUMP INTO THE AREA THRU THE MIDDLE OF NEXT WEEK. THEREAFTER...
RISING HEIGHTS OVER THE WRN LAKES AS THE ERN CANADA TROF LIFTS NE
WILL SPELL A WARMING TREND LATE NEXT WEEK. AS FOR PCPN...THE
AFOREMENTIONED SYSTEM MOVING INTO THE GREAT LAKES REGION EARLY NEXT
WEEK SHOULD BRING A MUCH NEEDED WIDESPREAD RAINFALL TO UPPER MI SUN
THRU TUE...WITH THE SUN NIGHT/MON TIME FRAME LIKELY TO SEE THE BULK
OF THE RAINFALL. WITH THE COLD AIR FOLLOWING THE SYSTEM...SOME AREAS
WILL LIKELY SEE A LITTLE SNOW AS WELL. DRY WEATHER SHOULD THEN BE
THE RULE FOR THE LAST HALF OF THE WORK WEEK.
BEGINNING SAT NIGHT...SFC HIGH PRES WILL BE SETUP ACROSS
MANITOBA/NRN ONTARIO WHILE SFC LOW PRES BEGINS TO LIFT NE OUT OF THE
WRN HIGH PLAINS. UNCERTAINTY IN THE LOW CLOUD FCST ON SAT CARRIES
INTO SAT NIGHT...BUT WOULD THINK THAT AFTER A DAY OF EARLY MAY
DAYTIME HEATING ON SAT...LOW-LEVEL MOISTURE WOULD TEND TO MIX OUT TO
SOME DEGREE. THE NAM WHICH HAS BEEN MUCH MORE PERSISTENT IN HOLDING
LOW-LEVEL MOISTURE OVER THE AREA IS TRENDING DRIER...MORE INLINE
WITH THE GFS...SO THERE MAY NOT BE MUCH STRATOCU TO CONTEND WITH SAT
NIGHT. HIGHER UP...SOME HIGH CLOUDINESS WILL BEGIN TO SPREAD INTO
THE AREA.
ON SUN...MODELS SHOW A WEAK LEAD SHORTWAVE TROF LIFTING INTO THE
UPPER GREAT LAKES WELL IN ADVANCE OF THE MID LEVEL LOW WHICH WILL BE
MOVING TO NEBRASKA/SD. GOOD SURGE OF 700MB MOISTURE TRANSPORT AND
DECENT ISENTROPIC ASCENT SHOULD SUPPORT AT LEAST SCT SHRA SPREADING
NE INTO THE FCST AREA DURING THE DAY. BEST CHC WILL BE OVER THE W
WHERE MORE SUSTAINED FORCING IS INDICATED.
SUN NIGHT THRU MON NIGHT...MID LEVEL LOW OVER NEBRASKA/SD SUN
EVENING WILL OPEN UP AND MOVE TO THE WRN GREAT LAKES. ASSSOCIATED
SFC LOW SHOULD MOVE ACROSS SRN MN INTO NRN WI AND THEN TO VCNTY OF
THE STRAITS. THERE HAS BEEN A TREND FROM MANY OF THE MODELS FOR A
SLIGHTLY FARTHER N TRACK SO THAT THE SFC LOW PASSES ACROSS SRN AND
ERN UPPER MI LATE MON AFTN/MON EVENING. THE TRACK OF THESE FEATURES
AND ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW/PRECIPITABLE
WATER AOA 1 INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RAIN. IF
THE TREND FOR A FARTHER N LOW TRACK IS VALID...BREAKS IN THE PCPN
WOULD BE MORE LIKELY...ESPECIALLY ACROSS THE S. ON THE OTHER
HAND...IF THE LOW TRACK IS FARTHER S...MORE PERSISTENT PCPN WILL
OCCUR. AT THIS POINT...LOOKS LIKE WIDESPREAD PCPN AMOUNTS IN THE 0.5
TO 1 INCH RANGE ARE LIKELY SUN NIGHT/MON. MAINTAINED A MENTION OF
SCHC THUNDER OVER THE SCNTRL SUN NGT INTO MON INLIGHT OF THE
POTENTIAL FARTHER N LOW TRACK AND ELEVATED INSTABILITY THAT PUSHES
INTO THE AREA ON THE MODELS WITH THE FARTHER N TRACK. AS THE LOW
TRACKS TO AROUND THE STRAITS MON NIGHT...THE STEADIER/HEAVIER PCPN
WILL EXIT TO THE E. HOWEVER...MORE PERSISTENT LIGHT PCPN WILL
LINGER...MAINLY ACROSS THE N. AS COLDER AIR BEGINS TO SPREAD S
BEHIND THE LOW (850MB TEMPS AS LOW AS AROUND -2C LATE MON NIGHT)...
SNOW MAY BEGIN TO MIX WITH THE RAIN OVER THE HIGH TERRAIN OF THE W.
WITH 850MB TEMPS FALLING TO -3C TO AS LOW AS -6C TUE...LINGERING
LIGHT RAIN WILL BE MORE LIKELY TO MIX WITH SNOW...ESPECIALLY OVER
THE HIGH TERRAIN OF THE W AND NCNTRL BEFORE THE ARRIVAL OF MORE
ANTICYCLONIC FLOW/DRIER AIR CAUSES THE PCPN TO DIMINISH LATER IN THE
DAY. DAYTIME INSOLATION WILL CERAINLY LIMIT THE POTENTAIL FOR MUCH
IF ANY SNOW ACCUMULATION...EXCEPT PERHAPS ON GRASSY SFCS.
DRY/COOL WEATHER WILL FOLLOW FOR WED AS SFC HIGH PRES BUILDS INTO
THE UPPER LAKES.
THU/FRI...RELIED MORE ON THE ENSEMBLES DUE TO RATHER SIGNIFICANT
UNCERTAINTY IN THE LATE WEEK FLOW PATTERN OVER N AMERICA. WHILE THE
GFS MAINTAINS MORE TROFFING IN ERN CANADA (SLOWER RELAXING OF NW
FLOW FOR THE UPPER LAKES)...THE ECMWF SHOWS QUICKER DEPARTURE OF THE
TROF WHICH ALLOWS FOR ANOTHER DISTURBANCE TO MOVE OUT OF THE ROCKIES
AND REACH THE GREAT LAKES THU NIGHT. THE ENSEMBLE APPROACH RESULTS
IN RIDGING DEVELOPING OVER THE MISSISSIPPI VALLEY AND CONNECTING UP
WITH THE WEAKENING WRN CANADA RIDGE. IN TURN...THIS CAUSES MORE
PERSISTENT SFC HIGH PRES LINGERING OVER THE GREAT LAKES REGION...AND
THUS DRY WEATHER LIKELY PREVAILING FOR THE LAST HALF OF THE WORK
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 138 PM EDT FRI MAY 8 2015
AT KIWD AND KCMX...A COLD FRONT MOVED THROUGH EARLIER...BRINGING
LOWERED CIGS. CONDITIONS WILL IMPROVE AS LOW LEVEL MOISTURE
DECREASES.
AT KSAW...THE COLD FRONT MOVED THROUGH SHORTLY BEFORE 18Z...BRINGING
NE WINDS OFF LAKE SUPERIOR AND SHOULD RESULT IN SOME DECREASED CIGS
THIS EVENING BEFORE SOME IMPROVEMENT EARLY TONIGHT. AN AREA OF LOW
LEVEL MOISTURE WILL MOVE INTO THE AREA WITH N-NNE WINDS LATE TONIGHT
AND SAT MORNING...RESULTING IN REDUCED CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT FRI MAY 8 2015
SW-NW WINDS BEHIND A COLD FRONT THAT MOVED THROUGH TODAY WILL
DIMINISH SOME THIS EVENING INTO TONIGHT AND REMAIN BELOW 20KTS
THROUGH SAT NIGHT. AS LOW PRESSURE SLIDES FROM THE CENTRAL PLAINS TO
THE UPPER LAKES FROM SUNDAY INTO MONDAY...NORTH TO NORTHEAST WINDS
OF 20 TO 30 KNOTS ARE EXPECTED TO DEVELOP...ESPECIALLY OVER THE
WEST. GALE FORCE GUSTS TO 35 KNOTS ARE EXPECTED OVER WESTERN
LAKE SUPERIOR SUNDAY NIGHT INTO MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
328 PM EDT FRI MAY 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 326 PM EDT FRI MAY 8 2015
A SFC LOW NEAR JAMES BAY IS DRAGGING A SFC TROUGH AND COLD FRONT
ACROSS THE CWA. BEHIND THE LOW IS A 1028MB HIGH OVER THE
SASKATCHEWAN/MANITOBA BORDER. THE COLD FRONT MOVING W TO E ACROSS
THE AREA IS NOW E OF IRON MOUNTAIN. THE NRN PORTION OF THE FRONT
SURGED ACROSS LAKE SUPERIOR AND HAS WRAPPED AROUND THE TERRAIN OF
THE NCENTRAL. THIS MAKES THE FRONT EXTEND FROM E OF IRON MOUNTAIN TO
NEAR WFO MQT TO GWINN AND THEN E TO N OF NEWBERRY. SHOWERS...BUT SO
FAR NO THUNDER...HAVE DEVELOPED AS THE FRONT SURGEST S-SW INTO
NCENTRAL UPPER MI...AGAINS THE LOW LEVEL FLOW. RUC DATA SUGGESTS
500J/KG OF SBCAPE HAS DEVELOPED NEAR IRON MOUNTAIN...BUT LESSER
AMOUNTS CLOSER TO 100J/KG ARE SHOWN WHERE CONVECTION COVERAGE IS
GREATER. CONVECTION MAY BE ABLE TO TAP INTO ENOUGH INSTABILITY FOR
SOME ISOLATED LIGHTNING INTO EARLY THIS EVENING. EXPECT THE PRECIP
TO DIE OUT AS THE FRONT MOVES ONTO LAKE MICHIGAN THIS EVENING AND
SBCAPE DIMINISHES.
LOW LEVEL WINDS BECOME N-NNE TONIGHT AS LOW LEVEL MOISTURE MOVES
OVER THE CENTRAL CWA. THIS WILL ALLOW LOW CLOUDS IN UPSLOPE AREAS OF
NCENTRAL AND ERN UPPER MI THAT WILL ONLY SLIGHTLY DIMINISH THROUGH
THE DAY SAT. CAN NOT RULE OUT SOME SPRINKLES OVER THE NCENTRAL SAT
MORNING...SO LEFT THOSE IN THE FORECAST. SKIES WILL BECOME PARTLY
CLOUDY INLAND WHERE HIGH TEMPERATURES WILL REACH THE UPPER 50S TO
MID 60S. NEAR LAKE SUPERIOR...HIGH TEMPS WILL BE IN THE 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 410 AM EDT FRI MAY 8 2015
MAIN FCST CONCERNS IN THE LONGER TERM FOCUS ON COVERAGE OF LO CLDS
ON SAT/SAT NGT AND THEN THE POTENTIAL FOR A WELCOME WDSPRD PCPN
EVENT EARLY NEXT WEEK AS THE CLOSED LO NOW OVER THE DESERT SW AND
ACCOMPANYING SFC LO PRES LIFT NE TOWARD THE UPR LKS. MUCH COOLER WX
WL DOMINATE UPR MI DURING MOST OF THE LONGER TERM.
SAT...SINCE THE UPR FLOW IS FCST TO REMAIN SW BTWN MEAN RDG OVER THE
SE CONUS AND GENERAL TROFFING IN CENTRAL NAMERICA...THE COLD FNT
ASSOCIATED WITH DEPARTING SFC LO IN QUEBEC IS PROGGED TO STALL OVER
THE LOWER GRT LKS. SOME RECENT MODEL RUNS HAVE SHOWN A LO PRES
RIDING ALONG THIS BNDRY AND BRINGING SOME PCPN TO MAINLY THE SE
CWA...BUT THE BULK OF THE LATEST RUNS NOW INDICATE THIS LO/PCPN WL
REMAIN TO THE SE OF UPR MI. DESPITE THE MORE AGGRESSIVE MID LVL
DRYING...LINGERING LLVL MSTR IN NE FLOW ON THE SE FLANK OF SFC HI
PRES OVER SCENTRAL CANADA WL LIKELY BRING SOME LO CLDS OVER THE
NCENTRAL AND E. PER THE 00Z NAM/CNDN FCST...DID MAINTAIN A MENTION
OF SOME SPRINKLES OVER THE NCENTRAL WHERE UPSLOPE WIND COMPONENT WL
BE MAXIMIZED. WITH LLVL NE FLOW OFF THE CHILLY LK WATERS...HI TEMPS
NEAR LK SUP IN THIS AREA WL BE HARD PRESSED TO GET OUT OF THE 40S.
WITH MORE SUNSHINE OVER THE W AND SCENTRAL...HI TEMPS SHOULD APRCH
60 WITH MIXING TO H85 ON FCST SDNGS.
SAT NGT...HI PRES IN SCENTRAL CANADA IS FCST TO DRIFT SLOWLY E INTO
FAR NW ONTARIO WHILE CLOSED LO LIFTING OUT OF THE DESERT SW CAUSES
SFC LO PRES IN THE CENTRAL PLAINS TO BEGIN SHIFTING NEWD. AS THE
LLVL FLOW OVER THE UPR LKS BEGINS TO VEER A BIT IN THE PRESENCE OF
NOCTURNAL COOLING...THE SC IMPACTING THE NCENTRAL AND E MAY TEND TO
DRIFT TOWARD THE W AND OVERSPREAD ALL BUT THE W WHERE THE LLVL ENE
FLOW DOWNSLOPES BY 12Z SUN. SOME HI CLDS WELL IN ADVANCE OF THE
CLOSED LO/SFC LO PRES MAY REACH THE WRN CWA BY DAYBREAK ON SUN.
SUN...ALTHOUGH CONTINUED VEERING LLVL FLOW TOWARD THE E WOULD ALLOW
FOR SOME LLVL MSTR/AT LEAST BKN LO CLDS TO IMPACT MUCH OF THE CWA...
SOME OF THE MODELS SHOW SOME LLVL DRYING ON THE SRN FLANK OF THE HI
IN FAR NW ONTARIO SUFFICIENT TO BREAK UP THIS CLD EXCEPT OVER THE
SCNTRAL. EVEN IF/WHERE THIS SC IS ABSENT...MID/HI CLDS WL BE INCRSG
IN DIFFLUENT UPR FLOW/INCRSG ISENTROPIC ASCENT IN ADVANCE OF CLOSED
LO MOVING NEWD THRU THE PLAINS. WITH ARRIVAL OF MORE VIGOROUS DEEP
LYR QVECTOR CNVGC/UPR DVGC IN THE AFTN...MOST OF THE MODELS DO
GENERATE SOME PCPN OVER AT LEAST THE WRN CWA IN THE AFTN...SO WL
MAINTAIN FCST HIER CHC POPS IN THAT AREA.
SUN NGT THRU TUE...AS NEGATIVELTY TILTED CLOSED LO OPENS UP AND
LIFTS ENEWD INTO THE UPR LKS BY TUE...SFC LO PRES IS PROGGED TO MOVE
ENEWD FM SE SDAKOTA ON SUN EVNG INTO WI BY LATE MON AND THEN INTO SE
ONTARIO BY TUE MRNG. THE TRACK OF THESE FEATURES AND ACCOMPANYING
DYNAMIC FORCING/DIFFLUENT UPR FLOW/DEEP CYC FLOW/PWAT AOA 1 INCH
INDICATE THERE WL BE AT LEAST PERIODS OF RA. IF THE UPR LO DRIFTS A
BIT FARTHER TO THE N...BREAKS IN THE PCPN WOULD BE MORE LIKELY
ESPECIALLY OVER THE SRN TIER. ON THE OTHER HAND...IF THE UPR LO
TRACKS A BIT FARTHER TO THE S...A MORE PERSISTENT CCB WOULD BRING
ABOUT MORE CONTINUOUS PCPN. THE LATEST CPC HAZARDS CHART INDICATES A
POTENTIAL FOR SOME HEAVY RA OVER THE ENTIRE CWA. DID INTRODUCE A
SCHC OF TS OVER THE FAR SCENTRAL SUN NGT INTO MON AS THE 00Z ECMWF
SHOWS A BIT FARTHER N TRACK OF THE UPR LO/HIER INSTABILITY OVER THAT
AREA. AS THE SFC LO EXITS TO THE E ON TUE...THE ARRIVAL OF COLDER
AIR WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W BEFORE THE EXIT
OF THE FORCING/ARRIVAL OF MORE ACYC FLOW CAUSES THE PCPN TO DIMINISH
LATER IN THE DAY. SINCE THE COLDER AIR WL ARRIVE AFTER 12Z
TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY
SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS.
WED/THU...CONSIDERABLE MODEL DIFFERENCES BECOME APRNT DURING THIS
LATER PORTION OF THE FCST. THE 00Z GFS IS MOST AGGRESSIVE WITH
MAINTAINING A LARGER SCALE TROF/COLDER AIR THRU WED...THEN SHOWS AN
UPR RDG/DRIER AIR DOMINATING THE AREA ON THU. THE 00Z ECMWF ON THE
OTHER HAND SHOWS BUILDING HGTS MUCH FASTER ON WED...AND THEN BRINGS
ANOTHER DISTURBANCE/SOME PCPN TOWARD THE AREA ON THU. WL RELY ON THE
MODEL CONSENSUS FCST THIS FAR OUT IN THE FCST PACKAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 138 PM EDT FRI MAY 8 2015
AT KIWD AND KCMX...A COLD FRONT MOVED THROUGH EARLIER...BRINGING
LOWERED CIGS. CONDITIONS WILL IMPROVE AS LOW LEVEL MOISTURE
DECREASES.
AT KSAW...THE COLD FRONT MOVED THROUGH SHORTLY BEFORE 18Z...BRINGING
NE WINDS OFF LAKE SUPERIOR AND SHOULD RESULT IN SOME DECREASED CIGS
THIS EVENING BEFORE SOME IMPROVEMENT EARLY TONIGHT. AN AREA OF LOW
LEVEL MOISTURE WILL MOVE INTO THE AREA WITH N-NNE WINDS LATE TONIGHT
AND SAT MORNING...RESULTING IN REDUCED CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT FRI MAY 8 2015
SW-NW WINDS BEHIND A COLD FRONT THAT MOVED THROUGH TODAY WILL
DIMINISH SOME THIS EVENING INTO TONIGHT AND REMAIN BELOW 20KTS
THROUGH SAT NIGHT. AS LOW PRESSURE SLIDES FROM THE CENTRAL PLAINS TO
THE UPPER LAKES FROM SUNDAY INTO MONDAY...NORTH TO NORTHEAST WINDS
OF 20 TO 30 KNOTS ARE EXPECTED TO DEVELOP...ESPECIALLY OVER THE
WEST. GALE FORCE GUSTS TO 35 KNOTS ARE EXPECTED OVER WESTERN
LAKE SUPERIOR SUNDAY NIGHT INTO MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TITUS
LONG TERM...KC
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
200 PM EDT FRI MAY 8 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 AM EDT FRI MAY 8 2015
WARM AND UNSETTLED WEATHER CAN BE EXPECTED ACROSS THE AREA FROM
TODAY RIGHT ON THROUGH THE WEEKEND AND INTO THE DAY ON MONDAY. WAVES
OF LOW PRESSURE WILL RIDE UP ALONG A FRONT THAT WILL BE MOVING BACK
AND FORTH ACROSS THE AREA. THESE WAVES WILL KEEP A THREAT OF SHOWERS
AND STORMS IN ACROSS THE AREA THROUGH MONDAY.
A STRONGER COLD FRONT WILL MOVE THROUGH LATER ON MONDAY. THIS FRONT
WILL BRING ANOTHER ROUND OF SHOWERS AND STORMS WILL IT. MUCH COOLER
AIR WILL EVENTUALLY MOVE IN ACROSS THE AREA.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 329 AM EDT FRI MAY 8 2015
OUR MAIN FOCUS IN THE SHORT TERM IS DETERMINING TIMING OF WAVES OF
BETTER CHCS OF SHOWERS AND STORMS...AND LOOKING AT ANY KIND OF
SEVERE WEATHER THREAT. WE ARE THINKING THAT A WIDESPREAD SEVERE
THREAT LOOKS QUITE LIMITED THROUGH THE UPCOMING WEEKEND...ALTHOUGH
THERE WILL BE MULTIPLE WAVES OF SHOWERS AND A FEW STORMS.
WE WILL SEE A LITTLE BETTER CHC FOR A FEW SHOWERS AND A STORM
TODAY...COMPARED TO YESTERDAY. THE MUCH BETTER CHC WILL COME
OVERNIGHT TONIGHT INTO SAT MORNING FOR THE AREA. THE MOISTURE AXIS
HAS SHIFTED OVER THE AREA...HOWEVER IT IS IN THE PROCESS OF
WEAKENING AS IT MOVES IN. THIS IS OCCURRING AS THE BETTER LLJ IS
STAYING WELL NORTH OF THE CWFA THIS MORNING AND MOVING AWAY.
WE WILL SEE ANOTHER LLJ OF 30+ KNOTS MOVE IN OVERNIGHT TONIGHT AHEAD
OF THE NEXT SHORT WAVE. THIS IS EXPECTED TO BRING RAIN TO MUCH OF
THE AREA. THIS WILL CONTINUE INTO SAT MORNING BEFORE IT MOVES NORTH
AND EAST OF THE AREA ON SAT AFTERNOON. THIS WILL ACTUALLY DROP THE
FRONT SOUTH THROUGH THE AREA AND PROVIDE FOR A SOMEWHAT DRIER PERIOD
FOR SAT NIGHT.
THE THREAT OF SHOWERS AND STORMS WILL THEN INCREASE ONCE AGAIN
DURING THE DAY ON SUN. WE WILL SEE A STRONG MID LEVEL FLOW TAKE
SHAPE OVER THE REGION AS THE UPPER LOW STARTS TO EJECT TO THE E/NE
FROM THE DESERT SW. THIS SCENARIO WILL HELP TO PUSH THE STALLED OUT
FRONT BACK NORTH AS A WARM FRONT. A NICE SLUG OF MOISTURE TRANSPORT
WILL MOVE UP INTO THE AREA...HELPING TO FOCUS SHOWERS AND STORMS
ALONG AND AHEAD OF THE WARM FRONT.
SEVERE WEATHER IS NOT LOOKING REAL LIKELY FOR THE AREA THROUGH THE
WEEKEND. INSTABILITY FOR TODAY AND TOMORROW IS GENERALLY A FEW
HUNDRED J/KG OF CAPE WITH LI/S OF AROUND -2 TO -4C. NO REAL THICK
CAPE PROFILES TO HELP WITH LARGE HAIL. WIND FIELDS ARE GENERALLY ON
THE LIGHTER SIDE...PRODUCING DEEP LAYER SHEAR VALUES OF UNDER 25-30
KNOTS. THE WARM FRONT COMING UP ON SUN IS A LITTLE CONCERNING. DEEP
LAYER SHEAR IS A BIT BETTER ALSO ON SUN AS THE MID LEVEL JET STREAK
MOVES CLOSER TO THE STATE.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 AM EDT FRI MAY 8 2015
IT WOULD SEEM STRONG STORMS ARE STILL POSSIBLE MONDAY AS THE PRIMARY
SYSTEM COMES OUT OF THE SOUTHWESTERN UNITED STATES AND PHASES WITH
THE NORTHERN STREAM WAVE. BEYOND THAT COOLER WEATHER WILL FOLLOW AT
LEAST INTO THE END OF NEXT WEEK.
THE MODELS REMAIN IN REASONABLE AGREEMENT ON THE TRACK OF THE
SURFACE LOW WILL TRACK WELL WEST OF SOUTHWEST LOWER MICHIGAN AS IT
COMES OUT OF THE SOUTHWESTERN UNITED STATES MONDAY. THE 00Z GFS
SEEMS MORE RELUCTANT TO BRING SOUTHWEST MICHIGAN INTO THE WARM
SECTOR OF THE STORM. IF THAT TURNS OUT TO BE TRUE THE SEVERE
STORMS WOULD STAY SOUTH OF THE AREA MONDAY. STILL ALL MODELS SHOW
SOUTHWEST MICHIGAN GETS INTO THE RIGHT REAR ENTRANCE REGION TO THE
UPPER JET AS IT LIFTS NORTHWARD THROUGH WISCONSIN MONDAY
AFTERNOON. WE STILL HAVE A 50 KNOT LOW LEVEL JET OVER EASTERN
LOWER MICHIGAN BY LATE AFTERNOON...THERE IS AT LEAST 1000 J/KG OF
MOST UNSTABLE CAPE AND THERE IS 50 KNOTS OF DEEP LAYER SHEAR. IT
REMAINS A QUESTION OF JUST HOW FAR NORTH THE WARM FRONT ACTUALLY
GETS MONDAY. IT REMAINS CLEAR SEVERE WEATHER IS STILL A REAL
THREAT FOR SOUTHWEST MICHIGAN MONDAY AFTERNOON.
BEYOND THAT ALL MODELS AGREE THE COLD AIR COMES IN FOR TUESDAY
THROUGH FRIDAY. NOW THOUGH THE ECMWF SHOWS A SYSTEM LIFTING OUT OF
THE SOUTHWESTERN UNITED STATES MOVING INTO OUR AREA BY THURSDAY.
THIS SEEMS TO FAST TO ME AND THE ECMWF WAS NOT DOING THIS PREVIOULSY
SO I DID NOT ACCOUNT FOR IT IN OUR ZONE FORECAST.
WE WILL HAVE TO WATCH WHAT HAPPENS TO TYPHOON NOUL. IT SEEMS TO WANT
TO RECUVE EARLY NEXT WEEK. LAST YEAR EVERY TIME THIS HAPPENED WE AND
WELL BELOW NORMAL TEMPERATURE FOR ABOUT A WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 158 PM EDT FRI MAY 8 2015
WIDELY SCATTERED THUNDERSTORMS CAN BE EXPECTED ALONG THE I-96
REGION THROUGH THE AFTERNOON...AND COULD LINGER FOR THE I-94 AREA
INTO THE EVENING. OTHERWISE VFR CONDITIONS CAN BE EXPECTED THIS
AFTERNOON AND EVENING. SOUTHWEST WINDS WILL REMAIN AROUND 10 KTS
UNTIL EARLY EVENING.
A MORE WIDESPREAD AREA OF RAIN AND A FEW THUNDERSTORMS WILL ARRIVE
OVERNIGHT. THIS WILL BRING IN MVFR AND OCCASIONAL IFR CONDITIONS
THAT WILL LINGER INTO SATURDAY MORNING. AS FOR THE CHANCES OF
THUNDERSTORMS...THE INSTABILITY SHOULD BE GREATEST ALONG I-94
WHERE STORMS WILL BE POSSIBLE INTO THE EARLY MORNING. LEFT STORMS
OUT OF THE TAFS ALONG THE I-96 REGION ALTHOUGH SOME VERY ISOLATED
THUNDER IS POSSIBLE.
&&
.MARINE...
ISSUED AT 746 AM EDT FRI MAY 8 2015
BASED ON HIGHER DEW POINTS MOVING OVER COLD LAKE MICHIGAN WATERS
AND THE HRRR SHOWING FOG BECOMING EXTENSIVE OVER LAKE MICHIGAN
TODAY I ADDED FOG TO THE NEAR SHORE WEATHER GRIDS. CURRENT WEB
CANS DO NOT SHOW MUCH FOG YET BUT I DO BELIEVE WE WILL SEE THE FOG
DEVELOP OVER TIME.
&&
.HYDROLOGY...
ISSUED AT 111 PM EDT FRI MAY 8 2015
RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR NORMAL
FLOWS FOR THIS TIME OF YEAR...ESPECIALLY CLOSER TO THE LAKESHORE.
SOME RIVERS FURTHER INLAND ACROSS PORTIONS OF CENTRAL AND MID-
MICHIGAN ARE RUNNING SLIGHTLY BELOW NORMAL...SUCH AS THE RED CEDAR
RIVER AT EAST LANSING...THE GRAND RIVER AT IONIA...AND THE MUSKEGON
RIVER AT EVART.
RIVER LEVEL RISES ARE EXPECTED THIS WEEKEND AND WILL CONTINUE INTO
NEXT WEEK. 1-2 INCHES OF RAINFALL IS POSSIBLE TODAY THROUGH MONDAY.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN
COVERAGE AND INTENSITY THIS EVENING. MORE WIDESPREAD RAINFALL IS
EXPECTED OVERNIGHT INTO SATURDAY MORNING. MINOR FLOODING IN URBAN
AND LOW-LYING AREAS WILL BE POSSIBLE TONIGHT INTO SATURDAY. WE HAVE
A FAIRLY MOIST ATMOSPHERE IN PLACE. UPPER AIR CLIMATOLOGY
INDICATES PRECIPITABLE WATER VALUES IN EXCESS OF THE 75TH
PERCENTILE. SFC DEWPOINTS ARE IN THE LOWER 60S THIS AFTERNOON WITH
MID TO UPPER 60S NOTED IN NW INDIANA AND NE ILLINOIS. ANY
CONVECTIVE RAIN SHOWERS OR STORMS THIS WEEKEND SHOULD BE FAIRLY
EFFICIENT RAINFALL PRODUCERS.
A DRY PERIOD IS FORECAST SATURDAY AFTERNOON THROUGH SATURDAY NIGHT
BEFORE RAIN AND STORM CHANCES INCREASE AGAIN ON SUNDAY. STRONG TO
SEVERE STORMS ARE POSSIBLE MONDAY...WHICH WILL HAVE TO POTENTIAL TO
PRODUCE HEAVY RAINFALL AND MINOR FLOODING. MORE SIGNIFICANT FLOODING
COULD OCCUR IF THE SAME AREAS SEE MODERATE TO HEAVY RAINFALL FROM
STORMS THIS EVENING AND TONIGHT AS WELL AS ON SUNDAY AND MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...JK
HYDROLOGY...EBW
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
146 PM EDT FRI MAY 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT FRI MAY 8 2015
WV IMAGERY AND RUC ANALYSIS INDICATED SW MID/UPPER LEVEL FLOW FROM
THE CNTRL/SRN PLAINS THROUGH THE WRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED THROUGH FAR WRN LAKE SUPERIOR INTO WRN WI FROM
LOW PRES OVER NW ONTARIO. THE COMBINATION OF LOW LEVEL CONV NEAR THE
FRONT AND A SHORTWAVE TROUGH FROM WRN LAKE SUPERIOR INTO NW WI
SUPPORTED SCT/ISOLD SHRA INTO FAR WRN UPPER MI. WITH NIGHTTIME
COOLING...THE CONVECTION HAD WEAKENED ENOUGH SO THAT NO LIGHTNING WAS
OBSERVED OVER THE REGION.
TODAY...THE FRONT WILL CONTINUE TO PUSH TO THE EAST AS THE LOW MOVES
TOWARD JAMES BAY. MODELS AND RADAR TRENDS SUGGEST THAT SCT/ISOLD
SHRA WILL CONTINUE TO SPREAD EASTWARD THROUGH WRN UPPER MI. EXPECT
HIGHER SHRA/TSRA CHANCES OVER THE CNTRL AND EAST...ESPECIALLY DURING
THE AFTERNOON WHEN THE FRONT MOVES INTO THE AREA DURING PEAK HEATING
WITH THE POTENTIAL TO INTERACT WITH LAKE BREEZE BOUNDARIES. WITH
MLCAPE VALUES OF ONLY 400-800 J/KG AND 0-6KM SHEAR OF 30-35
KNOTS...CONDITIONS WILL MARGINAL FOR ANY STRONGER STORMS. THERE IS
ALSO STILL UNCERTAINTY WITH THE AMOUNT CLOUD COVER AND
HEATING/INSTABILITY.
TONIGHT...AFTER THE SHRA/TSRA MOVE OUT OF THE ERN CWA DURING THE
EVENING...EXPECT DRY WEATHER OVERNIGHT. THE MODELS HAVE CONTINUED
TREND OF KEEPING SHRA/TSRA DEVELOPING ALONG THE FRONT TO THE SOUTH
AND EAST OF UPPER MI. SOME LIGHT SPRINKLES OR PATCHY DRIZZLE MAY
DEVELOP LATE NORTH CENTRAL WITH LINGERING LOW LEVEL MOISTURE AND A
PERIOD OF CYCLONIC NNE FLOW ASSOCIATED WITH A WEAK SFC TROUGH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 410 AM EDT FRI MAY 8 2015
MAIN FCST CONCERNS IN THE LONGER TERM FOCUS ON COVERAGE OF LO CLDS
ON SAT/SAT NGT AND THEN THE POTENTIAL FOR A WELCOME WDSPRD PCPN
EVENT EARLY NEXT WEEK AS THE CLOSED LO NOW OVER THE DESERT SW AND
ACCOMPANYING SFC LO PRES LIFT NE TOWARD THE UPR LKS. MUCH COOLER WX
WL DOMINATE UPR MI DURING MOST OF THE LONGER TERM.
SAT...SINCE THE UPR FLOW IS FCST TO REMAIN SW BTWN MEAN RDG OVER THE
SE CONUS AND GENERAL TROFFING IN CENTRAL NAMERICA...THE COLD FNT
ASSOCIATED WITH DEPARTING SFC LO IN QUEBEC IS PROGGED TO STALL OVER
THE LOWER GRT LKS. SOME RECENT MODEL RUNS HAVE SHOWN A LO PRES
RIDING ALONG THIS BNDRY AND BRINGING SOME PCPN TO MAINLY THE SE
CWA...BUT THE BULK OF THE LATEST RUNS NOW INDICATE THIS LO/PCPN WL
REMAIN TO THE SE OF UPR MI. DESPITE THE MORE AGGRESSIVE MID LVL
DRYING...LINGERING LLVL MSTR IN NE FLOW ON THE SE FLANK OF SFC HI
PRES OVER SCENTRAL CANADA WL LIKELY BRING SOME LO CLDS OVER THE
NCENTRAL AND E. PER THE 00Z NAM/CNDN FCST...DID MAINTAIN A MENTION
OF SOME SPRINKLES OVER THE NCENTRAL WHERE UPSLOPE WIND COMPONENT WL
BE MAXIMIZED. WITH LLVL NE FLOW OFF THE CHILLY LK WATERS...HI TEMPS
NEAR LK SUP IN THIS AREA WL BE HARD PRESSED TO GET OUT OF THE 40S.
WITH MORE SUNSHINE OVER THE W AND SCENTRAL...HI TEMPS SHOULD APRCH
60 WITH MIXING TO H85 ON FCST SDNGS.
SAT NGT...HI PRES IN SCENTRAL CANADA IS FCST TO DRIFT SLOWLY E INTO
FAR NW ONTARIO WHILE CLOSED LO LIFTING OUT OF THE DESERT SW CAUSES
SFC LO PRES IN THE CENTRAL PLAINS TO BEGIN SHIFTING NEWD. AS THE
LLVL FLOW OVER THE UPR LKS BEGINS TO VEER A BIT IN THE PRESENCE OF
NOCTURNAL COOLING...THE SC IMPACTING THE NCENTRAL AND E MAY TEND TO
DRIFT TOWARD THE W AND OVERSPREAD ALL BUT THE W WHERE THE LLVL ENE
FLOW DOWNSLOPES BY 12Z SUN. SOME HI CLDS WELL IN ADVANCE OF THE
CLOSED LO/SFC LO PRES MAY REACH THE WRN CWA BY DAYBREAK ON SUN.
SUN...ALTHOUGH CONTINUED VEERING LLVL FLOW TOWARD THE E WOULD ALLOW
FOR SOME LLVL MSTR/AT LEAST BKN LO CLDS TO IMPACT MUCH OF THE CWA...
SOME OF THE MODELS SHOW SOME LLVL DRYING ON THE SRN FLANK OF THE HI
IN FAR NW ONTARIO SUFFICIENT TO BREAK UP THIS CLD EXCEPT OVER THE
SCNTRAL. EVEN IF/WHERE THIS SC IS ABSENT...MID/HI CLDS WL BE INCRSG
IN DIFFLUENT UPR FLOW/INCRSG ISENTROPIC ASCENT IN ADVANCE OF CLOSED
LO MOVING NEWD THRU THE PLAINS. WITH ARRIVAL OF MORE VIGOROUS DEEP
LYR QVECTOR CNVGC/UPR DVGC IN THE AFTN...MOST OF THE MODELS DO
GENERATE SOME PCPN OVER AT LEAST THE WRN CWA IN THE AFTN...SO WL
MAINTAIN FCST HIER CHC POPS IN THAT AREA.
SUN NGT THRU TUE...AS NEGATIVELTY TILTED CLOSED LO OPENS UP AND
LIFTS ENEWD INTO THE UPR LKS BY TUE...SFC LO PRES IS PROGGED TO MOVE
ENEWD FM SE SDAKOTA ON SUN EVNG INTO WI BY LATE MON AND THEN INTO SE
ONTARIO BY TUE MRNG. THE TRACK OF THESE FEATURES AND ACCOMPANYING
DYNAMIC FORCING/DIFFLUENT UPR FLOW/DEEP CYC FLOW/PWAT AOA 1 INCH
INDICATE THERE WL BE AT LEAST PERIODS OF RA. IF THE UPR LO DRIFTS A
BIT FARTHER TO THE N...BREAKS IN THE PCPN WOULD BE MORE LIKELY
ESPECIALLY OVER THE SRN TIER. ON THE OTHER HAND...IF THE UPR LO
TRACKS A BIT FARTHER TO THE S...A MORE PERSISTENT CCB WOULD BRING
ABOUT MORE CONTINUOUS PCPN. THE LATEST CPC HAZARDS CHART INDICATES A
POTENTIAL FOR SOME HEAVY RA OVER THE ENTIRE CWA. DID INTRODUCE A
SCHC OF TS OVER THE FAR SCENTRAL SUN NGT INTO MON AS THE 00Z ECMWF
SHOWS A BIT FARTHER N TRACK OF THE UPR LO/HIER INSTABILITY OVER THAT
AREA. AS THE SFC LO EXITS TO THE E ON TUE...THE ARRIVAL OF COLDER
AIR WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W BEFORE THE EXIT
OF THE FORCING/ARRIVAL OF MORE ACYC FLOW CAUSES THE PCPN TO DIMINISH
LATER IN THE DAY. SINCE THE COLDER AIR WL ARRIVE AFTER 12Z
TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY
SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS.
WED/THU...CONSIDERABLE MODEL DIFFERENCES BECOME APRNT DURING THIS
LATER PORTION OF THE FCST. THE 00Z GFS IS MOST AGGRESSIVE WITH
MAINTAINING A LARGER SCALE TROF/COLDER AIR THRU WED...THEN SHOWS AN
UPR RDG/DRIER AIR DOMINATING THE AREA ON THU. THE 00Z ECMWF ON THE
OTHER HAND SHOWS BUILDING HGTS MUCH FASTER ON WED...AND THEN BRINGS
ANOTHER DISTURBANCE/SOME PCPN TOWARD THE AREA ON THU. WL RELY ON THE
MODEL CONSENSUS FCST THIS FAR OUT IN THE FCST PACKAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 138 PM EDT FRI MAY 8 2015
AT KIWD AND KCMX...A COLD FRONT MOVED THROUGH EARLIER...BRINGING
LOWERED CIGS. CONDITIONS WILL IMPROVE AS LOW LEVEL MOISTURE
DECREASES.
AT KSAW...THE COLD FRONT MOVED THROUGH SHORTLY BEFORE 18Z...BRINGING
NE WINDS OFF LAKE SUPERIOR AND SHOULD RESULT IN SOME DECREASED CIGS
THIS EVENING BEFORE SOME IMPROVEMENT EARLY TONIGHT. AN AREA OF LOW
LEVEL MOISTURE WILL MOVE INTO THE AREA WITH N-NNE WINDS LATE TONIGHT
AND SAT MORNING...RESULTING IN REDUCED CIGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT FRI MAY 8 2015
BEHIND A COLD FRONT MOVING THROUGH LAKE SUPERIOR TODAY...WINDS WILL
BECOME NW TO 20 KNOTS TONIGHT INTO SATURDAY. AREAS OF FOG WILL FORM
OVER LAKE SUPERIOR AS PRECIPITATION FALLS INTO THE ALREADY MOIST AIR
BELOW A STRONG INVERSION. AS LOW PRESSURE SLIDES FROM THE CENTRAL
PLAINS TO THE UPPER LAKES FROM SUNDAY INTO MONDAY...NORTH TO
NORTHEAST WINDS OF 20 TO 30 KNOTS ARE EXPECTED TO
DEVELOP...ESPECIALLY OVER THE WEST. SOME GALE FORCE GUSTS TO 35 KNOTS
WILL ALSO BE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...TITUS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
111 PM EDT FRI MAY 8 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 329 AM EDT FRI MAY 8 2015
WARM AND UNSETTLED WEATHER CAN BE EXPECTED ACROSS THE AREA FROM
TODAY RIGHT ON THROUGH THE WEEKEND AND INTO THE DAY ON MONDAY. WAVES
OF LOW PRESSURE WILL RIDE UP ALONG A FRONT THAT WILL BE MOVING BACK
AND FORTH ACROSS THE AREA. THESE WAVES WILL KEEP A THREAT OF SHOWERS
AND STORMS IN ACROSS THE AREA THROUGH MONDAY.
A STRONGER COLD FRONT WILL MOVE THROUGH LATER ON MONDAY. THIS FRONT
WILL BRING ANOTHER ROUND OF SHOWERS AND STORMS WILL IT. MUCH COOLER
AIR WILL EVENTUALLY MOVE IN ACROSS THE AREA.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 329 AM EDT FRI MAY 8 2015
OUR MAIN FOCUS IN THE SHORT TERM IS DETERMINING TIMING OF WAVES OF
BETTER CHCS OF SHOWERS AND STORMS...AND LOOKING AT ANY KIND OF
SEVERE WEATHER THREAT. WE ARE THINKING THAT A WIDESPREAD SEVERE
THREAT LOOKS QUITE LIMITED THROUGH THE UPCOMING WEEKEND...ALTHOUGH
THERE WILL BE MULTIPLE WAVES OF SHOWERS AND A FEW STORMS.
WE WILL SEE A LITTLE BETTER CHC FOR A FEW SHOWERS AND A STORM
TODAY...COMPARED TO YESTERDAY. THE MUCH BETTER CHC WILL COME
OVERNIGHT TONIGHT INTO SAT MORNING FOR THE AREA. THE MOISTURE AXIS
HAS SHIFTED OVER THE AREA...HOWEVER IT IS IN THE PROCESS OF
WEAKENING AS IT MOVES IN. THIS IS OCCURRING AS THE BETTER LLJ IS
STAYING WELL NORTH OF THE CWFA THIS MORNING AND MOVING AWAY.
WE WILL SEE ANOTHER LLJ OF 30+ KNOTS MOVE IN OVERNIGHT TONIGHT AHEAD
OF THE NEXT SHORT WAVE. THIS IS EXPECTED TO BRING RAIN TO MUCH OF
THE AREA. THIS WILL CONTINUE INTO SAT MORNING BEFORE IT MOVES NORTH
AND EAST OF THE AREA ON SAT AFTERNOON. THIS WILL ACTUALLY DROP THE
FRONT SOUTH THROUGH THE AREA AND PROVIDE FOR A SOMEWHAT DRIER PERIOD
FOR SAT NIGHT.
THE THREAT OF SHOWERS AND STORMS WILL THEN INCREASE ONCE AGAIN
DURING THE DAY ON SUN. WE WILL SEE A STRONG MID LEVEL FLOW TAKE
SHAPE OVER THE REGION AS THE UPPER LOW STARTS TO EJECT TO THE E/NE
FROM THE DESERT SW. THIS SCENARIO WILL HELP TO PUSH THE STALLED OUT
FRONT BACK NORTH AS A WARM FRONT. A NICE SLUG OF MOISTURE TRANSPORT
WILL MOVE UP INTO THE AREA...HELPING TO FOCUS SHOWERS AND STORMS
ALONG AND AHEAD OF THE WARM FRONT.
SEVERE WEATHER IS NOT LOOKING REAL LIKELY FOR THE AREA THROUGH THE
WEEKEND. INSTABILITY FOR TODAY AND TOMORROW IS GENERALLY A FEW
HUNDRED J/KG OF CAPE WITH LI/S OF AROUND -2 TO -4C. NO REAL THICK
CAPE PROFILES TO HELP WITH LARGE HAIL. WIND FIELDS ARE GENERALLY ON
THE LIGHTER SIDE...PRODUCING DEEP LAYER SHEAR VALUES OF UNDER 25-30
KNOTS. THE WARM FRONT COMING UP ON SUN IS A LITTLE CONCERNING. DEEP
LAYER SHEAR IS A BIT BETTER ALSO ON SUN AS THE MID LEVEL JET STREAK
MOVES CLOSER TO THE STATE.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 AM EDT FRI MAY 8 2015
IT WOULD SEEM STRONG STORMS ARE STILL POSSIBLE MONDAY AS THE PRIMARY
SYSTEM COMES OUT OF THE SOUTHWESTERN UNITED STATES AND PHASES WITH
THE NORTHERN STREAM WAVE. BEYOND THAT COOLER WEATHER WILL FOLLOW AT
LEAST INTO THE END OF NEXT WEEK.
THE MODELS REMAIN IN REASONABLE AGREEMENT ON THE TRACK OF THE
SURFACE LOW WILL TRACK WELL WEST OF SOUTHWEST LOWER MICHIGAN AS IT
COMES OUT OF THE SOUTHWESTERN UNITED STATES MONDAY. THE 00Z GFS
SEEMS MORE RELUCTANT TO BRING SOUTHWEST MICHIGAN INTO THE WARM
SECTOR OF THE STORM. IF THAT TURNS OUT TO BE TRUE THE SEVERE
STORMS WOULD STAY SOUTH OF THE AREA MONDAY. STILL ALL MODELS SHOW
SOUTHWEST MICHIGAN GETS INTO THE RIGHT REAR ENTRANCE REGION TO THE
UPPER JET AS IT LIFTS NORTHWARD THROUGH WISCONSIN MONDAY
AFTERNOON. WE STILL HAVE A 50 KNOT LOW LEVEL JET OVER EASTERN
LOWER MICHIGAN BY LATE AFTERNOON...THERE IS AT LEAST 1000 J/KG OF
MOST UNSTABLE CAPE AND THERE IS 50 KNOTS OF DEEP LAYER SHEAR. IT
REMAINS A QUESTION OF JUST HOW FAR NORTH THE WARM FRONT ACTUALLY
GETS MONDAY. IT REMAINS CLEAR SEVERE WEATHER IS STILL A REAL
THREAT FOR SOUTHWEST MICHIGAN MONDAY AFTERNOON.
BEYOND THAT ALL MODELS AGREE THE COLD AIR COMES IN FOR TUESDAY
THROUGH FRIDAY. NOW THOUGH THE ECMWF SHOWS A SYSTEM LIFTING OUT OF
THE SOUTHWESTERN UNITED STATES MOVING INTO OUR AREA BY THURSDAY.
THIS SEEMS TO FAST TO ME AND THE ECMWF WAS NOT DOING THIS PREVIOULSY
SO I DID NOT ACCOUNT FOR IT IN OUR ZONE FORECAST.
WE WILL HAVE TO WATCH WHAT HAPPENS TO TYPHOON NOUL. IT SEEMS TO WANT
TO RECUVE EARLY NEXT WEEK. LAST YEAR EVERY TIME THIS HAPPENED WE AND
WELL BELOW NORMAL TEMPERATURE FOR ABOUT A WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 715 AM EDT FRI MAY 8 2015
MOSTLY VFR CONDTIONS TODAY BUT SOME SCATTERED AFTERNOON
THUNDERSTORMS ARE POSSIBLE NEAR AND EAST OF US-131. THEY WILL BE
TOO SCATTERED TO PUT IN THE TAFS SO I HAVE VCTS UNTIL THE DETAILS
CAN BE ADDED ONCE THE STORMS DEVELOP.
A WAVE ON THE FRONT WILL BRING STEADY RAIN AFTER MIDNIGHT AND THIS
COULD BE A SOAKER. WHILE THUNDERSTORMS WILL BE POSSIBLE THE RISK
IT TO LOW TO EVEN UP VCTS AT THIS POINT. MOSTLY JUST RAIN...LOW
CLOUDS AND FOG BY MORNING.
&&
.MARINE...
ISSUED AT 746 AM EDT FRI MAY 8 2015
BASED ON HIGHER DEW POINTS MOVING OVER COLD LAKE MICHIGAN WATERS
AND THE HRRR SHOWING FOG BECOMING EXTENSIVE OVER LAKE MICHIGAN
TODAY I ADDED FOG TO THE NEAR SHORE WEATHER GRIDS. CURRENT WEB
CANS DO NOT SHOW MUCH FOG YET BUT I DO BELIEVE WE WILL SEE THE FOG
DEVELOP OVER TIME.
&&
.HYDROLOGY...
ISSUED AT 111 PM EDT FRI MAY 8 2015
RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR NORMAL
FLOWS FOR THIS TIME OF YEAR...ESPECIALLY CLOSER TO THE LAKESHORE.
SOME RIVERS FURTHER INLAND ACROSS PORTIONS OF CENTRAL AND MID-
MICHIGAN ARE RUNNING SLIGHTLY BELOW NORMAL...SUCH AS THE RED CEDAR
RIVER AT EAST LANSING...THE GRAND RIVER AT IONIA...AND THE MUSKEGON
RIVER AT EVART.
RIVER LEVEL RISES ARE EXPECTED THIS WEEKEND AND WILL CONTINUE INTO
NEXT WEEK. 1-2 INCHES OF RAINFALL IS POSSIBLE TODAY THROUGH MONDAY.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN
COVERAGE AND INTENSITY THIS EVENING. MORE WIDESPREAD RAINFALL IS
EXPECTED OVERNIGHT INTO SATURDAY MORNING. MINOR FLOODING IN URBAN
AND LOW-LYING AREAS WILL BE POSSIBLE TONIGHT INTO SATURDAY. WE HAVE
A FAIRLY MOIST ATMOSPHERE IN PLACE. UPPER AIR CLIMATOLOGY
INDICATES PRECIPITABLE WATER VALUES IN EXCESS OF THE 75TH
PERCENTILE. SFC DEWPOINTS ARE IN THE LOWER 60S THIS AFTERNOON WITH
MID TO UPPER 60S NOTED IN NW INDIANA AND NE ILLINOIS. ANY
CONVECTIVE RAIN SHOWERS OR STORMS THIS WEEKEND SHOULD BE FAIRLY
EFFICIENT RAINFALL PRODUCERS.
A DRY PERIOD IS FORECAST SATURDAY AFTERNOON THROUGH SATURDAY NIGHT
BEFORE RAIN AND STORM CHANCES INCREASE AGAIN ON SUNDAY. STRONG TO
SEVERE STORMS ARE POSSIBLE MONDAY...WHICH WILL HAVE TO POTENTIAL TO
PRODUCE HEAVY RAINFALL AND MINOR FLOODING. MORE SIGNIFICANT FLOODING
COULD OCCUR IF THE SAME AREAS SEE MODERATE TO HEAVY RAINFALL FROM
STORMS THIS EVENING AND TONIGHT AS WELL AS ON SUNDAY AND MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...EBW
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
746 AM EDT FRI MAY 8 2015
LATEST UPDATE...
MARINE
.SYNOPSIS...
ISSUED AT 329 AM EDT FRI MAY 8 2015
WARM AND UNSETTLED WEATHER CAN BE EXPECTED ACROSS THE AREA FROM
TODAY RIGHT ON THROUGH THE WEEKEND AND INTO THE DAY ON MONDAY. WAVES
OF LOW PRESSURE WILL RIDE UP ALONG A FRONT THAT WILL BE MOVING BACK
AND FORTH ACROSS THE AREA. THESE WAVES WILL KEEP A THREAT OF SHOWERS
AND STORMS IN ACROSS THE AREA THROUGH MONDAY.
A STRONGER COLD FRONT WILL MOVE THROUGH LATER ON MONDAY. THIS FRONT
WILL BRING ANOTHER ROUND OF SHOWERS AND STORMS WILL IT. MUCH COOLER
AIR WILL EVENTUALLY MOVE IN ACROSS THE AREA.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 329 AM EDT FRI MAY 8 2015
OUR MAIN FOCUS IN THE SHORT TERM IS DETERMINING TIMING OF WAVES OF
BETTER CHCS OF SHOWERS AND STORMS...AND LOOKING AT ANY KIND OF
SEVERE WEATHER THREAT. WE ARE THINKING THAT A WIDESPREAD SEVERE
THREAT LOOKS QUITE LIMITED THROUGH THE UPCOMING WEEKEND...ALTHOUGH
THERE WILL BE MULTIPLE WAVES OF SHOWERS AND A FEW STORMS.
WE WILL SEE A LITTLE BETTER CHC FOR A FEW SHOWERS AND A STORM
TODAY...COMPARED TO YESTERDAY. THE MUCH BETTER CHC WILL COME
OVERNIGHT TONIGHT INTO SAT MORNING FOR THE AREA. THE MOISTURE AXIS
HAS SHIFTED OVER THE AREA...HOWEVER IT IS IN THE PROCESS OF
WEAKENING AS IT MOVES IN. THIS IS OCCURRING AS THE BETTER LLJ IS
STAYING WELL NORTH OF THE CWFA THIS MORNING AND MOVING AWAY.
WE WILL SEE ANOTHER LLJ OF 30+ KNOTS MOVE IN OVERNIGHT TONIGHT AHEAD
OF THE NEXT SHORT WAVE. THIS IS EXPECTED TO BRING RAIN TO MUCH OF
THE AREA. THIS WILL CONTINUE INTO SAT MORNING BEFORE IT MOVES NORTH
AND EAST OF THE AREA ON SAT AFTERNOON. THIS WILL ACTUALLY DROP THE
FRONT SOUTH THROUGH THE AREA AND PROVIDE FOR A SOMEWHAT DRIER PERIOD
FOR SAT NIGHT.
THE THREAT OF SHOWERS AND STORMS WILL THEN INCREASE ONCE AGAIN
DURING THE DAY ON SUN. WE WILL SEE A STRONG MID LEVEL FLOW TAKE
SHAPE OVER THE REGION AS THE UPPER LOW STARTS TO EJECT TO THE E/NE
FROM THE DESERT SW. THIS SCENARIO WILL HELP TO PUSH THE STALLED OUT
FRONT BACK NORTH AS A WARM FRONT. A NICE SLUG OF MOISTURE TRANSPORT
WILL MOVE UP INTO THE AREA...HELPING TO FOCUS SHOWERS AND STORMS
ALONG AND AHEAD OF THE WARM FRONT.
SEVERE WEATHER IS NOT LOOKING REAL LIKELY FOR THE AREA THROUGH THE
WEEKEND. INSTABILITY FOR TODAY AND TOMORROW IS GENERALLY A FEW
HUNDRED J/KG OF CAPE WITH LI/S OF AROUND -2 TO -4C. NO REAL THICK
CAPE PROFILES TO HELP WITH LARGE HAIL. WIND FIELDS ARE GENERALLY ON
THE LIGHTER SIDE...PRODUCING DEEP LAYER SHEAR VALUES OF UNDER 25-30
KNOTS. THE WARM FRONT COMING UP ON SUN IS A LITTLE CONCERNING. DEEP
LAYER SHEAR IS A BIT BETTER ALSO ON SUN AS THE MID LEVEL JET STREAK
MOVES CLOSER TO THE STATE.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 AM EDT FRI MAY 8 2015
IT WOULD SEEM STRONG STORMS ARE STILL POSSIBLE MONDAY AS THE PRIMARY
SYSTEM COMES OUT OF THE SOUTHWESTERN UNITED STATES AND PHASES WITH
THE NORTHERN STREAM WAVE. BEYOND THAT COOLER WEATHER WILL FOLLOW AT
LEAST INTO THE END OF NEXT WEEK.
THE MODELS REMAIN IN REASONABLE AGREEMENT ON THE TRACK OF THE
SURFACE LOW WILL TRACK WELL WEST OF SOUTHWEST LOWER MICHIGAN AS IT
COMES OUT OF THE SOUTHWESTERN UNTIED STATES MONDAY. THE 00Z GFS
SEEMS MORE RELUCTANT TO BRING SOUTHWEST MICHIGAN INTO THE WARM
SECTOR OF THE STORM. IF THAT TURNS OUT TO BE TRUE THE SEVERE STORMS
WOULD STAY SOUTH OF THE AREA MONDAY. STILL ALL MODELS SHOW SOUTHWEST
MICHIGAN GETS INTO THE RIGHT REAR ENTRANCE REGION TO THE UPPER JET
AS IT LIFTS NORTHWARD THROUGH WISCONSIN MONDAY AFTERNOON. WE STILL
HAVE A 50 KNOT LOW LEVEL JET OVER EASTERN LOWER MICHIGAN BY LATE
AFTERNOON...THERE IS AT LEAST 1000 J/KG OF MOST UNSTABLE CAPE AND
THERE IS 50 KNOTS OF DEEP LAYER SHEAR. IT REMAINS A QUESTION OF
JUST HOW FAR NORTH THE WARM FRONT ACTUALLY GETS MONDAY. IT REMAINS
CLEAR SEVERE WEATHER IS STILL A REAL THREAT FOR SOUTHWEST MICHIGAN
MONDAY AFTERNOON.
BEYOND THAT ALL MODELS AGREE THE COLD AIR COMES IN FOR TUESDAY
THROUGH FRIDAY. NOW THOUGH THE ECMWF SHOWS A SYSTEM LIFTING OUT OF
THE SOUTHWESTERN UNITED STATES MOVING INTO OUR AREA BY THURSDAY.
THIS SEEMS TO FAST TO ME AND THE ECMWF WAS NOT DOING THIS PREVIOULSY
SO I DID NOT ACCOUNT FOR IT IN OUR ZONE FORECAST.
WE WILL HAVE TO WATCH WHAT HAPPENS TO TYPHOON NOUL. IT SEEMS TO WANT
TO RECUVE EARLY NEXT WEEK. LAST YEAR EVERY TIME THIS HAPPENED WE AND
WELL BELOW NORMAL TEMPERATURE FOR ABOUT A WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 715 AM EDT FRI MAY 8 2015
MOSTLY VFR CONDTIONS TODAY BUT SOME SCATTERED AFTERNOON
THUNDERSTORMS ARE POSSIBLE NEAR AND EAST OF US-131. THERE WILL BE
TO SCATTERED TO PUT IN THE TAFS SO I HAVE VCTS UNTIL THE DETAILS
CAN BE ADDED ONCE THE STORMS DEVELOP.
A WAVE ON THE FRONT WILL BRING STEADY RAIN AFTER MIDNIGHT AND THIS
COULD BE A SOAKER. WHILE THUNDERSTORMS WILL BE POSSIBLE THE RISK
IT TO LOW TO EVEN UP VCTS AT THIS POINT. MOSTLY JUST RAIN...LOW
CLOUDS AND FOG BY MORNING.
&&
.MARINE...
ISSUED AT 746 AM EDT FRI MAY 8 2015
BASED ON HIGHER DEW POINTS MOVING OVER COLD LAKE MICHIGAN WATERS
AND THE HRRR SHOWING FOG BECOMING EXTENSIVE OVER LAKE MICHIGAN
TODAY I ADDED FOG TO THE NEAR SHORE WEATHER GRIDS. CURRENT WEB
CANS DO NOT SHOW MUCH FOG YET BUT I DO BELIEVE WE WILL SEE THE FOG
DEVELOP OVER TIME.
&&
.HYDROLOGY...
ISSUED AT 124 PM EDT THU MAY 7 2015
NUMEROUS CHANCES FOR RAIN AND THUNDERSTORMS EXIST FRIDAY THROUGH
MONDAY NIGHT. 5-DAY QPF THROUGH MONDAY NIGHT IS IN THE 1.50 TO
2.00 INCH RANGE...WITH SOME UNCERTAINTY WITH THUNDERSTORMS.
MODERATE TO HEAVY RAINFALL WILL BE POSSIBLE AT TIMES FRIDAY
THROUGH MONDAY NIGHT.
THE CURRENT SYNOPTIC PATTERN IS CHARACTERIZED BY A DEEP UPPER
TROUGH OVER THE WEST COAST AND EASTERN CONUS RIDGE. LOWER MICHIGAN
IS ALREADY POSITIONED WITHIN A FAVORABLE MID AND UPPER LEVEL
SOUTHWEST FLOW REGIME. SFC DEWPOINTS ARE CURRENTLY PUSHING 60
DEGREES ACROSS SOUTHWEST LOWER MICHIGAN. A MOIST ATMOSPHERE WILL
PERSIST THROUGH THE WEEKEND AS MULTIPLE WAVES OF LOW PRESSURE
PROPAGATE NORTHEAST FROM THE PLAINS. THE FINAL MAIN COLD FRONT
PUSHES THROUGH MONDAY...WHEN STRONG TO SEVERE STORMS ARE POSSIBLE.
THERE IS A RISK FOR FLOODING THIS WEEKEND INTO EARLY NEXT
WEEK...ESPECIALLY BEGINNING MONDAY IF ANY STRONG TO SEVERE STORMS
PRODUCE HEAVY RAINFALL IN A RELATIVELY SHORT AMOUNT OF TIME. RIVER
LEVEL RISES ARE CERTAINLY EXPECTED INTO NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...EBW
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
726 AM EDT FRI MAY 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT FRI MAY 8 2015
WV IMAGERY AND RUC ANALYSIS INDICATED SW MID/UPPER LEVEL FLOW FROM
THE CNTRL/SRN PLAINS THROUGH THE WRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED THROUGH FAR WRN LAKE SUPERIOR INTO WRN WI FROM
LOW PRES OVER NW ONTARIO. THE COMBINATION OF LOW LEVEL CONV NEAR THE
FRONT AND A SHORTWAVE TROUGH FROM WRN LAKE SUPERIOR INTO NW WI
SUPPORTED SCT/ISOLD SHRA INTO FAR WRN UPPER MI. WITH NIGHTTIME
COOLING...THE CONVECTION HAD WEAKENED ENOUGH SO THAT NO LIGHTNING WAS
OBSERVED OVER THE REGION.
TODAY...THE FRONT WILL CONTINUE TO PUSH TO THE EAST AS THE LOW MOVES
TOWARD JAMES BAY. MODELS AND RADAR TRENDS SUGGEST THAT SCT/ISOLD
SHRA WILL CONTINUE TO SPREAD EASTWARD THROUGH WRN UPPER MI. EXPECT
HIGHER SHRA/TSRA CHANCES OVER THE CNTRL AND EAST...ESPECIALLY DURING
THE AFTERNOON WHEN THE FRONT MOVES INTO THE AREA DURING PEAK HEATING
WITH THE POTENTIAL TO INTERACT WITH LAKE BREEZE BOUNDARIES. WITH
MLCAPE VALUES OF ONLY 400-800 J/KG AND 0-6KM SHEAR OF 30-35
KNOTS...CONDITIONS WILL MARGINAL FOR ANY STRONGER STORMS. THERE IS
ALSO STILL UNCERTAINTY WITH THE AMOUNT CLOUD COVER AND
HEATING/INSTABILITY.
TONIGHT...AFTER THE SHRA/TSRA MOVE OUT OF THE ERN CWA DURING THE
EVENING...EXPECT DRY WEATHER OVERNIGHT. THE MODELS HAVE CONTINUED
TREND OF KEEPING SHRA/TSRA DEVELOPING ALONG THE FRONT TO THE SOUTH
AND EAST OF UPPER MI. SOME LIGHT SPRINKLES OR PATCHY DRIZZLE MAY
DEVELOP LATE NORTH CENTRAL WITH LINGERING LOW LEVEL MOISTURE AND A
PERIOD OF CYCLONIC NNE FLOW ASSOCIATED WITH A WEAK SFC TROUGH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 410 AM EDT FRI MAY 8 2015
MAIN FCST CONCERNS IN THE LONGER TERM FOCUS ON COVERAGE OF LO CLDS
ON SAT/SAT NGT AND THEN THE POTENTIAL FOR A WELCOME WDSPRD PCPN
EVENT EARLY NEXT WEEK AS THE CLOSED LO NOW OVER THE DESERT SW AND
ACCOMPANYING SFC LO PRES LIFT NE TOWARD THE UPR LKS. MUCH COOLER WX
WL DOMINATE UPR MI DURING MOST OF THE LONGER TERM.
SAT...SINCE THE UPR FLOW IS FCST TO REMAIN SW BTWN MEAN RDG OVER THE
SE CONUS AND GENERAL TROFFING IN CENTRAL NAMERICA...THE COLD FNT
ASSOCIATED WITH DEPARTING SFC LO IN QUEBEC IS PROGGED TO STALL OVER
THE LOWER GRT LKS. SOME RECENT MODEL RUNS HAVE SHOWN A LO PRES
RIDING ALONG THIS BNDRY AND BRINGING SOME PCPN TO MAINLY THE SE
CWA...BUT THE BULK OF THE LATEST RUNS NOW INDICATE THIS LO/PCPN WL
REMAIN TO THE SE OF UPR MI. DESPITE THE MORE AGGRESSIVE MID LVL
DRYING...LINGERING LLVL MSTR IN NE FLOW ON THE SE FLANK OF SFC HI
PRES OVER SCENTRAL CANADA WL LIKELY BRING SOME LO CLDS OVER THE
NCENTRAL AND E. PER THE 00Z NAM/CNDN FCST...DID MAINTAIN A MENTION
OF SOME SPRINKLES OVER THE NCENTRAL WHERE UPSLOPE WIND COMPONENT WL
BE MAXIMIZED. WITH LLVL NE FLOW OFF THE CHILLY LK WATERS...HI TEMPS
NEAR LK SUP IN THIS AREA WL BE HARD PRESSED TO GET OUT OF THE 40S.
WITH MORE SUNSHINE OVER THE W AND SCENTRAL...HI TEMPS SHOULD APRCH
60 WITH MIXING TO H85 ON FCST SDNGS.
SAT NGT...HI PRES IN SCENTRAL CANADA IS FCST TO DRIFT SLOWLY E INTO
FAR NW ONTARIO WHILE CLOSED LO LIFTING OUT OF THE DESERT SW CAUSES
SFC LO PRES IN THE CENTRAL PLAINS TO BEGIN SHIFTING NEWD. AS THE
LLVL FLOW OVER THE UPR LKS BEGINS TO VEER A BIT IN THE PRESENCE OF
NOCTURNAL COOLING...THE SC IMPACTING THE NCENTRAL AND E MAY TEND TO
DRIFT TOWARD THE W AND OVERSPREAD ALL BUT THE W WHERE THE LLVL ENE
FLOW DOWNSLOPES BY 12Z SUN. SOME HI CLDS WELL IN ADVANCE OF THE
CLOSED LO/SFC LO PRES MAY REACH THE WRN CWA BY DAYBREAK ON SUN.
SUN...ALTHOUGH CONTINUED VEERING LLVL FLOW TOWARD THE E WOULD ALLOW
FOR SOME LLVL MSTR/AT LEAST BKN LO CLDS TO IMPACT MUCH OF THE CWA...
SOME OF THE MODELS SHOW SOME LLVL DRYING ON THE SRN FLANK OF THE HI
IN FAR NW ONTARIO SUFFICIENT TO BREAK UP THIS CLD EXCEPT OVER THE
SCNTRAL. EVEN IF/WHERE THIS SC IS ABSENT...MID/HI CLDS WL BE INCRSG
IN DIFFLUENT UPR FLOW/INCRSG ISENTROPIC ASCENT IN ADVANCE OF CLOSED
LO MOVING NEWD THRU THE PLAINS. WITH ARRIVAL OF MORE VIGOROUS DEEP
LYR QVECTOR CNVGC/UPR DVGC IN THE AFTN...MOST OF THE MODELS DO
GENERATE SOME PCPN OVER AT LEAST THE WRN CWA IN THE AFTN...SO WL
MAINTAIN FCST HIER CHC POPS IN THAT AREA.
SUN NGT THRU TUE...AS NEGATIVELTY TILTED CLOSED LO OPENS UP AND
LIFTS ENEWD INTO THE UPR LKS BY TUE...SFC LO PRES IS PROGGED TO MOVE
ENEWD FM SE SDAKOTA ON SUN EVNG INTO WI BY LATE MON AND THEN INTO SE
ONTARIO BY TUE MRNG. THE TRACK OF THESE FEATURES AND ACCOMPANYING
DYNAMIC FORCING/DIFFLUENT UPR FLOW/DEEP CYC FLOW/PWAT AOA 1 INCH
INDICATE THERE WL BE AT LEAST PERIODS OF RA. IF THE UPR LO DRIFTS A
BIT FARTHER TO THE N...BREAKS IN THE PCPN WOULD BE MORE LIKELY
ESPECIALLY OVER THE SRN TIER. ON THE OTHER HAND...IF THE UPR LO
TRACKS A BIT FARTHER TO THE S...A MORE PERSISTENT CCB WOULD BRING
ABOUT MORE CONTINUOUS PCPN. THE LATEST CPC HAZARDS CHART INDICATES A
POTENTIAL FOR SOME HEAVY RA OVER THE ENTIRE CWA. DID INTRODUCE A
SCHC OF TS OVER THE FAR SCENTRAL SUN NGT INTO MON AS THE 00Z ECMWF
SHOWS A BIT FARTHER N TRACK OF THE UPR LO/HIER INSTABILITY OVER THAT
AREA. AS THE SFC LO EXITS TO THE E ON TUE...THE ARRIVAL OF COLDER
AIR WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W BEFORE THE EXIT
OF THE FORCING/ARRIVAL OF MORE ACYC FLOW CAUSES THE PCPN TO DIMINISH
LATER IN THE DAY. SINCE THE COLDER AIR WL ARRIVE AFTER 12Z
TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY
SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS.
WED/THU...CONSIDERABLE MODEL DIFFERENCES BECOME APRNT DURING THIS
LATER PORTION OF THE FCST. THE 00Z GFS IS MOST AGGRESSIVE WITH
MAINTAINING A LARGER SCALE TROF/COLDER AIR THRU WED...THEN SHOWS AN
UPR RDG/DRIER AIR DOMINATING THE AREA ON THU. THE 00Z ECMWF ON THE
OTHER HAND SHOWS BUILDING HGTS MUCH FASTER ON WED...AND THEN BRINGS
ANOTHER DISTURBANCE/SOME PCPN TOWARD THE AREA ON THU. WL RELY ON THE
MODEL CONSENSUS FCST THIS FAR OUT IN THE FCST PACKAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 725 AM EDT FRI MAY 8 2015
EXPECT AN EXTENSVIE AREA OF IFR CIGS BEHIND A COLD FRONT...INCLUDING
IWD/CMX TO GRADUALLY IMPROVE THIS MORNING AS DRIER AIR MOVES INTO
THE REGION. VFR CONDITIONS ARE THEN EXPECTED BY LATE THIS EVENING.
AT SAW...LAKE BREEZE AND COLD FRONT MAY TRIGGE SOME MVFR CIGS AND
SHOWERS THIS AFTERNOON WITH VFR CONDITIONS RETURNING THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT FRI MAY 8 2015
BEHIND A COLD FRONT MOVING THROUGH LAKE SUPERIOR TODAY...WINDS WILL
BECOME NW TO 20 KNOTS TONIGHT INTO SATURDAY. AREAS OF FOG WILL FORM
OVER LAKE SUPERIOR AS PRECIPITATION FALLS INTO THE ALREADY MOIST AIR
BELOW A STRONG INVERSION. AS LOW PRESSURE SLIDES FROM THE CENTRAL
PLAINS TO THE UPPER LAKES FROM SUNDAY INTO MONDAY...NORTH TO
NORTHEAST WINDS OF 20 TO 30 KNOTS ARE EXPECTED TO
DEVELOP...ESPECIALLY OVER THE WEST. SOME GALE FORCE GUSTS TO 35 KNOTS
WILL ALSO BE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
445 AM EDT FRI MAY 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT FRI MAY 8 2015
WV IMAGERY AND RUC ANALYSIS INDICATED SW MID/UPPER LEVEL FLOW FROM
THE CNTRL/SRN PLAINS THROUGH THE WRN GREAT LAKES. AT THE SFC...A
COLD FRONT EXTENDED THROUGH FAR WRN LAKE SUPERIOR INTO WRN WI FROM
LOW PRES OVER NW ONTARIO. THE COMBINATION OF LOW LEVEL CONV NEAR THE
FRONT AND A SHORTWAVE TROUGH FROM WRN LAKE SUPERIOR INTO NW WI
SUPPORTED SCT/ISOLD SHRA INTO FAR WRN UPPER MI. WITH NIGHTTIME
COOLING...THE CONVECTION HAD WEAKENED ENOUGH SO THAT NO LIGHTNING WAS
OBSERVED OVER THE REGION.
TODAY...THE FRONT WILL CONTINUE TO PUSH TO THE EAST AS THE LOW MOVES
TOWARD JAMES BAY. MODELS AND RADAR TRENDS SUGGEST THAT SCT/ISOLD
SHRA WILL CONTINUE TO SPREAD EASTWARD THROUGH WRN UPPER MI. EXPECT
HIGHER SHRA/TSRA CHANCES OVER THE CNTRL AND EAST...ESPECIALLY DURING
THE AFTERNOON WHEN THE FRONT MOVES INTO THE AREA DURING PEAK HEATING
WITH THE POTENTIAL TO INTERACT WITH LAKE BREEZE BOUNDARIES. WITH
MLCAPE VALUES OF ONLY 400-800 J/KG AND 0-6KM SHEAR OF 30-35
KNOTS...CONDITIONS WILL MARGINAL FOR ANY STRONGER STORMS. THERE IS
ALSO STILL UNCERTAINTY WITH THE AMOUNT CLOUD COVER AND
HEATING/INSTABILITY.
TONIGHT...AFTER THE SHRA/TSRA MOVE OUT OF THE ERN CWA DURING THE
EVENING...EXPECT DRY WEATHER OVERNIGHT. THE MODELS HAVE CONTINUED
TREND OF KEEPING SHRA/TSRA DEVELOPING ALONG THE FRONT TO THE SOUTH
AND EAST OF UPPER MI. SOME LIGHT SPRINKLES OR PATCHY DRIZZLE MAY
DEVELOP LATE NORTH CENTRAL WITH LINGERING LOW LEVEL MOISTURE AND A
PERIOD OF CYCLONIC NNE FLOW ASSOCIATED WITH A WEAK SFC TROUGH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 410 AM EDT FRI MAY 8 2015
MAIN FCST CONCERNS IN THE LONGER TERM FOCUS ON COVERAGE OF LO CLDS
ON SAT/SAT NGT AND THEN THE POTENTIAL FOR A WELCOME WDSPRD PCPN
EVENT EARLY NEXT WEEK AS THE CLOSED LO NOW OVER THE DESERT SW AND
ACCOMPANYING SFC LO PRES LIFT NE TOWARD THE UPR LKS. MUCH COOLER WX
WL DOMINATE UPR MI DURING MOST OF THE LONGER TERM.
SAT...SINCE THE UPR FLOW IS FCST TO REMAIN SW BTWN MEAN RDG OVER THE
SE CONUS AND GENERAL TROFFING IN CENTRAL NAMERICA...THE COLD FNT
ASSOCIATED WITH DEPARTING SFC LO IN QUEBEC IS PROGGED TO STALL OVER
THE LOWER GRT LKS. SOME RECENT MODEL RUNS HAVE SHOWN A LO PRES
RIDING ALONG THIS BNDRY AND BRINGING SOME PCPN TO MAINLY THE SE
CWA...BUT THE BULK OF THE LATEST RUNS NOW INDICATE THIS LO/PCPN WL
REMAIN TO THE SE OF UPR MI. DESPITE THE MORE AGGRESSIVE MID LVL
DRYING...LINGERING LLVL MSTR IN NE FLOW ON THE SE FLANK OF SFC HI
PRES OVER SCENTRAL CANADA WL LIKELY BRING SOME LO CLDS OVER THE
NCENTRAL AND E. PER THE 00Z NAM/CNDN FCST...DID MAINTAIN A MENTION
OF SOME SPRINKLES OVER THE NCENTRAL WHERE UPSLOPE WIND COMPONENT WL
BE MAXIMIZED. WITH LLVL NE FLOW OFF THE CHILLY LK WATERS...HI TEMPS
NEAR LK SUP IN THIS AREA WL BE HARD PRESSED TO GET OUT OF THE 40S.
WITH MORE SUNSHINE OVER THE W AND SCENTRAL...HI TEMPS SHOULD APRCH
60 WITH MIXING TO H85 ON FCST SDNGS.
SAT NGT...HI PRES IN SCENTRAL CANADA IS FCST TO DRIFT SLOWLY E INTO
FAR NW ONTARIO WHILE CLOSED LO LIFTING OUT OF THE DESERT SW CAUSES
SFC LO PRES IN THE CENTRAL PLAINS TO BEGIN SHIFTING NEWD. AS THE
LLVL FLOW OVER THE UPR LKS BEGINS TO VEER A BIT IN THE PRESENCE OF
NOCTURNAL COOLING...THE SC IMPACTING THE NCENTRAL AND E MAY TEND TO
DRIFT TOWARD THE W AND OVERSPREAD ALL BUT THE W WHERE THE LLVL ENE
FLOW DOWNSLOPES BY 12Z SUN. SOME HI CLDS WELL IN ADVANCE OF THE
CLOSED LO/SFC LO PRES MAY REACH THE WRN CWA BY DAYBREAK ON SUN.
SUN...ALTHOUGH CONTINUED VEERING LLVL FLOW TOWARD THE E WOULD ALLOW
FOR SOME LLVL MSTR/AT LEAST BKN LO CLDS TO IMPACT MUCH OF THE CWA...
SOME OF THE MODELS SHOW SOME LLVL DRYING ON THE SRN FLANK OF THE HI
IN FAR NW ONTARIO SUFFICIENT TO BREAK UP THIS CLD EXCEPT OVER THE
SCNTRAL. EVEN IF/WHERE THIS SC IS ABSENT...MID/HI CLDS WL BE INCRSG
IN DIFFLUENT UPR FLOW/INCRSG ISENTROPIC ASCENT IN ADVANCE OF CLOSED
LO MOVING NEWD THRU THE PLAINS. WITH ARRIVAL OF MORE VIGOROUS DEEP
LYR QVECTOR CNVGC/UPR DVGC IN THE AFTN...MOST OF THE MODELS DO
GENERATE SOME PCPN OVER AT LEAST THE WRN CWA IN THE AFTN...SO WL
MAINTAIN FCST HIER CHC POPS IN THAT AREA.
SUN NGT THRU TUE...AS NEGATIVELTY TILTED CLOSED LO OPENS UP AND
LIFTS ENEWD INTO THE UPR LKS BY TUE...SFC LO PRES IS PROGGED TO MOVE
ENEWD FM SE SDAKOTA ON SUN EVNG INTO WI BY LATE MON AND THEN INTO SE
ONTARIO BY TUE MRNG. THE TRACK OF THESE FEATURES AND ACCOMPANYING
DYNAMIC FORCING/DIFFLUENT UPR FLOW/DEEP CYC FLOW/PWAT AOA 1 INCH
INDICATE THERE WL BE AT LEAST PERIODS OF RA. IF THE UPR LO DRIFTS A
BIT FARTHER TO THE N...BREAKS IN THE PCPN WOULD BE MORE LIKELY
ESPECIALLY OVER THE SRN TIER. ON THE OTHER HAND...IF THE UPR LO
TRACKS A BIT FARTHER TO THE S...A MORE PERSISTENT CCB WOULD BRING
ABOUT MORE CONTINUOUS PCPN. THE LATEST CPC HAZARDS CHART INDICATES A
POTENTIAL FOR SOME HEAVY RA OVER THE ENTIRE CWA. DID INTRODUCE A
SCHC OF TS OVER THE FAR SCENTRAL SUN NGT INTO MON AS THE 00Z ECMWF
SHOWS A BIT FARTHER N TRACK OF THE UPR LO/HIER INSTABILITY OVER THAT
AREA. AS THE SFC LO EXITS TO THE E ON TUE...THE ARRIVAL OF COLDER
AIR WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W BEFORE THE EXIT
OF THE FORCING/ARRIVAL OF MORE ACYC FLOW CAUSES THE PCPN TO DIMINISH
LATER IN THE DAY. SINCE THE COLDER AIR WL ARRIVE AFTER 12Z
TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY
SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS.
WED/THU...CONSIDERABLE MODEL DIFFERENCES BECOME APRNT DURING THIS
LATER PORTION OF THE FCST. THE 00Z GFS IS MOST AGGRESSIVE WITH
MAINTAINING A LARGER SCALE TROF/COLDER AIR THRU WED...THEN SHOWS AN
UPR RDG/DRIER AIR DOMINATING THE AREA ON THU. THE 00Z ECMWF ON THE
OTHER HAND SHOWS BUILDING HGTS MUCH FASTER ON WED...AND THEN BRINGS
ANOTHER DISTURBANCE/SOME PCPN TOWARD THE AREA ON THU. WL RELY ON THE
MODEL CONSENSUS FCST THIS FAR OUT IN THE FCST PACKAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 125 AM EDT FRI MAY 8 2015
WILL SEE CONTINUED ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
WITH IFR/MVFR CEILINGS MOVING IN AHEAD OF THE APPROACHING COLD FRONT
LATE TONIGHT AT IWD AND CMX. SOME IMPROVEMENT EXPECTED FRIDAY
AFTERNOON AND EVENING. AT SAW...LAKE BREEZE AND COLD FRONT KICK OFF
SOME MVFR CIGS AND SHOWERS FRI AFTERNOON AND THEN VFR CONDITIONS
RETURN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT FRI MAY 8 2015
BEHIND A COLD FRONT MOVING THROUGH LAKE SUPERIOR TODAY...WINDS WILL
BECOME NW TO 20 KNOTS TONIGHT INTO SATURDAY. AREAS OF FOG WILL FORM
OVER LAKE SUPERIOR AS PRECIPITATION FALLS INTO THE ALREADY MOIST AIR
BELOW A STRONG INVERSION. AS LOW PRESSURE SLIDES FROM THE CENTRAL
PLAINS TO THE UPPER LAKES FROM SUNDAY INTO MONDAY...NORTH TO
NORTHEAST WINDS OF 20 TO 30 KNOTS ARE EXPECTED TO
DEVELOP...ESPECIALLY OVER THE WEST. SOME GALE FORCE GUSTS TO 35 KNOTS
WILL ALSO BE POSSIBLE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
1010 PM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 1010 PM CDT SAT MAY 9 2015
LOWERED MIN TEMPS ALONG THE NORTH SHORE A FEW DEGREES AS COLDER
AIR FROM LAKE SUPERIOR IS AFFECTING THE AREA. REST OF THE FORECAST
ON TRACK.
UPDATE ISSUED AT 717 PM CDT SAT MAY 9 2015
MADE SOME ADJUSTMENTS TO CLOUD COVER WITH LARGE AREA OF CLEAR SKY
IN NW WI AT 00Z. DELAYED THE ONSET OF THE PCPN UNTIL AFTER 12Z
SUNDAY PER THE LATEST SHORT TERM HRRR AND RAP. REST OF THE
FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
HIGH PRESSURE OVER SOUTHERN CANADA WILL CONTINUE TO GIVE THE
NORTHLAND DRY NORTH TO NE FLOW THROUGH TONIGHT. A STUBBORN LOW
LEVEL CLOUD DECK OVER NE MINNESOTA WILL SLOWLY SCATTER OUT THROUGH
THE REST OF THE THIS AFTERNOON AND EARLY THIS EVENING. THE CLOUD
DECK HAS BEEN SLOW TO ERODE BECAUSE OF THE LACK OF WIND TO MIX IT
OUT...BUT NW WISCONSIN HAS CLEARED OUT DUE TO STRONGER WINDS
COMING OFF OF LAKE SUPERIOR.
A LOW PRESSURE SYSTEM IN EASTERN COLORADO WILL MOVE INTO THE
CENTRAL PLAINS TONIGHT AND SUNDAY ON TRACK TOWARDS MINNESOTA. THIS
SYSTEM WILL BRING INCREASING MID LEVEL MOISTURE INTO THE UPPER
MIDWEST AND EVENTUALLY RAINS. IT WILL TAKE SOME TIME FOR THE LOW
LEVELS DUE TO THE THE RELATIVELY DRY FLOW FROM CANADA...SO THIS
MEANS IT WILL TAKE SOME TIME FOR THE RAINS TO MOVE INTO THE
REGION. THE GFS/NAM/SREF/GEM/ECMWF MODELS DRASTICALLY DELAYED THE
TIMING WITH WHICH THE PCPN MOVES INTO THE NORTHLAND...SO REFLECTED
THIS IN THE LATEST FORECAST.
SUNDAY IS MAINLY EXPECTED TO BE A COOL AND WINDY DAY. THERE WILL
BE INCREASING ENE WINDS WITH THE STRONGEST WINDS DOWNWIND OF LAKE
SUPERIOR...WHERE GUSTS OF 25 TO 35 MPH ARE POSSIBLE. TEMPERATURES
WILL ONLY REACH THE LOWER 40S NEAR LAKE SUPERIOR...BUT MORE INLAND
AREAS SHOULD REACH THE 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
FOCUS IN EXTENDED ON THE COOL TEMPERATURES AND SNOW CHANCES AS A
CUT OFF LOW TRACKS OUT OF THE DAKOTAS SUNDAY NIGHT...AND MIGRATES
SLOWLY ACROSS MINNESOTA/WESTERN LAKE SUPERIOR MONDAY/MONDAY
NIGHT.
THE LOW WILL BRING A PROLONGED PERIODS OF RAIN...AND ISOLATED
THUNDER. HAVE CONTINUED TO CARRY HIGH/DEFINITE POPS SUNDAY NIGHT
THROUGH MONDAY NIGHT. AT THIS TIME...THE HEAVIEST RAINFALL IS
EXPECTED ACROSS THE IRON RANGE/ARROWHEAD REGION OF NORTHEAST
MN...WITH TOTALS THROUGH TUESDAY OF AROUND INCH.
MODELS ARE IN GOOD AGREEMENT THAT BELOW ZERO H85 TEMPS WRAP
AROUND THE BACK SIDE OF THE LOW MONDAY...SPREADING OVER THE
NORTHLAND MONDAY NIGHT AND TUESDAY. THIS WILL BRING A CHANCE OF
SNOW OR A RAIN/SNOW MIX FOR THE MONDAY NIGHT AND TUESDAY PERIODS.
LATEST NAM/GFS BUFR SOUNDINGS AT KELO AND KHIB SHOW DEEPLY
SATURATED LOW AND MID LEVELS...PWATS AROUND 3/4 OF AN INCH...AND
TEMP PROFILES JUST ABOVE THE SFC REMAINING WELL BELOW THE ZERO
ISOTHERM. ALTHOUGH A PERIOD OF SNOW IS EXPECTED...AND SOME
ACCUMULATION WILL BE POSSIBLE IN THE MN ARROWHEAD/SOUTH SHORE
REGION...MOST LOCATIONS CAN EXPECT THE SNOW TO MELT AS IT REACHES
THE GROUND WITH ONLY ACCUMULATION ON ELEVATED SURFACES.
HAVE INCREASED POPS TUESDAY ABOVE THE SUPERBLEND GUIDANCE AS
STEEP LAPSE RATES...AROUND 100 J/KG OF CAPE...AND WRAP AROUND
MOISTURE WILL SUPPORT A TYPICAL POST-LOW DAY OF INSTABILITY
SHOWERS. THE SHOWERS WILL LIKELY MIX WITH SNOW DURING THE MORNING
HOURS...CHANGING TO ALL RAIN IN THE AFTERNOON...WITH LIGHT QPF ON
THE ORDER OF A FEW HUNDREDTHS. THE EXCEPTION IS ALONG THE GOGEBIC
RANGE IN NRN WISCONSIN WHERE TEMPERATURES WILL BE COOLER AND THE
RAIN/SNOW MIX MAY PERSIST THROUGH THE EVENING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 710 PM CDT SAT MAY 9 2015
AN AREA OF LOW PRESSURE WILL TRACK ACROSS NEBRASKA INTO SOUTHWEST
MINNESOTA BY EARLY MONDAY MORNING...WHILE HIGH PRESSURE BUILDS
OVER WESTERN HUDSON BAY. THE INTERACTION BETWEEN THE HIGH AND LOW
WILL CREATE A TIGHT PRESSURE GRADIENT OVER AREA. AS A RESULT GUSTY
EASTERLY AND NORTHEASTERLY WINDS AROUND 25 KT WILL DEVELOP AROUND
MID SUNDAY MORNING. GUSTY WINDS WILL PERSIST THROUGH MONDAY WITH THE
HIGHEST GUSTS APPROACHING 40 KT AT KDLH.
LIGHT RAIN WILL GRADUALLY SPREAD INTO THE FORECAST AREA ON SUNDAY
AS THE WARM FRONT ASSOCIATED WITH THE LOW MOVES IN. ALL SITES
EXCEPT FOR KBRD ARE EXPECTED TO REMAIN AT VFR CONDITIONS THROUGH
THE FORECAST PERIOD. LATEST GUIDANCE BRINGS MVFR CIGS AND VIS
AROUND 20Z FOR KBRD...WITH IFR CIGS POSSIBLE DURING THIS TIME
FRAME. KDLH...KHIB AND KHYR TERMINALS MAY SEE MVFR CIGS DEVELOP
LATE IN THE TAF PERIOD...BUT DID NOT FEEL CONFIDENT DUE TO THE
DRIER AIR IN THE LOWER LEVELS ALONG WITH A SLOWER ONSET OF
PRECIPITATION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 37 47 38 41 / 0 20 100 80
INL 37 54 37 40 / 0 30 80 90
BRD 41 52 39 49 / 0 80 90 70
HYR 39 58 45 54 / 0 40 90 60
ASX 35 47 40 41 / 0 20 80 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...GALE WARNING FROM 10 AM SUNDAY TO 7 PM CDT MONDAY FOR LSZ121-
140>148.
&&
$$
UPDATE...GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...GRANING
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
717 PM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 717 PM CDT SAT MAY 9 2015
MADE SOME ADJUSTMENTS TO CLOUD COVER WITH LARGE AREA OF CLEAR SKY
IN NW WI AT 00Z. DELAYED THE ONSET OF THE PCPN UNTIL AFTER 12Z
SUNDAY PER THE LATEST SHORT TERM HRRR AND RAP. REST OF THE
FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
HIGH PRESSURE OVER SOUTHERN CANADA WILL CONTINUE TO GIVE THE
NORTHLAND DRY NORTH TO NE FLOW THROUGH TONIGHT. A STUBBORN LOW
LEVEL CLOUD DECK OVER NE MINNESOTA WILL SLOWLY SCATTER OUT THROUGH
THE REST OF THE THIS AFTERNOON AND EARLY THIS EVENING. THE CLOUD
DECK HAS BEEN SLOW TO ERODE BECAUSE OF THE LACK OF WIND TO MIX IT
OUT...BUT NW WISCONSIN HAS CLEARED OUT DUE TO STRONGER WINDS
COMING OFF OF LAKE SUPERIOR.
A LOW PRESSURE SYSTEM IN EASTERN COLORADO WILL MOVE INTO THE
CENTRAL PLAINS TONIGHT AND SUNDAY ON TRACK TOWARDS MINNESOTA. THIS
SYSTEM WILL BRING INCREASING MID LEVEL MOISTURE INTO THE UPPER
MIDWEST AND EVENTUALLY RAINS. IT WILL TAKE SOME TIME FOR THE LOW
LEVELS DUE TO THE THE RELATIVELY DRY FLOW FROM CANADA...SO THIS
MEANS IT WILL TAKE SOME TIME FOR THE RAINS TO MOVE INTO THE
REGION. THE GFS/NAM/SREF/GEM/ECMWF MODELS DRASTICALLY DELAYED THE
TIMING WITH WHICH THE PCPN MOVES INTO THE NORTHLAND...SO REFLECTED
THIS IN THE LATEST FORECAST.
SUNDAY IS MAINLY EXPECTED TO BE A COOL AND WINDY DAY. THERE WILL
BE INCREASING ENE WINDS WITH THE STRONGEST WINDS DOWNWIND OF LAKE
SUPERIOR...WHERE GUSTS OF 25 TO 35 MPH ARE POSSIBLE. TEMPERATURES
WILL ONLY REACH THE LOWER 40S NEAR LAKE SUPERIOR...BUT MORE INLAND
AREAS SHOULD REACH THE 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
FOCUS IN EXTENDED ON THE COOL TEMPERATURES AND SNOW CHANCES AS A
CUT OFF LOW TRACKS OUT OF THE DAKOTAS SUNDAY NIGHT...AND MIGRATES
SLOWLY ACROSS MINNESOTA/WESTERN LAKE SUPERIOR MONDAY/MONDAY
NIGHT.
THE LOW WILL BRING A PROLONGED PERIODS OF RAIN...AND ISOLATED
THUNDER. HAVE CONTINUED TO CARRY HIGH/DEFINITE POPS SUNDAY NIGHT
THROUGH MONDAY NIGHT. AT THIS TIME...THE HEAVIEST RAINFALL IS
EXPECTED ACROSS THE IRON RANGE/ARROWHEAD REGION OF NORTHEAST
MN...WITH TOTALS THROUGH TUESDAY OF AROUND INCH.
MODELS ARE IN GOOD AGREEMENT THAT BELOW ZERO H85 TEMPS WRAP
AROUND THE BACK SIDE OF THE LOW MONDAY...SPREADING OVER THE
NORTHLAND MONDAY NIGHT AND TUESDAY. THIS WILL BRING A CHANCE OF
SNOW OR A RAIN/SNOW MIX FOR THE MONDAY NIGHT AND TUESDAY PERIODS.
LATEST NAM/GFS BUFR SOUNDINGS AT KELO AND KHIB SHOW DEEPLY
SATURATED LOW AND MID LEVELS...PWATS AROUND 3/4 OF AN INCH...AND
TEMP PROFILES JUST ABOVE THE SFC REMAINING WELL BELOW THE ZERO
ISOTHERM. ALTHOUGH A PERIOD OF SNOW IS EXPECTED...AND SOME
ACCUMULATION WILL BE POSSIBLE IN THE MN ARROWHEAD/SOUTH SHORE
REGION...MOST LOCATIONS CAN EXPECT THE SNOW TO MELT AS IT REACHES
THE GROUND WITH ONLY ACCUMULATION ON ELEVATED SURFACES.
HAVE INCREASED POPS TUESDAY ABOVE THE SUPERBLEND GUIDANCE AS
STEEP LAPSE RATES...AROUND 100 J/KG OF CAPE...AND WRAP AROUND
MOISTURE WILL SUPPORT A TYPICAL POST-LOW DAY OF INSTABILITY
SHOWERS. THE SHOWERS WILL LIKELY MIX WITH SNOW DURING THE MORNING
HOURS...CHANGING TO ALL RAIN IN THE AFTERNOON...WITH LIGHT QPF ON
THE ORDER OF A FEW HUNDREDTHS. THE EXCEPTION IS ALONG THE GOGEBIC
RANGE IN NRN WISCONSIN WHERE TEMPERATURES WILL BE COOLER AND THE
RAIN/SNOW MIX MAY PERSIST THROUGH THE EVENING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 710 PM CDT SAT MAY 9 2015
AN AREA OF LOW PRESSURE WILL TRACK ACROSS NEBRASKA INTO SOUTHWEST
MINNESOTA BY EARLY MONDAY MORNING...WHILE HIGH PRESSURE BUILDS
OVER WESTERN HUDSON BAY. THE INTERACTION BETWEEN THE HIGH AND LOW
WILL CREATE A TIGHT PRESSURE GRADIENT OVER AREA. AS A RESULT GUSTY
EASTERLY AND NORTHEASTERLY WINDS AROUND 25 KT WILL DEVELOP AROUND
MID SUNDAY MORNING. GUSTY WINDS WILL PERSIST THROUGH MONDAY WITH THE
HIGHEST GUSTS APPROACHING 40 KT AT KDLH.
LIGHT RAIN WILL GRADUALLY SPREAD INTO THE FORECAST AREA ON SUNDAY
AS THE WARM FRONT ASSOCIATED WITH THE LOW MOVES IN. ALL SITES
EXCEPT FOR KBRD ARE EXPECTED TO REMAIN AT VFR CONDITIONS THROUGH
THE FORECAST PERIOD. LATEST GUIDANCE BRINGS MVFR CIGS AND VIS
AROUND 20Z FOR KBRD...WITH IFR CIGS POSSIBLE DURING THIS TIME
FRAME. KDLH...KHIB AND KHYR TERMINALS MAY SEE MVFR CIGS DEVELOP
LATE IN THE TAF PERIOD...BUT DID NOT FEEL CONFIDENT DUE TO THE
DRIER AIR IN THE LOWER LEVELS ALONG WITH A SLOWER ONSET OF
PRECIPITATION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 37 47 38 41 / 0 20 100 80
INL 37 54 37 40 / 0 30 80 90
BRD 41 52 39 49 / 0 80 90 70
HYR 39 58 45 54 / 0 40 90 60
ASX 35 47 40 41 / 0 20 80 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...GALE WARNING FROM 10 AM SUNDAY TO 7 PM CDT MONDAY FOR LSZ121-
140>148.
&&
$$
UPDATE...GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...GRANING
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
321 PM CDT FRI MAY 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 321 PM CDT FRI MAY 8 2015
CLEARING HAS BEEN SLOW THIS AFTERNOON...BUT HAS BEEN INCREASING
OVER THE PAST HOUR. CLEARING WAS MOST PRONOUNCED FROM THE
BRAINERD LAKES REGION EAST NORTHEAST TO THE TWIN PORTS. 20Z
SATELLITE IMAGERY ALSO SHOWED CLEARING DEVELOPING OVER PARTS OF
THE ARROWHEAD WITH MORE HOLES OPENING OVER PORTIONS OF NORTHWEST
WISCONSIN. THE RAP HAS DONE A DECENT JOB WITH THIS...AS EARLY RUNS
SHOWED AN ACCELERATION IN THE CLEARING BY LATE AFTERNOON. THERE
ARE QUESTIONS ON HOW MUCH ADDITIONAL CLEARING WILL OCCUR TONIGHT.
THE RAP AND NAM SUGGEST CLOUDS MAY NOT CLEAR OVER PARTS OF FAR
NORTHERN MINNESOTA OR WILL MOVE BACK IN OVERNIGHT AS THE FLOW
VEERS TO NORTHEAST. WE DID INCREASE CLOUD COVER OVER
NORTHERN/NORTHEAST MINNESOTA TONIGHT...BUT DID NOT GO AS HIGH AS
THE RAP WOULD SUGGEST AT THIS TIME. THE AMOUNT OF CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TONIGHT...AND THEY MAY HAVE TO
BE ADJUSTED THROUGH THE EVENING AS CLOUD TRENDS BECOME CLEARER.
IF THE LOWER CLOUDS DO DEVELOP TONIGHT...THEY ARE EXPECTED TO THIN
THROUGH THE DAY BUT SOME CUMULUS DEVELOPMENT IS THEN EXPECTED.
MORE CLOUDS WILL DEVELOP DUE TO A SHORTWAVE AND AREA OF FGEN
FORCING...MAINLY OVER FAR NORTHERN MINNESOTA DURING THE AFTERNOON. AT THIS
TIME...IT DOES NOT APPEAR THE FORCING WILL BE STRONG ENOUGH FOR
PRECIP TO DEVELOP. HIGHS ARE EXPECTED TO RANGE FROM THE UPPER
FIFTIES TO MIDDLE SIXTIES...WARMEST FAR SOUTH. IT WILL BE COOLER
AROUND LAKE SUPERIOR WITH AN ONSHORE FLOW.
A LARGE AREA OF LOW PRESSURE WILL APPROACH FROM THE SOUTH SATURDAY
NIGHT. MOST AREAS WILL REMAIN DRY...BUT FAR SOUTHERN AREAS MAY SEE
SOME RAIN LATE. WINDS WILL BE INCREASING THROUGH THE NIGHT AROUND
LAKE SUPERIOR DUE TO INCREASING PRESSURE FALLS AHEAD OF THE LOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 321 PM CDT FRI MAY 8 2015
STRONG WARM ADVECTION AHEAD OF A DEEP LOW PRESSURE AREA WILL CREATE
A STRONG AND ACTIVE BAROCLINIC ZONE OVER MUCH OF THE FORECAST AREA
BEGINNING SATURDAY NIGHT AND CONTINUING INTO MONDAY. THIS RAIN
GO-ROUND IS SOMEWHAT SIMILAR TO OUR PAST RAIN...WITH THE STRONG WARM
AIR ADVECTION AND LOW LEVEL JET CAUSING WIDESPREAD RAIN TO SPREAD
NORTH. AS THE SFC LOW PASSES EAST...A COLD FRONT WILL MOVE THROUGH
MONDAY AFTERNOON AND EVENING. THE DIFFERENCE IS THAT THIS LOW COMING
UP IS MUCH STRONGER. AS A RESULT THE EAST WINDS THAT WILL ROTATE
AROUND THE LOW WILL BE MUCH STRONGER. WITH THE LOW FORECAST TO BE
SOMEWHERE OVER OR NEARING SOUTHERN MN SUNDAY AFTERNOON...THERE WILL
BE STRONG EAST WINDS ACROSS THE FORECAST AREA. WITH FORECAST 925-850
MB WINDS UP TO 50 KTS...LOOKS LIKE A BLUSTERY AND WAVY DAY ON LAKE
SUPERIOR. THE LOW`S MOVEMENT INTO NRN WI ON MONDAY WILL PROLONG THE
STRONG EAST WINDS OVER LAKE SUPERIOR...UNTIL TUESDAY MORNING WITH
THE LOW WELL EAST OF THE AREA.
THE UPPER LEVEL FLOW IS SPLIT WITH THE NORTHERN BRANCH NOT AFFECTING
US UNTIL LATER. ITS THE SOUTHERN BRANCH THAT WILL BRING THE DEEP TROF
ACROSS THE MIDWEST THROUGH TUESDAY. THE MODELS ARE IN GENERAL
AGREEMENT WITH THE SCENARIO...ALTHOUGH THE GFS IS MUCH MORE BULLISH
ON SUBSEQUENT PRECIPITATION AS THE NAM AND ECMWF BRING IN A DRY SLOT
TO CUT DOWN ON PRECIP AMOUNTS.
BY MONDAY NIGHT THERE WILL BE SOME COLD ENOUGH AIR TO HAVE SNOW.
WITH THE COLD AIR ADVECTION BEHIND THE LOW...WE WILL SEE COLUMN TEMPS
TO PLUMMET WELL BELOW FREEZING AND BELOW THE ICE CRYSTAL TEMPS.
ANOTHER LOW WILL APPROACH WEDNESDAY AFTERNOON AND BRING ANOTHER
CHANCE OF SHOWERS THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1246 PM CDT FRI MAY 8 2015
MVFR CIGS WILL IMPROVE TO VFR... SCATTERED CLOUDS... BETWEEN 20Z AND
22Z. MOST OF THE SITES WILL REMAIN SKC OVERNIGHT...HOWEVER...THERE
COULD BE SOME SPOTTY MVFR CIGS AFTER 08Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 55 39 42 / 10 10 10 70
INL 36 58 37 52 / 0 10 10 40
BRD 40 64 43 48 / 0 0 20 80
HYR 41 64 41 54 / 10 0 10 70
ASX 41 53 36 48 / 10 10 10 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...CLC
AVIATION...CLC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
654 PM CDT Sat May 9 2015
.SHORT TERM...(This Evening through Sunday)
Issued at 305 PM CDT SAT MAY 9 2015
Thunderstorm chances will increase through this evening and tonight
as a 50-60kt low level jet sets up along the MO/KS border and
overruns the stationary boundary near the I-44 corridor. Large
amounts of more moist air will spread into the region ahead of a
shortwave trough currently over central OK. Short term forecast
progs show K-index values around 40, well over the baseline of 30
generally needed for heavy rainfall. We`re also seeing tall and
skinny CAPE on RUC forecast soundings. With fairly saturated soils
from previous two nights of rainfall, will be issuing a Flash
Flood Watch for areas along and west of an Osceola to Cassville to
Gainesville line through 1 AM Monday. Later shifts may need to
modify areal coverage and timing.
Severe storm threat will remain on the lower end for hail and
straight line winds, but not zero. Better instability and more
favorable vertical wind shear for rotating storms will remain to our
west, in closer proximity to the main upper low pressure system over
the four corners region.
With better instability and upper level dynamics ahead of the
upper low which finally ejects to the northeast into the central Plains,
severe threat will be higher on Sunday afternoon/evening.
.LONG TERM...(Sunday Night through Saturday)
Issued at 305 PM CDT SAT MAY 9 2015
As the upper low continues to shift northward into the upper
Midwest, a cold front will finally push east of the region Monday
morning and bring a much drier and slightly cooler air mass into
the MO Ozarks/SE KS. We may see a few lingering showers over our
far eastern counties, so will keep storms in the forecast east of a
Warsaw to Cassville line through the morning, and east of a Rolla
to Gainesville line through the afternoon.
Surface high pressure will remain over the region through
Wednesday before another lee side trough sets up over the southern
Rockies ahead of an upper low moving into the southern CA coast
late next week. So expect increasingly stormy conditions from late
next week into the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 648 PM CDT SAT MAY 9 2015
For the KSGF/KJLN/KBBG tafs: Upper level disturbances will
continue to produce periods of showers/tstms with MVFR brief IFR
conditions at times through the taf period. A general lowering of
ceilings will be possible late tonight Sunday morning 10z-16z with
low level cooling and increased moisture. Hard to pinpoint times
of showers/tstms/convection so taking a fairly broad brush on rain
chances.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH through late Sunday night FOR MOZ066-067-077-
078-088-089-093>095-101>105.
KS...FLASH FLOOD WATCH through late Sunday night FOR KSZ073-097-101.
&&
$$
SHORT TERM...Terry
LONG TERM...Terry
AVIATION...DSA
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1149 PM CDT Thu May 7 2015
.UPDATE...
Issued at 953 PM CDT THU MAY 7 2015
Based on last several runs of the HRRR model and the 00Z NAM think
we`ll see additional more elevated convection form from central KS
through west central MO as the cold front sags southeast. This will
likely yield occasional rounds of moderate intensity rainfall. Not
expecting flash flooding type rains but more like ponding of water or
minor nuisance type urbanized flooding. Will increase PoPs to
categorical over the west central counties with some expansion to the
northeast and southwest. Have also increased Friday morning PoPs
over the southwestern third of the CWA.
&&
.DISCUSSION...
Issued at 408 PM CDT THU MAY 7 2015
Little change to the forecast was made in this package, as the
looming threat of multiple rounds of thunderstorms - some severe,
some non-severe...some with persistent heavy rain, some with passing
showers - over the next few days, culminating with a couple days of
likely severe weather through the weekend.
For the rest of the day on Saturday the surface cold front is
currently located roughly from KOMA to KLBL by way of KGBD. Some
weak showers and thunderstorms have formed along this boundary
across Kansas, SE Nebraska, and SW Iowa. Along and just ahead of
this boundary ML CAPE values approaching 1500 J/Kg are present, so
these storms could exhibit some robust updraft potential. The main
limiting factors for severe weather is the deep layer effective
shear, which is currently around 20 kts. With decent instability and
marginal shear it is unlikely that any severe weather occurs with
this activity, but it`s conceivable that an isolated cell or two
could demonstrate some hail up to quarter sized and/or an isolated
wind gust or two around 60 mph. Out ahead of the slowly moving cold
front in the warmer air a few showers and thunderstorms are ongoing,
and this appears to be in response to a very weak impulse in the
midlevels. Deeper in the warm air instability values are actually a
bit weaker than nearer to the cold front, and deep layer effective
shear is minimal, so severe risk across southern and central
Missouri is rather low.
Overnight tonight the boundary will sag southward and set up
residence in the forecast area, likely somewhere between HWY 36 and
I-70 somewhere. Showers and thunderstorms will fire off that
boundary through a good portion of the overnight hours, bringing
several periods of rain to that area. Then by Friday afternoon the
boundary will lift north and could fire off a few rounds of
precipitation. With ML CAPE values south of the boundary in the 1000
to 1500 J/kg range there will be enough instability to get robust
updrafts, and effective shear values will even be a bit higher than
Thursday, with 0-6 km shear vectors out of the southwest around 30
kts. With shear vectors likely parallel to the boundary, it`s
possible that storms go up on the boundary, then follow each other
along that boundary. Expect robust severe weather to form in the
southern plains, and depending on the track of the upscale growth of
those storms we could see a rather wet overnight period on Friday
night into Saturday morning.
Saturday and Sunday bring with it a rather large bit of uncertainty.
By Saturday morning the boundary will lift back to the north and
could set up in northern Missouri, or perhaps north of the IA/MO
border. This boundary could be the focus for some convection on
Saturday, despite the main area of afternoon/evening convection
being in the central and southern plains. Instability on Saturday
will be rather high with ML CAPE values approaching 2000 to 2500
J/kg. Forecast hodographs along that boundary look to be rather
impressive with good clockwise curvature. Should any storms be able
to go up away from the dryline - which will be set up in western
KS/OK - then they could end up being rather potent with some storms
becoming severe. Despite the uncertainty with the afternoon/evening
convection it appears more certain that the big convection over the
western plains will congeal into a series of convective systems and
move eastward toward the forecast area. This would likely bring at
the minimum a period of heavy rain overnight on Saturday, with
perhaps some gusty winds and hail.
The focus then turns to Sunday, when a more classic severe weather
set up moves into eastern Kansas and western Missouri. The large
trough over the western CONUS will eject out and bring with it lots
of mid level ascent. The surface dryline/pacific front will be on
the doorstep of the forecast area when the trough ejects out, and
this could kick off a round of widespread robust convection.
Instability and shear parameters will likely be sufficient for
scattered to widespread severe weather. Details regarding the
weekend rounds of strong to severe storms will depend strongly on
mesoscale influences, thusly details about how everything plays out
will depend on signals that appear closer to the event. At any rate
with high PW values and multiple chances for convective systems to
move through over the next several days there still exists the
potential for several inches of rain across a widespread area. With
antecedent conditions being somewhat soggy - characterized by
several days of light to moderate rain - there will exist the
possibility for some flash flooding as well as stream flooding
across the area.
By Monday the pacific front will move through the area, and perhaps
clear the forecast area to the east, across central Missouri. There
could be some initiation of Monday cells across the far eastern edge
of the CWA on Monday, but with dry air working into the area, the
chances for precip on Monday should be confined to that area, with
dry conditions west of the boundary.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1142 PM CDT THU MAY 7 2015
Precipitation will continue off an on through the period as storms
develop to the west. Initially, expecting some nearby convective
activity to continue overnight with light rain showers steadily
pushing eastward. A frontal boundary will sweep through the area in
the morning, which will weaken the convective activity, though
periodic rain showers will linger. Expecting to see a dry period
through the afternoon, though some models have indicated at isolated
convection during this time frame. Toward the very end of the period,
will likely see further development of thunderstorm activity as winds
continue to veer to the east.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
DISCUSSION...Leighton
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
618 PM CDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
TONIGHT AND TOMORROW...FORECASTING CONCERNS CENTER ON
THE SEVERE THREAT THIS EVENING...SNOW THREAT IN THE WEST AND
NORTHWEST OVERNIGHT TONIGHT AND SUNDAY...AS WELL AS THE THREAT FOR
HEAVY RAIN AND POSSIBLE FLASH FLOODING CONCERNS. A VIGOROUS UPPER
LEVEL LOW...CURRENTLY OVER SOUTH CENTRAL COLORADO...WILL MIGRATE
INTO NORTHEASTERN COLORADO THROUGH 12Z SUNDAY...BEFORE LIFTING INTO
NORTHERN NEBRASKA BY 00Z MONDAY. IN ASSOCIATION WITH THIS
FEATURE...STRONG TO POSSIBLY SEVERE THUNDERSTORMS WILL BE POSSIBLE
THIS EVENING...FOLLOWED BY THE THREAT FOR HEAVY RAIN
OVERNIGHT...THEN ACCUMULATING SNOWS IN THE EASTERN PANHANDLE AND
NORTHWESTERN SANDHILLS OVERNIGHT. FIRST FOR THE SEVERE THREAT
TONIGHT...A BULGING DRYLINE WILL PUSH FROM SWRN KS INTO NWRN KS BY
06Z SUNDAY. THUNDERSTORMS WILL INITIATE ALONG THIS FEATURE AND
QUICKLY LIFT NORTH INTO SWRN AND SOUTH CENTRAL NEBRASKA. WITH THE
LOW CLOUDS AND COOL CONDS TODAY...THE SEVERE THREAT CONTINUES TO
DIMINISH ACROSS THE SWRN CWA. WITH THIS KIND OF SETUP...DRYLINE TO
THE SOUTH...WARM FRONT TO THE SOUTH...THIS IS TYPICALLY A GOOD SETUP
FOR LARGE HAIL AND THIS WILL BE THE MAIN HAZARD MENTIONED IN THE
HWO. THEN THERE IS THE THREAT FOR SNOW IN THE PANHANDLE AND
NORTHWESTERN SANDHILLS LATER THIS EVENING. ALREADY AS OF 2 PM THIS
AFTERNOON...LIGHT SNOW WAS BEING REPORTED AT CHADRON...WHICH WAS
EARLIER THAN ANTICIPATED WITH THE CURRENT FORECAST. ALREADY HAVE
INCREASED SNOW ACCUMULATIONS IN THE PINE RIDGE AND NERN
PANHANDLE...TO REFLECT AN EARLIER CHANGEOVER OF SNOW. THESE HIGHER
ACCUMS APPG A FOOT WILL BE INCORPORATED IN THE UPDATE OF THE WINTER
STORM WARNING FOR SHERIDAN COUNTY TO BE ISSUED WITH THE AFTERNOON
PACKAGE. SOUTH AND EAST OF SHERIDAN COUNTY...SNOW IS EXPECTED AS
WELL...HOWEVER A MUCH TIGHTER ENVELOPE FOR ACCUMS EXISTS GIVEN
INCREASED MOISTURE AND WARMER TEMPS EXPECTED OVERNIGHT. NO
DOUBT...THE RAIN/SNOW LINE WILL BE VERY TIGHT AND AS IT STANDS RIGHT
NOW...THIS FEATURE RUNS RIGHT THROUGH SHERIDAN COUNTY. TURNING TO
THE HEAVY RAIN THREAT TONIGHT...STRONG MOISTURE ADVECTION CONTINUES
FROM THE SOUTHERN PLAINS INTO NEBRASKA PER 300K MOISTURE TRANSPORT
VECTORS. PW/S WILL INCREASE BY MID EVENING TO 1.1 INCHES AT NORTH
PLATTE...WHICH IS NEAR RECORD FOR THIS TIME OF YEAR. THIS MOISTURE
WILL SHIFT QUICKLY NORTH OVERNIGHT AS THE UPPER LEVEL LOW PUSHES
INTO NORTHEASTERN COLORADO...HOWEVER PW/S WILL STILL BE A HALF TO
2/3RDS OF AN INCH EVEN BEHIND THE DEEPEST AREA OF MOISTURE WHICH
SHIFTS INTO EASTERN NEBRASKA AND SERN SOUTH DAKOTA BY SUNDAY
MORNING. WIDESPREAD PRECIPITATION IS EXPECTED OVERNIGHT...WITH THE
MOST PERSISTENT AREAS TRANSITIONING FROM THE PANHANDLE INTO SWRN AND
CENTRAL NEBRASKA BY LATE EVENING. THIS IS IN RESPONSE TO EXPECTED
CONVECTIVE DEVELOPMENT OVER NORTHWESTERN KS. THE LATEST HRRR AND THE
NAM SOLN FROM THIS MORNING TO A LESSER DEGREE...FOLLOW THIS TREND OF
HEAVIER RAIN SHIFTING INTO SWRN AND CENTRAL NEBRASKA LATER THIS
EVENING...WITH DECREASED QPF IN THE WEST. THIS LULL WILL BE
TEMPORARY HOWEVER. LOOK FOR PCPN TO INCREASE SUNDAY MORNING IN THE
WEST AS DEFORMATION PCPN DEVELOPS ON THE BACK SIDE OF THE EXITING
LOW. THE LATEST 3 HR FLASH FLOOD GUIDANCE IS LESS THAN 1.5 INCHES IN
THE SERN PANHANDLE...KEITH AND PERKINS COUNTIES. THIS AREA HAS
LARGELY ESCAPED THE HEAVY RAIN EARLIER THIS MORNING AND THIS
AFTERNOON. WITH THE HRRR INDICATING HEAVIER RAIN EAST OF THESE
AREAS...WILL FORGO ISSUANCE OF A FLASH FLOOD WATCH FOR THESE AREAS.
FURTHER EAST...3 HR FFG IS AROUND 2 INCHES FOR CUSTER COUNTY SOUTH
OF THE SANDHILLS. AGAIN HRRR QPF/S ARE AROUND 1 TO 2 INCHES IN
CUSTER COUNTY TONIGHT...WHICH IS BELOW FFG SO WILL FORGO A FLASH
FLOOD WATCH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
MODELS VARY SOME WITH AMOUNT OF COLD AIR MOVING THROUGH NORTHERN
NEBRASKA SUNDAY NIGHT AND HAVE GONE WITH COLDER SOLUTION OF THE
NAM. DEFORMATION ZONE WILL CONTINUE TO LIFT THROUGH THE NORTHERN
NEBRASKA SANDHILLS WITH A MIX OF RAIN...RAIN SNOW MIX AND SNOW.
HAVE A COUPLE OF INCHES OF ACCUMULATION WITH THE LIFT ASSOCIATED
WITH THE DEFORMATION ZONE...OVER A VERY SMALL PORTION OF NORTHERN
CHERRY COUNTY. WINDS WILL STAY UP THROUGH MONDAY WITH PRECIP
ENDING THROUGH THE MORNING. LOW TEMPERATURES IN THE 20S NORTHWEST
TO THE MID 30S NORTH CENTRAL...ONEILL. HIGHS IN THE 40S WEST AND
THE 50S SOUTHWEST AND EAST. CLEARING SKIES THROUGH THE DAY WITH
MOSTLY CLEAR SKIES OVER NIGHT. WINDS FALLING OFF AND BECOMING
SOUTH OVER NIGHT WILL ALLOW TEMPERATURES TO FALL TO AROUND
FREEZING. HAVE HELD OFF ON HIGHLIGHTS FOR NOW WITH CURRENT
HIGHLIGHTS OUT. TEMPERATURES REBOUND MONDAY AND TUESDAY AS RIDGE
EXPANDS WEST. WEAK WAVE TO MOVE THROUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING SLIGHT CHANCES RETAINED FOR SOUTHWEST INTO NORTH
CENTRAL NEBRASKA. CHANCES FOR PRECIPITATION RETURN TO THE FORECAST
THURSDAY AND CONTINUE THROUGH THE END OF THE PERIOD AS ENERGY
EJECTS FROM A CLOSED LOW OFF THE PACIFIC COAST AND TEMPERATURES
RISING INTO THE 70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 607 PM CDT SAT MAY 9 2015
A POWERFUL UPPER LEVEL LOW WILL TRACK ACROSS EASTERN COLORADO INTO
WESTERN NEBRASKA TONIGHT INTO SUNDAY. ABUNDANT LOW LEVEL CLOUDS
AND OCCASIONAL RAIN WILL CONTINUE OVER THE NEXT 12 TO 24 HOURS
WITH IFR CIGS EXPECTED AT THE KLBF AND KVTN TERMINALS. SOME LIFR
CIGS ARE POSSIBLE AT THE KLBF TERMINAL LATE TONIGHT INTO SUNDAY
MORNING WITH CIGS BLO 500 FT AGL. CIGS WILL IMPROVE SAT AFTERNOON
TO 1000 TO 2000 FT AGL AT THE KLBF TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SAT MAY 9 2015
THE ONGOING LARGE SCALE AND LONG DURATION HEAVY PRECIP EVENT OVER
THE HIGH PLAINS WILL LEAD TO FLOODING CONCERNS NEXT WEEK ON THE
SOUTH PLATTE RIVER IN SOUTHWEST NEBRASKA INCLUDING
DEUEL...KEITH...AND LINCOLN COUNTIES. AS OF SATURDAY MORNING THE
SOUTH PLATTE RIVER IS ALREADY EXPERIENCING ABOVE NORMAL FLOWS DUE TO
SNOW MELT RUNOFF IN THE FRONT RANGE MOUNTAINS OF COLORADO. LATEST
RIVER FORECAST PROJECTIONS SHOW AN INCREASING THREAT FOR SIGNIFICANT
FLOODING BY THE SECOND HALF OF NEXT WEEK. HOWEVER...HIGH UNCERTAINTY
STILL REMAINS IN THE AMOUNT OF OBSERVED/FORECAST RAINFALL IN
NORTHEAST COLORADO AND WESTERN NEBRASKA...AS WELL AS HOW IT WILL
IMPACT UPSTREAM FLOWS ON THE SOUTH PLATTE RIVER. RIVER FORECASTS
WILL BE CLOSELY MONITORED AND UPDATED AS MORE INFORMATION BECOMES
AVAILABLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM MDT SUNDAY
FOR NEZ022-023-056-094.
WINTER STORM WARNING UNTIL 6 PM MDT SUNDAY FOR NEZ004.
&&
$$
SHORT TERM...CLB
LONG TERM...POWER
AVIATION...CLB
HYDROLOGY...MARTIN
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
627 PM PDT SAT MAY 9 2015
.SYNOPSIS...SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED AROUND THE
AREA THROUGH TONIGHT ESPECIALLY ACROSS SOUTHERN NEVADA AND FAR
NORTHERN MOHAVE COUNTY. OTHERWISE EXPECT A WARMING TREND INTO THE
WORKWEEK. A DRY SYSTEM WILL CROSS THE AREA TUESDAY BRINGING BREEZY
CONDITIONS. ANOTHER SYSTEM MAY IMPACT THE AREA ON THURSDAY WITH MORE
WIND AND POSSIBLY RESULT IN A SHOWER IN THE SOUTHERN SIERRA. SHOWER
CHANCES THEN SPREAD TO PORTIONS OF SOUTHERN NEVADA AND NORTHWEST
ARIZONA FRIDAY.
&&
.UPDATE...SHOWERS/THUNDERSTORMS DEVELOPED THIS EVENING FARTHER WEST
THAN PREVIOUSLY FORECAST...OVER SOUTHERN INYO AND NORTHWEST SAN
BERNARDINO COUNTIES. LATEST HRRR SUPPORTS THAT ACTIVITY CONTINUING
AND MOVING SOUTH THROUGH 06Z. I UPDATED TO INCREASE POPS AND TO
MENTIONS A CHANCE OF THUNDERSTORMS ACROSS SOUTHERN INYO AND MUCH OF
SAN BERNARDINO COUNTIES FOR THE EVENING. -HARRISON-
&&
.PREV DISCUSSION...
240 PM PDT SAT MAY 9 2015
.SHORT TERM...TODAY THROUGH MONDAY NIGHT.
THE CENTER OF THE MIDLEVEL CIRCULATION ASSOCIATED WITH OUR DEPARTING
LOW PRESSURE SYSTEM IS CURRENTLY LOCATED OVER THE FOUR-CORNERS
REGION. LINGERING ENERGY AND MOISTURE ON THE WESTERN SIDE OF THE LOW
WILL CONTINUE TO ROTATE GENERALLY NORTH-NORTHWEST TO SOUTH-SOUTHEAST
ACROSS THE FORECAST AREA THIS AFTERNOON AND EVENING. ALREADY SEEING
SHOWERS REDEVELOP ALONG THE TERRAIN THIS AFTERNOON ACROSS SOUTHERN
NEVADA, NORTH AND WEST OF LAS VEGAS. THIS IS HINTED AT IN THE LATEST
HIRES MODELS, PARTICULARLY THE HRRR. ANY SHOWERS OR THUNDERSTORMS
THAT FORM OVER THE SPRING MOUNTAINS AND SHEEP RANGE HAVE THE
POTENTIAL TO MOVE INTO AT LEAST A PORTION OF THE LAS VEGAS VALLEY
LATE THIS AFTERNOON OR EARLY THIS EVENING AS THE STEERING FLOW
PUSHES THEM. HAVE RETAINED AT LEAST A SLIGHT CHANCE OF ACTIVITY IN
THE LAS VEGAS VALLEY FOR THESE TIME PERIODS, HIGHER CHANCE NORTH AND
WEST. ANY SHOWERS WOULD ALSO PRODUCE LOCALLY GUSTY WINDS TO ABOUT 35
MPH OR SO, WITH GENERALLY A NORTHWEST COMPONENT FAVORED.
THIS LOW PRESSURE SYSTEM WILL PUSH FARTHER NORTHEAST TOMORROW, AS
RIDGING BUILDS IN. SOME FORCING MAY SWING OVER OUR EASTERN AREAS
DURING PEAK HEATING HOURS TOMORROW. BELIEVE MOST IF NOT THE ENTIRE
AREA WILL BE DRY SUNDAY. HOWEVER, WITH SOME LINGERING MOISTURE
ACROSS NORTHERN MOHAVE COUNTY AND THE PRESENCE OF THIS FORCING HAVE
DECIDED TO KEEP ISOLATED SHOWER CHANCES FOR THIS REGION. DRY
CONDITIONS FULLY TAKE HOLD FOR MONDAY, AS WE SIT AHEAD OF ANOTHER
LOW PRESSURE TROUGH. THE UPPER LOW ASSOCIATED WITH THIS FEATURE IS
EXPECTED TO PUSH ONSHORE ACROSS OREGON OR NORTHERN CALIFORNIA, WITH
THE TROUGH AXIS DRAPED SOUTHWARD. WE WILL SEE A DECENT SOUTH-
SOUTHWEST FLOW ALOFT LEADING TO BREEZY CONDITIONS MONDAY, WITH WIND
GUSTS OF 15-25 MPH POSSIBLE.
AS FOR TEMPERATURES, THE WARMING TREND STARTS TODAY. TEMPERATURES AS
OF THIS WRITING WERE ALREADY WARMER THAN YESTERDAY`S HIGHS. THE
RIDGE BUILDING IN TOMORROW WILL ALLOW FOR ADDITIONAL WARMING, WITH
TEMPERATURES CLIMBING CLOSE TO NORMAL FOR THIS TIME OF YEAR. THE
GUSTY SOUTH-SOUTHWEST WINDS MONDAY WILL AID MIXING AND RESULT IN
HIGHS OF 90 TO 100 DEGREES IN THE LOWER ELEVATIONS OF THE MOJAVE
DESERT.
.LONG TERM...TUESDAY THROUGH SATURDAY.
AN ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEK AND INTO
NEXT WEEKEND AS PACIFIC SHORTWAVE ENERGY ROLLS INTO THE WEST COAST.
MODELS HAVE THEIR DIFFERENCES BUT GENERALLY FORECAST LOW PRESSURE
MOVING INTO OREGON/NORTHERN CAL ON TUESDAY AND WEAKENING AS IT LIFTS
OFF TO THE NORTHEAST TUESDAY NIGHT. THIS SYSTEM WILL RESULT IN SOME
ENHANCED BREEZES ACROSS THE AREA AND HIGH CLOUDS BUT LITTLE TO NO
ACCUMULATING PRECIPITATION IS EXPECTED. WEDNESDAY LOOKS LIKE THE
QUIETEST WEATHER DAY OF THE WEEK OVER THE SOUTHWEST AS THE
ATMOSPHERE GEARS UP FOR THE NEXT PACIFIC SYSTEM THAT WILL BRING
COOLER, UNSETTLED WEATHER CONDITIONS TO THE REGION HEADING INTO THE
WEEKEND. MODELS DISAGREE OVERALL ON THE FINER DETAILS THIS FAR OUT
BUT THEY DO AGREE THIS LARGE...COMPLEX LOW PRESSURE SYSTEM WILL BE
WITH US FOR AN EXTENDED STAY THAT COULD HAVE LINGERING EFFECTS
LASTING THROUGH THE WEEKEND AND POSSIBLY LONGER. OF COURSE, HOW AND
WHEN THE VARIOUS COMPONENTS OF THE LOW INTERACT WILL DETERMINE THE
TIMING, PLACEMENT, AMOUNTS AND TYPE OF PRECIPITATION AND HOW STRONG
WINDS WILL EVENTUALLY BE.
TEMPERATURES ON TUESDAY ARE FORECAST TO BE RIGHT AT NORMAL BUT WILL
THEN COOL THROUGH THE WEEK...ENDING UP WELL BELOW NORMAL BY FRIDAY
AND SATURDAY. ANYONE WITH OUTDOOR PLANS FOR NEXT FRIDAY AND THE
WEEKEND SHOULD MONITOR FORECASTS ESPECIALLY AS THAT TIME PERIOD
DRAWS CLOSER.
&&
.AVIATION...FOR MCCARRAN...SOUTHEAST WINDS ARE EXPECTED TO
TRANSITION TO WESTERLY, GENERALLY LESS THAN 10 KTS WHILE CLOUDS WILL
ADVANCE INTO THE VALLEY WITH BASES AOA 6-8K FEET. SHRA AROUND KINS
WILL MOVE SOUTHEAST, WITH THE POSSIBILITY OF ADDITIONAL DEVELOPMENT
IN THE SPRING MTS AND SHEEP RANGE. THIS ACTIVITY MAY PUSH INTO THE
VALLEY THIS EVENING. IF ANYTHING CROSSES THE AIRPORT COMPLEX ITSELF
THE MOST LIKELY TIME STILL LOOKS TO BE BETWEEN 00Z AND 03Z, WHEN
BASES COULD LOWER TO 5K-7K FEET. THIS WOULD ALSO FAVOR A WEST TO
NORTHWEST WIND WHICH MAY GUST. ONCE THIS LINE OF ENHANCED CLOUDS AND
ANY SHRA PASS THROUGH WINDS WOULD FAVOR NORTHEAST AT 5-10 KTS BEFORE
BECOMING LIGHT AND VARIABLE. LIGHT AND VARIABLE WINDS SHOULD PREVAIL
THROUGH SUNDAY MORNING. WINDS WILL THEN FAVOR A NORTHEAST WIND
GENERALLY 8 KTS OR LESS STARTING AROUND 17Z.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WINDS WILL MAINLY FOLLOW TYPICAL DIURNAL DIRECTIONAL
TRENDS AT 6-12 KTS WITH LOCAL GUSTS OF 15-20 KTS AT KDAG. NORTH
WINDS WILL INCREASE IN THE OWENS VALLEY THIS AFTERNOON AND EARLY
EVENING TO 15-22 KTS WITH GUSTS TO 30 KTS. SHRA AND ISOLATED TSRA
CAN BE EXPECTED ACROSS LINCOLN, ESMERALDA, CENTRAL NYE, CLARK, AND
NORTHERN MOHAVE COUNTIES TODAY. ISOLATED SHRA/TSRA WILL ALSO BE
AROUND IN THE HIGHER TERRAIN OF INYO COUNTY THROUGH THIS EVENING.
GUSTY AND ERRATIC WINDS ARE POSSIBLE NEAR ANY SHRA/TSRA. SCT-BKN
CLOUDS AOA 4K-8K FEET. WINDS WILL SHIFT TO THE WEST TO NORTHWEST AND
EVENTUALLY NORTH AT 5-10 KTS ACROSS MUCH OF THE AREA LATER TONIGHT.
&&
.SPOTTER INFORMATION STATEMENT....SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...PADDOCK
LONG TERM...SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1158 PM MDT THU MAY 7 2015
.AVIATION...
06Z TAF CYCLE
DRY LINE WITH GULF MOISTURE IMMEDIATELY BEHIND IT HAD ADVANCED
INTO ROUGHLY THE EAST HALF OF THE EASTERN PLAINS. THIS WILL LIKELY
ALLOW SOME PATCHY MVFR OR EVEN IFR CIGS AND POSS FOG INTO THIS
AREA...ROUGHLY NEAR AND ESPECIALLY EAST OF A LINE FROM CAPULIN TO
ROSWELL. THIS AREA ALSO WILL HAVE A SLIGHT CHANCE OF DEVELOPING
ISOLATED SHRA/TSRA AS WELL BETWEEN APPROX 08Z AND 13Z. GREATEST
RISK OF EITHER OCCURRENCE AT A TERMINAL SITE WILL BE AT TCC. WX
CONDITIONS FRI SIMILAR TO THU...EXCEPT WINDS SFC AND ALOFT WILL BE
STRONGER THAN TODAY AND MAY GUST BETWEEN 30 AND 40 KTS ACROSS SW
AND FAR WEST CENTRAL NM BETWEEN 19Z AND 24Z FRI. ISOLATED MID AFTN
THROUGH EVE SHRA AND TSRA...PERHAPS A FEW STRONG ONES WITH HAIL
AND STRONG WINDS...POSS NEAR TX AND CO LINE.
43
&&
.PREV DISCUSSION...924 PM MDT THU MAY 7 2015...
.UPDATE...
DRYLINE IS RETREATING QUICKLY THIS EVENING AND IF HRRR/RUC PROGS
ARE CORRECT...WILL RETREAT AT LEAST TO A KRTN TO SANTA ROSA TO
KROW LINE. HAVE INCREASED DEWPOINTS AND LOW TEMPS SEVERAL DEGREES
EAST OF THE DRYLINE OVERNIGHT. IN ADDITION TO A STRAY SHOWER OR
TSTM IN THESE AREAS...THERE IS AN INCREASING CHANCE THAT FOG WILL
DEVELOP...SO HAVE ADDED FOG AFTER 06Z IN THESE LOCATIONS. THE LOW
LEVEL MOISTURE AND FOG WILL MIX OUT BY MID MORNING AS
SOUTHWESTERLY WINDS RAMP BACK UP.
ELSEWHERE...A FEW THUNDERSTORMS HAVE FORMED ACROSS SE AZ ON THE
NOSE OF AN UPPER LEVEL JET. THE NOSE OF THE JET IS PROGGED TO
MOVE INTO WESTERN NM OVERNIGHT AS THE UPPER LOW OVER CALI SHIFT
EASTWARD...AND THE LATEST HRRR SUGGEST A FEW SHOWERS OR
THUNDERSTORMS WILL MAKE IT INTO NM. SO HAVE ADDED SOME 10-POPS
ACROSS THE WEST AFTER 06Z TO ACCOUNT FOR THIS.
UPDATES OUT SHORTLY.
34
&&
.PREV DISCUSSION...345 PM MDT THU MAY 7 2015...
...CORRECTED TYPOGRAPHICAL ERROR...
.SYNOPSIS...
THE DRYLINE INVADED EASTERN NEW MEXICO LAST NIGHT...BUT HAS NOW
DRIFTED BACK TOWARD THE NEW MEXICO-TEXAS BORDER. THIS BOUNDARY
WHICH SEPARATES DRY AIR TO THE WEST AND MOIST UNSTABLE AIR TO THE
EAST CAN OFTEN TRIGGER SHOWERS AND STORMS...AND COULD DO SO LATE
THIS AFTERNOON AND TONIGHT. ADDITIONAL STORMS MAY ALSO INVADE
NORTHEASTERN NEW MEXICO AS A COLD FRONT SAGS NEAR THE AREA.
OTHERWISE THERE WILL BE JUST A FEW STRAY SHOWERS AND STORMS OVER
THE NORTH CENTRAL SECTION OF NEW MEXICO THIS EVENING. A LOW
PRESSURE SYSTEM WILL LEAVE CALIFORNIA ON FRIDAY...DRIFTING INTO
ARIZONA WHILE BRINGING BREEZY TO WINDY CONDITIONS TO NEW MEXICO. A
FEW STRONG STORMS WILL REMAIN POSSIBLE IN THE NORTHEASTERN CORNER
OF NEW MEXICO FRIDAY AFTERNOON AND EVENING AS THE AFOREMENTIONED
FRONT STALLS. THE WINDS ARE EXPECTED TO STRENGTHEN INTO SATURDAY
AS THE LOW PRESSURE SYSTEM SWEEPS OVER THE FOUR CORNERS REGION AND
INTO COLORADO. PRECIPITATION CHANCES WILL INCREASE WITH THE
PASSAGE OF THIS SYSTEM SATURDAY...AND WILL LINGER INTO SUNDAY WITH
THE NORTH CENTRAL TO NORTHWESTERN SECTIONS OF NEW MEXICO REMAINING
THE FAVORED AREAS.
&&
.DISCUSSION...
DRYLINE MADE AN APPEARANCE THIS MORNING IN THE EARLY
MORNING...IGNITING ONLY A FEW ELEVATED SHOWERS/STORMS IN EAST
CENTRAL NM BEFORE THEY QUICKLY ESCAPED INTO TX. THE DRYLINE HAS
SLOSHED BACK TO THE EAST SOME WITH SOME DEWPOINTS HAVING LOWERED
BACK INTO THE 30S AND 40S AROUND KTCC...KCVN...KCVS...AND
VICINITY. SUSPECT NO STORMS WILL BE ABLE TO DEVELOP IN EASTERN NM
LATE THIS AFTERNOON...BUT COULD DEVELOP THIS EVENING AS THE
DRYLINE SLOSHES BACK WEST. HAVE KEPT 20 PERCENT POPS ALONG THE
EASTERN TIER OF COUNTIES TONIGHT TO ACCOUNT FOR THIS. AM ALSO
EXPECTING CONVECTION IN EASTERN CO TO BECOME BETTER ORGANIZED AND
MORE WIDESPREAD...POTENTIALLY ENHANCING THE COLD POOL AND DRIVING
THE SURFACE FRONT INTO THE NORTHEASTERN CORNER OF NM THIS EVENING.
ANY STORMS THAT DO ENTER NORTHEAST WOULD HAVE BETTER CHANCES FOR
TURNING STRONG TO SEVERE WITH BETTER VEERING WIND PROFILES AND
HIGHER SHEAR.
AS UPPER LOW EXITS CA AND ENTERS AZ ON FRIDAY...STRONGER
SOUTHWESTERLIES ARE DRAWN OVER NM WHILE A SURFACE LOW BEGINS TO
DEEPEN. THE SURFACE LOW WILL NOT BE OPTIMALLY LOCATED FOR A VERY
STRONG WIND EVENT...BUT SUFFICIENT DEEP VERTICAL MIXING SHOULD
TRANSPORT SOME BREEZY TO WINDY CONDITIONS DOWN TO THE SURFACE
FRIDAY AFTERNOON. BEST FORCING FOR PRECIPITATION VIA DIFFLUENCE
ALOFT AND EVEN SOME OROGRAPHICS WILL BE PLACED OVER THE NORTHERN
TIER OF NM WHILE THE SURFACE FRONT WASHING OUT IN THE NORTHEAST
COULD ALSO INITIATE SOME STORMS IF IT TAKES ITS TIME RETREATING.
SATURDAY STILL APPEARS TO BE THE MORE DYNAMIC DAY WITH THE LOW
PROGRESSING QUICKLY OVER THE FOUR CORNERS AND THEN INTO CO. THIS
WILL DYNAMICALLY COOL THE ATMOSPHERE OVER NM WHILE SPREADING EVEN
STRONGER WINDS INTO THE STATE DUE TO STRONGER BELT OF WINDS ALOFT
WRAPPING THE BASE OF THE LOW AND A DEEPENING LEE SIDE SURFACE
CYCLONE IN EASTERN CO. STRONGEST WINDS HAVE BEEN BUILT INTO
NORTHEAST NM...AND AN ADVISORY OR OTHER HIGHLIGHTS MAY BE
NECESSARY. PRECIPITATION WILL FAVOR THE NORTH CENTRAL TO
NORTHWESTERN ZONES...BUT QPF IS NOT ALL THAT HIGH. HOWEVER...SNOW
LEVELS COULD LOWER TO 7000 TO 8000 FEET IN SOME AREAS
SATURDAY...WITH POTENTIAL FOR A COUPLE TO A FEW INCHES OF HIGH
ELEVATION SNOW ACCUMULATION. TEMPERATURES WILL FALL 5 TO 20
DEGREES BELOW EARLY MAY CLIMATOLOGY ON SATURDAY.
THE LOW WILL EXIT INTO THE GREAT PLAINS SUNDAY...BUT WRAP-AROUND
DYNAMICS WILL KEEP SOME PRECIPITATION GOING OVER THE NORTHERN
ZONES OF NM...ESPECIALLY IN THE NORTH CENTRAL TO NORTHWESTERN
ZONES. BREEZES WILL REDUCE IN SPEED CONSIDERABLY...BUT WILL STILL
BE QUITE BRISK. TEMPERATURES WILL REMAIN 5 TO 15 DEGREES BELOW
AVERAGE SUNDAY...AND A BACK DOOR FRONTAL INTRUSION IS STILL
ADVERTISED BY THE FORECAST MODELS FOR SUNDAY NIGHT.
WHILE A QUIETER DAY IS EXPECTED ON MONDAY WITH REBOUNDING
TEMPERATURES AND LIGHTER WINDS...MOISTURE AND WINDS WILL BE
STAGING FOR MORE ADVERSE AND UNSETTLED WEATHER FOR THE TUESDAY TO
WEDNESDAY PERIOD. WINDS WILL QUICKLY VEER SOUTHEASTERLY IN TX AND
INTO EASTERN NM...ADVECTING MOISTURE FROM THE GULF OF MEXICO.
HEALTHY COVERAGE OF SHOWERS AND STORMS...SOME OF WHICH COULD TURN
STRONG TO SEVERE...WILL BE SETTING UP INTO TUESDAY AND
WEDNESDAY...NAMELY EAST OF THE CENTRAL MOUNTAIN CHAIN.
52
&&
.FIRE WEATHER...
BREEZIER PATTERN NEXT COUPLE OF DAYS. ANOTHER MOISTURE INTRUSION
WILL IMPACT NORTHERN AREAS SATURDAY. A MORE POTENT MOISTURE
INTRUSION WILL BE POSSIBLE...FAVORING THE EASTERN HALF BY THE MIDDLE
OF NEXT WEEK. FIRE DANGER CONDITIONS ARE A MOSAIC DUE TO GREENUP
CONSIDERATIONS. DUE TO THE LACK OF A WIDESPREAD/SIGNIFICANT IMPACT
WEATHER EVENT...WATCHES/WARNINGS ARE NOT EXPECTED DURING THE NEXT 7
DAYS.
ISOLATED SHOWERS/THUNDERSTORMS...GENERALLY LIGHTER VARIETY WILL
CONTINUE TO FAVOR THE NORTHERN AND EASTERN TIER TODAY INTO THE
OVERNIGHT HOURS. HUMIDITY RECOVERIES WILL GENERALLY BE MODERATE TO
GOOD MOST AREAS TONIGHT.
UPTICK IN THE WIND WILL OCCUR ON FRIDAY AS A PACIFIC CLOSED LOW
EDGES CLOSER TO THE STATE. DRIER AIR FOUND IN THE MID LEVELS OF THE
ATMOSPHERE WILL GRADUALLY LIFT NORTHWARD OVER THE AREA AND BEGIN THE
DRYING PROCESS. A FEW LEFT OVER SHOWERS/STORMS COULD BE FOUND ACROSS
THE FAR NORTH. CURRENT GRIDS SHOW SOME STRONG WIND/LOW RH AND VARIED
HAINES 4 TO 6 VALUES ACROSS PORTIONS OF THE FORECAST AREA. MAIN
THREAT APPEARS TO BE ACROSS THE LOWER RIO GRANDE VALLEY AND BETWEEN
LAS VEGAS TO SANTA ROSA. DUE TO LESS ORGANIZATION AND VARIED FUEL
CONCERNS WILL NOT ISSUE A WATCH. HIGH TEMPERATURES ALSO APPEAR TO BE
NEAR NORMAL TO EVEN BELOW NORMAL ACROSS THE WESTERN/SOUTHERN TIER.
VENTILATION WILL BE EXCELLENT.
THE MODELS CONTINUE TO TREND A CLOSE LOW MOVING OVER THE NW HALF OF
THE FORECAST AREA ON SATURDAY. SHOWERS/STORMS WILL DEVELOP WITHIN
THE LOW PRESSURE CENTER AND PROVIDE SOME MODERATE WETTING RAIN
CHANCES ACROSS THE NW THIRD TO HALF. SOME MODERATE DRY SLOTTING WILL
IMPACT FAR SOUTHERN/EASTERN AREAS WITH CONTINUED BREEZINESS DUE TO
THE PASSAGE OF A COLD FRONT. TEMPERATURES WILL BE BELOW NORMAL AND
HAINES VALUES WILL BE LOWER DURING THE AFTERNOON PERIOD. CAN SEE
SOME STRONG WIND/LOW RH ALIGNMENT ACROSS FAR SOUTH CENTRAL AND EAST
CENTRAL/SOUTHEAST AREAS DURING SATURDAY AFTERNOON. ONCE AGAIN...WONT
ISSUE A WATCH FOR THIS SITUATION.
THE PACIFIC LOW WILL LIFT NORTHWARD OUT OF THE AREA ON SUNDAY AND
PROVIDE A REMAINING COOLER TREND. SOME SHOWERS SHOULD REMAIN ACROSS
THE NORTH BUT AMOUNTS SHOULD BE LIGHTER. SOME WEST/NORTHWEST BREEZES
ARE ANTICIPATED BUT NOT NEARLY AS STRONG COMPARED TO THE PREVIOUS
COUPLE OF DAYS. TEMPERATURES WILL REMAIN BELOW NORMAL. ALL THE
MODELS SEEM TO BE SHOWING THIS TREND.
MODELS CONTINUE TO BE IN ALIGNMENT FOR A DRIER AND WARMER EARLY NEXT
WEEK AS THE NEXT PACIFIC TROUGH DIGS INTO THE WEST COAST. BASED ON
THE LOW POSITION...EXPECTING A MORE PRONOUNCED DRYLINE TO DEVELOP
ACROSS THE EASTERN PLAINS AND SLOSH BACK AND FORTH DUE TO THE
TYPICAL DIURNAL TRENDS. GFS/ECMWF MODELS BOTH PAINT THE FIRST
DRYLINE THUNDERSTORM DEVELOPMENT AS EARLY AS TUESDAY AND CONTINUING
THROUGH THE END OF THE WEEK. TYPICALLY UNDER THESE SCENARIOS...A
CONCENTRATED LINE OF THUNDERSTORMS DEVELOPS AND PUSHES THE DRYLINE
FURTHER WEST THAN ANTICIPATED. WILL BE MONITORING THAT.
BOTTOMLINE...MUCH LOWER HUMIDITY AND WARMER TEMPS WOULD BE FOUND
WEST OF THE RIO GRANDE VALLEY WITH HIGHER RH AND MORE PRECIPITATION
POTENTIAL EAST OF THE VALLEY. BREEZINESS IS TYPICALLY FOUND ALONG
THE DRYLINE PASSAGE.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1028 PM EDT SAT MAY 9 2015
.SYNOPSIS...
THE WEATHER PATTERN OVER THE AREA...WHICH HAS BEEN WARM AND DRY...
FOR THE PAST SEVERAL DAY...IS ABOUT TO CHANGE. A SLOW MOVING COLD
FRONT WILL DROP OUT OF CANADA ON SUNDAY AND BRING SHOWERS AND A
FEW THUNDERSTORMS TO MUCH OF NORTHERN NEW YORK AND VERMONT. THIS
FRONT WILL BE SLOW TO CLEAR THE AREA...THUS THE THREAT FOR
ADDITIONAL SHOWERS WILL EXIST SUNDAY NIGHT THROUGH MONDAY NIGHT.
THE SHOWERS WILL BE FAIRLY WIDESPREAD DURING THIS TIME PERIOD.
ABOVE NORMAL TEMPERATURES ARE EXPECTED ON SUNDAY...BUT RETURN TO
NORMAL CONDITIONS ON MONDAY.
&&
.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
AS OF 1028 PM EDT SATURDAY...SMALL UPWARD ADJUSTMENTS TO
POPS/SHOWERS ACROSS THE NORTHERN TIER OF COUNTIES OVERNIGHT TO
ACCOUNT FOR CURRENT SCT ACTIVITY ADVANCING EAST FROM THE SLV
SOUTHWEST THROUGH LAKE ONTARIO INTO CENTRAL NY. BEST CHANCE OF
SEEING A SHOWER STILL ACROSS OUR NORTHERN NY COUNTIES HOWEVER.
BTV6 AND TO A LESSER EXTENT THE HRRR APPEAR TO BE CAPTURING
CURRENT CONVECTIVE TRENDS THE BEST AND HAVE LEANED TOWARD THEIR
IDEA ACCORDINGLY. STILL LOOKING AT ONLY 20/30 POPS IN THESE AREAS
HOWEVER WITH MANY FOLKS REMAINING DRY OVERNIGHT, ESPECIALLY
CENTRAL AND SOUTH. LOW TEMPERATURES STILL APPEAR REASONABLE, FROM
THE UPPER 50S TO MID 60S UNDER LIGHT TO MODERATE SOUTH BREEZES.
HAVE A GREAT NIGHT.
&&
.SHORT TERM /8 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 347 PM EDT SATURDAY...COLD FRONT WILL FINALLY MOVE DOWN
FROM CANADA DURING THE LATE MORNING AND AFTERNOON HOURS...BUT WILL
HAVE A HARD TO MOVING TOO FAR SOUTH. THE FRONT WILL BE A BETTER
FORCING MECHANISM THAN TODAY FOR SOME CONVECTION TO FORM ALONG IT.
DEEP LAYER SHEAR INCREASES OVER THE FRONT AND THIS SHOULD HELP TO
ORGANIZE THE CONVECTION A BIT...BUT LESS INSTABILITY WILL EXIST
THAN TODAY. FEEL SHOWERS WILL BECOME FAIRLY WIDESPREAD OVER THE
AREA DURING THE LATE MORNING AND AFTERNOON HOURS WITH A FEW
THUNDERSTORMS AS WELL. ABOVE NORMAL TEMPERATURES ARE EXPECTED WITH
HIGHS IN THE 70S TO AROUND 80. PATTERN GETS A BIT MESSY SUNDAY
NIGHT THROUGH MONDAY NIGHT. FRONTAL BOUNDARY WILL REMAIN JUST
SOUTH OF THE AREA SUNDAY NIGHT...THEN RETURN NORTH ON MONDAY AS AN
UPPER LEVEL TROUGH OF LOW PRESSURE MOVES OUT OF THE GREAT LAKES
REGION. INCREASING DYNAMIC SUPPORT WILL BE TAKING PLACE MONDAY AND
ESPECIALLY MONDAY NIGHT FOR SHOWERS TO BE FAIRLY WIDESPREAD ONCE
AGAIN...BUT PLENTY OF CLOUDS AND HIGHS ONLY IN 60S WILL LIMIT
INSTABILITY...SO HAVE HELD OFF ON THE MENTION OF THUNDERSTORMS
SUNDAY NIGHT THROUGH MONDAY. NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 307 PM EDT SATURDAY...EARLY TO MID NEXT WEEK STARTS OFF
UNSETTLED BUT BY LATE WEEK ANOTHER GREAT STRETCH OF WEATHER IS
UPON US.
SOME SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE PROGRESSING ACROSS
THE REGION TUESDAY MORNING BEFORE THE AREA BREAKS INTO THE DRY SLOT
DURING THE AFTERNOON HOURS. THIS WILL LEAD TO SOME BREAKS IN THE
CLOUDS...WARMING TEMPERATURES...AND DEVELOPING BREEZY WINDS AS
MIXING INCREASES WITH COLD AIR ADVECTION ENSUING. COULD ALSO SEE
SOME ADDITIONAL SCATTERED SHOWER/POSSIBLE THUNDERSTORM DEVELOPMENT
WITH SOME INSTABILITY...BUT NOT ANTICIPATED TO BE WIDESPREAD. HIGHS
SHOULD REACH WELL INTO THE 70S TO PERHAPS NEAR 80F. MORE POTENT SHOT
OF COOLER AIR AND NORTHWEST FLOW WILL MOVE INTO THE AREA FOR
WEDNESDAY BRINGING SOME BREEZY NORTHWEST WINDS...ADDITIONAL
CLOUDS...AND THE CHANCE FOR SOME SCATTERED SHOWERS. TEMPERATURES
WILL BE SIGNIFICANTLY COOLER WITH WEDNESDAY MORNING LOWS IN THE 40S
TO NEAR 50F AND AFTERNOON HIGHS STRUGGLING TO BREAK 60 DEGREES. BY
WEDNESDAY NIGHT HIGH PRESSURE BEGINS TO BUILD INTO THE REGION AND
PERSISTS THROUGH THE REMAINDER OF THE WEEK AND INTO AT LEAST THE
FIRST HALF OF THE WEEKEND. THIS WILL LEAD TO MOSTLY SUNNY
SKIES...COOL NIGHTS...AND WARMING DAYTIME TEMPERATURES. HIGHS IN THE
60S THURSDAY...60S/LOW 70S FRIDAY...AND WIDESPREAD 70S BY NEXT
SATURDAY. LOWS 28-42F WEDNESDAY/THURSDAY NIGHTS AND 37-47F FRIDAY
NIGHT.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...VFR
WILL PERSIST FOR MOST OF THE REGION THROUGH THE PERIOD...ALTHOUGH
SOME MVFR CONDITIONS AROUND RUT AND POSSIBLY MPV MAY DEVELOP
TONIGHT AND SUNDAY MORNING. OVERNIGHT...SOUTHERLY FLOW MAY BRING
IN A LOWER STRATUS DECK AND MVFR CEILINGS TO RUT AFTER 06Z WITH
BORDERLINE MVFR CONDITIONS AT MPV AROUND THE SAME TIME. SOME LOWER
CEILINGS WILL ALSO BE PROGRESSING EASTWARD FROM THE GREAT LAKES
ALONG AND AHEAD OF FRONTAL SYSTEM AND IS EXPECTED TO MOVE INTO
MSS/SLK SUNDAY EVENING. SHOWERS WILL ALSO BEGIN TO DEVELOP LATER
SUNDAY MORNING...WITH INCREASED ACTIVITY IN THE AFTERNOON AND
POSSIBLE THUNDERSTORMS ACROSS THE NORTH COUNTRY. LOWER
VISIBILITIES ARE POSSIBLE WITH SHOWERY ACTIVITY.
SURFACE WINDS WILL BE SOUTH/SOUTHWESTERLY FOR THE REMAINDER OF
TONIGHT FROM 5 TO 10 KNOTS WITH GUSTS TO 20 KNOTS POSSIBLE AT
BTV. LOOK FOR WINDS 5-15 KNOTS OUT OF THE SOUTH/SOUTHWEST SUNDAY
MORNING.
OUTLOOK 00Z MONDAY THROUGH THURSDAY...
00Z MONDAY THROUGH 00Z THURSDAY..VFR WITH PERIODS OF MVFR IN RAIN
SHOWERS AND POSSIBLE THUNDERSTORMS AS A FRONTAL SYSTEM GRADUALLY
MOVES ACROSS THE REGION.
00Z THURSDAY ONWARD...VFR UNDER BUILDING HIGH PRESSURE.
&&
.MARINE...
SOUTH WINDS OF 15 TO 25 KNOTS WILL PERSIST TONIGHT AND THUS A LAKE
WIND ADVISORY REMAINS IN EFFECT. WAVES WILL BE 2 TO 3 FEET...
ESPECIALLY OVER THE NORTHERN HALF OF THE LAKE...MAKING FOR CHOPPY
CONDITIONS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...EVENSON
NEAR TERM...JMG
SHORT TERM...EVENSON
LONG TERM...MUCCILLI
AVIATION...JMG/MV
MARINE...EVENSON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
937 PM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 926 PM CDT SAT MAY 9 2015
JUST GETTING A LOOK AT LATEST NAM IN THROUGH 36 HOURS. NOT SEEING
SNOW YET WHERE NAM H850 TEMPS ARE MARGINALLY CLOSE TO SNOW TYPE
ACROSS NORTHWEST SD AND SOUTHWEST ND. LOWER BOUNDARY LAYER TEMPS
STILL TOO WARM AS OF YET. DO THINK THERE WILL BE A CHANGE OVER TO
SNOW AFTER MIDNIGHT SOUTHWEST WHERE H850 TEMP IS CLOSE TO -3 C ON
NAM. STILL A LOT OF UNCERTAINTY OUTSIDE OF THE SOUTHWEST. WILL LET
THE WINTER STORM WATCH BEGIN AT 06Z AS PLANNED NORTH OF WARNING
AREA AND AFTER 12Z NORTH AND EAST OF MISSOURI RIVER.
UPDATE ISSUED AT 701 PM CDT SAT MAY 9 2015
THIS UPDATE WILL MAINLY CONCERN CLOUDS AND WINDS AS PRECIP JUST
MOVING INTO THE REGION AT THIS TIME. WITH A NORTHEAST WIND SOME
EVAPORATION OCCURRING BELOW CLOUD BASE WHICH WILL EVENTUALLY
SATURATE THE LAYERS TONIGHT. UPDATED CURRENT TEMPS...WINDS...AND
CLOUDS. WILL WAIT FOR A NEW RUNS LATER THIS EVENING OF SOME SHORT
RANGE MODELS HRRR FOR FURTHER REFINEMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
IMPENDING WINTER STORM DOMINATES THE FORECAST HIGHLIGHTS IN THE
SHORT TERM PERIOD. 12Z MODELS IN DECENT AGREEMENT WITH MAIN
FEATURES.
CURRENTLY...DEEP LOW PRESSURE SWINGING EAST ACROSS THE CENTRAL
ROCKIES...WHICH WILL LIFT NORTHEAST INTO THE HIGH PLAINS TONIGHT.
SFC RIDGE OF HIGH PRESSURE STRETCHING FROM LAKE WINNIPEG SOUTHWEST
THROUGH NORTHEASTERN NORTH DAKOTA INTO SOUTHWESTERN ND. EMBEDDED
S/WV IMPULSES CONTINUE TO LIFT NORTH OUT OF THE UPPER LOW ACROSS
THE DAKOTAS...TRIGGERING PRECIPITATION MAINLY ON THE SOUTHERN EDGE
AND ALONG TO EAST OF THE SFC RIDGE AXIS. CLEAR TO PARTLY CLOUDY
ACROSS MY NORTH WITH STRONGER SUBSIDENCE NEAR THE SFC RIDGE.
PRECIPITATION MAINLY IN THE FORM OF RAIN WILL CONTINUE TO DEVELOP
ACROSS MY FAR SOUTH AND SOUTHEASTERN QUARTER NOW INTO THIS
EVENING WHILE DRIER CONDITIONS LINGER WEST AND NORTH. SFC RIDGE
WASHES OUT/LIFTS NORTH THIS EVENING INTO THE OVERNIGHT WITH A SFC
TROUGH DEVELOPING ACROSS EASTERN SOUTH DAKOTA INTO THE JAMES RIVER
BASIN. PRECIPITATION BAND DEVELOPS IN EARNEST ACROSS SOUTH DAKOTA
OVERNIGHT...LIFTING NORTH ACROSS SOUTHWEST AND CENTRAL NORTH
DAKOTA LATE TONIGHT INTO SUNDAY AS THE UPPER LOW LUMBERS NORTH
INTO SOUTH DAKOTA. INHERITED POP GRIDS LOOKED GOOD SO ONLY SOME
MINOR TWEAKS WERE MADE.
SIGNIFICANT SNOWFALL LIKELY WHERE CURRENT WINTER STORM WARNINGS
ARE IN EFFECT. THERMAL PROFILES ARE MORE SUPPORTIVE OF ALL SNOW OR
MAINLY SNOW WEST OF THE MISSOURI RIVER AND ALONG AND SOUTH OF
INTERSTATE 94 WHERE THERE IS VERY NICE MODEL AGREEMENT ON COOLING
925/850MB TEMPS DUE IN PART TO DYNAMIC COOLING AND ALSO MID LEVEL
CAA. STILL LINGERING UNCERTAINTY NORTH AND EAST OF THIS AREA WHERE
TEMPS ALOFT ARE SLIGHTLY WARMER AND THE BIG QUESTION IS EVENTUAL
SFC TEMPERATURES TONIGHT INTO SUNDAY. 2-3 DEGREES WILL HAVE
SIGNIFICANT IMPACTS TO PRECIP TYPE FOR THIS AREA...AND THUS SNOW
ACCUMULATIONS. FOR EXAMPLE...I RAN TWO SCENARIOS FOR BISMARCK ON
TONIGHT THROUGH SUNDAY. THE FIRST WAS A MORE AVERAGE SOLUTION FOR
TEMPERATURES WHERE I GOT 1-3 INCHES OF WET SNOW THROUGH SUNDAY
AFTERNOON (THIS WAS UTILIZED FOR THIS FORECAST PACKAGE). THE
SECOND SCENARIO WAS 2 DEGREES COOLER...WHICH RESULTED IN 6-9
INCHES (THIS WAS NOT USED). OPTED TO UPGRADE MORTON COUNTY TO A
WINTER STORM WARNING BASED ON FORECAST TEMPS ALOFT (AS DISCUSSED
ABOVE). WILL KEEP THE REMAINDER OF THE WATCH AS IS THROUGH SUNDAY
DUE TO THE LINGERING UNCERTAINTY (SEE LONG TERM BELOW FOR WATCH
EXTENSION DISCUSSION).
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
A STRONG SPRING STORM WILL LINGER THROUGH MONDAY EVENING. THIS
WILL BE THE MAIN FOCUS FOR THE LONG TERM FORECAST.
THE 12 UTC MODELS ARE IN FAIRLY GOOD AGREEMENT WITH RESPECT TO
TIMING AND LOCATION OF THE HEAVIEST PRECIPITATION AND EVOLUTION OF
THE STORM SUNDAY INTO MONDAY. THE 12 UTC GEM AND NAM APPEAR TO BE
ON THE FRINGES WITH THE FORMER LIKELY TOO WET AND TOO FAR TO THE
WEST AND THE LATER TO DRY AND TOO FAR TO THE EAST. FOR THIS
FORECAST UTILIZED A BLEND OF THE GFS/ECMWF/SREF.
THE WINTER STORM WATCH HAS BEEN EXPANDED A LITTLE FURTHER TO THE
EAST AS THERE IS AN INCREASED POTENTIAL FOR ACCUMULATING SNOW
ACROSS PORTIONS OF THE JAMES RIVER VALLEY.
SUNDAY EVENING AND OVERNIGHT...MODERATE TO HEAVY PRECIPITATION IS
EXPECTED TO SPREAD EAST OF THE MISSOURI RIVER AND ALONG I-94 AS A
DEEP SURFACE LOW PROPAGATES ACROSS THE EASTERN DAKOTAS. A
TROWL...COUPLED WITH STRONG FRONTOGENETIC FORCING WILL LIKELY
PRODUCE HEAVY BANDS OF RAIN/SNOW. AS MUCH AS THREE INCHES OF
LIQUID IS POSSIBLE EAST OF THE MISSOURI RIVER AND ALONG/SOUTH OF
I-94. THE 12 UTC RUNS CONTINUE TO INDICATE H85 TEMPERATURES AROUND
-2C TO -3C AND SURFACE TEMPERATURES HOVERING NEAR FREEZING. THIS
IN TURN COULD LEAD TO ACCUMULATIONS OF HEAVY WET SNOW. AS SUCH
ISSUED A WATCH FOR PORTIONS OF THE JAMES RIVER VALLEY.
HOWEVER...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
PRECIPITATION TYPE AS A FEW DEGREES DIFFERENCE IN SURFACE
TEMPERATURE COULD MEAN THE DIFFERENCE BETWEEN NO SNOW AND 6+
INCHES. IN ADDITION TO HEAVY PRECIPITATION...THIS POTENT STORM
WILL ALSO PRODUCE STRONG WINDS. AS THE LOW WRAPS UP ACROSS THE
EASTERN DAKOTAS...THE PRESSURE GRADIENT WILL STEEPEN. WINDS AROUND
35 MPH WILL BE LIKELY SUNDAY AND MONDAY. DUE TO THE TIMING (RATHER
LATE IN THE SEASON FOR SNOW) AND POTENTIAL IMPACTS FELT IT WAS
NECESSARY TO ISSUE A WATCH AND GIVE A HEADS UP...BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO WARRANT A MAJOR ALERT.
PRECIPITATION WILL CONTINUE ACROSS MAINLY CENTRAL AND EASTERN
PORTIONS OF NORTH DAKOTA THROUGH MONDAY. NORTHWEST NORTH DAKOTA
MAY GET LEFT HIGH AND DRY. TEMPERATURES ACROSS THE SOUTH AND EAST
WILL STRUGGLE TO GET OUT OF THE 30S AND 40S OVER THE NEXT SEVERAL
DAYS...WHILE THE NORTHWEST MAY REACH THE 50S AND 60S.
THERE WILL BE ADDITIONAL CHANCES FOR RAIN
WEDNESDAY/THURSDAY...WITH A WARM UP EXPECTED LATE WEEK INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 926 PM CDT SAT MAY 9 2015
SIGNIFICANT SPRING SNOW STORM WILL IMPACT SOUTHERN NORTH DAKOTA
BEGINNING TONIGHT. CURRENT CONDITIONS AT 9 PM CDT SATURDAY
EVENING REMAIN VFR ALL TAF SITES BUT KJMS WHERE RAIN HAS BEGUN.
KDIK-KBIS WILL SEE DETERIORATING CONDITIONS TO IFR IN CLOUDS AND
RAIN/SNOW AFTER 10Z OR 5 AM TONIGHT. CONDITIONS CONTINUE THROUGH
SUNDAY. KISN WILL REMAIN VFR. LOOK FOR RAIN MOVING INTO KMOT
SUNDAY AFTERNOON WITH MVFR EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM 1 AM CDT /MIDNIGHT MDT/ SUNDAY THROUGH
MONDAY MORNING FOR NDZ020-033-040.
WINTER STORM WARNING FROM 1 AM CDT /MIDNIGHT MDT/ SUNDAY TO 7 AM
CDT /6 AM MDT/ MONDAY FOR NDZ034-041>045.
WINTER STORM WATCH FROM 7 AM CDT SUNDAY THROUGH MONDAY EVENING
FOR NDZ022-023-035>037-046-047.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...AJ
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
710 PM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 701 PM CDT SAT MAY 9 2015
THIS UPDATE WILL MAINLY CONCERN CLOUDS AND WINDS AS PRECIP JUST
MOVING INTO THE REGION AT THIS TIME. WITH A NORTHEAST WIND SOME
EVAPORATION OCCURRING BELOW CLOUD BASE WHICH WILL EVENTUALLY
SATURATE THE LAYERS TONIGHT. UPDATED CURRENT TEMPS...WINDS...AND
CLOUDS. WILL WAIT FOR A NEW RUNS LATER THIS EVENING OF SOME SHORT
RANGE MODELS HRRR FOR FURTHER REFINEMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
IMPENDING WINTER STORM DOMINATES THE FORECAST HIGHLIGHTS IN THE
SHORT TERM PERIOD. 12Z MODELS IN DECENT AGREEMENT WITH MAIN
FEATURES.
CURRENTLY...DEEP LOW PRESSURE SWINGING EAST ACROSS THE CENTRAL
ROCKIES...WHICH WILL LIFT NORTHEAST INTO THE HIGH PLAINS TONIGHT.
SFC RIDGE OF HIGH PRESSURE STRETCHING FROM LAKE WINNIPEG SOUTHWEST
THROUGH NORTHEASTERN NORTH DAKOTA INTO SOUTHWESTERN ND. EMBEDDED
S/WV IMPULSES CONTINUE TO LIFT NORTH OUT OF THE UPPER LOW ACROSS
THE DAKOTAS...TRIGGERING PRECIPITATION MAINLY ON THE SOUTHERN EDGE
AND ALONG TO EAST OF THE SFC RIDGE AXIS. CLEAR TO PARTLY CLOUDY
ACROSS MY NORTH WITH STRONGER SUBSIDENCE NEAR THE SFC RIDGE.
PRECIPITATION MAINLY IN THE FORM OF RAIN WILL CONTINUE TO DEVELOP
ACROSS MY FAR SOUTH AND SOUTHEASTERN QUARTER NOW INTO THIS
EVENING WHILE DRIER CONDITIONS LINGER WEST AND NORTH. SFC RIDGE
WASHES OUT/LIFTS NORTH THIS EVENING INTO THE OVERNIGHT WITH A SFC
TROUGH DEVELOPING ACROSS EASTERN SOUTH DAKOTA INTO THE JAMES RIVER
BASIN. PRECIPITATION BAND DEVELOPS IN EARNEST ACROSS SOUTH DAKOTA
OVERNIGHT...LIFTING NORTH ACROSS SOUTHWEST AND CENTRAL NORTH
DAKOTA LATE TONIGHT INTO SUNDAY AS THE UPPER LOW LUMBERS NORTH
INTO SOUTH DAKOTA. INHERITED POP GRIDS LOOKED GOOD SO ONLY SOME
MINOR TWEAKS WERE MADE.
SIGNIFICANT SNOWFALL LIKELY WHERE CURRENT WINTER STORM WARNINGS
ARE IN EFFECT. THERMAL PROFILES ARE MORE SUPPORTIVE OF ALL SNOW OR
MAINLY SNOW WEST OF THE MISSOURI RIVER AND ALONG AND SOUTH OF
INTERSTATE 94 WHERE THERE IS VERY NICE MODEL AGREEMENT ON COOLING
925/850MB TEMPS DUE IN PART TO DYNAMIC COOLING AND ALSO MID LEVEL
CAA. STILL LINGERING UNCERTAINTY NORTH AND EAST OF THIS AREA WHERE
TEMPS ALOFT ARE SLIGHTLY WARMER AND THE BIG QUESTION IS EVENTUAL
SFC TEMPERATURES TONIGHT INTO SUNDAY. 2-3 DEGREES WILL HAVE
SIGNIFICANT IMPACTS TO PRECIP TYPE FOR THIS AREA...AND THUS SNOW
ACCUMULATIONS. FOR EXAMPLE...I RAN TWO SCENARIOS FOR BISMARCK ON
TONIGHT THROUGH SUNDAY. THE FIRST WAS A MORE AVERAGE SOLUTION FOR
TEMPERATURES WHERE I GOT 1-3 INCHES OF WET SNOW THROUGH SUNDAY
AFTERNOON (THIS WAS UTILIZED FOR THIS FORECAST PACKAGE). THE
SECOND SCENARIO WAS 2 DEGREES COOLER...WHICH RESULTED IN 6-9
INCHES (THIS WAS NOT USED). OPTED TO UPGRADE MORTON COUNTY TO A
WINTER STORM WARNING BASED ON FORECAST TEMPS ALOFT (AS DISCUSSED
ABOVE). WILL KEEP THE REMAINDER OF THE WATCH AS IS THROUGH SUNDAY
DUE TO THE LINGERING UNCERTAINTY (SEE LONG TERM BELOW FOR WATCH
EXTENSION DISCUSSION).
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
A STRONG SPRING STORM WILL LINGER THROUGH MONDAY EVENING. THIS
WILL BE THE MAIN FOCUS FOR THE LONG TERM FORECAST.
THE 12 UTC MODELS ARE IN FAIRLY GOOD AGREEMENT WITH RESPECT TO
TIMING AND LOCATION OF THE HEAVIEST PRECIPITATION AND EVOLUTION OF
THE STORM SUNDAY INTO MONDAY. THE 12 UTC GEM AND NAM APPEAR TO BE
ON THE FRINGES WITH THE FORMER LIKELY TOO WET AND TOO FAR TO THE
WEST AND THE LATER TO DRY AND TOO FAR TO THE EAST. FOR THIS
FORECAST UTILIZED A BLEND OF THE GFS/ECMWF/SREF.
THE WINTER STORM WATCH HAS BEEN EXPANDED A LITTLE FURTHER TO THE
EAST AS THERE IS AN INCREASED POTENTIAL FOR ACCUMULATING SNOW
ACROSS PORTIONS OF THE JAMES RIVER VALLEY.
SUNDAY EVENING AND OVERNIGHT...MODERATE TO HEAVY PRECIPITATION IS
EXPECTED TO SPREAD EAST OF THE MISSOURI RIVER AND ALONG I-94 AS A
DEEP SURFACE LOW PROPAGATES ACROSS THE EASTERN DAKOTAS. A
TROWL...COUPLED WITH STRONG FRONTOGENETIC FORCING WILL LIKELY
PRODUCE HEAVY BANDS OF RAIN/SNOW. AS MUCH AS THREE INCHES OF
LIQUID IS POSSIBLE EAST OF THE MISSOURI RIVER AND ALONG/SOUTH OF
I-94. THE 12 UTC RUNS CONTINUE TO INDICATE H85 TEMPERATURES AROUND
-2C TO -3C AND SURFACE TEMPERATURES HOVERING NEAR FREEZING. THIS
IN TURN COULD LEAD TO ACCUMULATIONS OF HEAVY WET SNOW. AS SUCH
ISSUED A WATCH FOR PORTIONS OF THE JAMES RIVER VALLEY.
HOWEVER...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
PRECIPITATION TYPE AS A FEW DEGREES DIFFERENCE IN SURFACE
TEMPERATURE COULD MEAN THE DIFFERENCE BETWEEN NO SNOW AND 6+
INCHES. IN ADDITION TO HEAVY PRECIPITATION...THIS POTENT STORM
WILL ALSO PRODUCE STRONG WINDS. AS THE LOW WRAPS UP ACROSS THE
EASTERN DAKOTAS...THE PRESSURE GRADIENT WILL STEEPEN. WINDS AROUND
35 MPH WILL BE LIKELY SUNDAY AND MONDAY. DUE TO THE TIMING (RATHER
LATE IN THE SEASON FOR SNOW) AND POTENTIAL IMPACTS FELT IT WAS
NECESSARY TO ISSUE A WATCH AND GIVE A HEADS UP...BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO WARRANT A MAJOR ALERT.
PRECIPITATION WILL CONTINUE ACROSS MAINLY CENTRAL AND EASTERN
PORTIONS OF NORTH DAKOTA THROUGH MONDAY. NORTHWEST NORTH DAKOTA
MAY GET LEFT HIGH AND DRY. TEMPERATURES ACROSS THE SOUTH AND EAST
WILL STRUGGLE TO GET OUT OF THE 30S AND 40S OVER THE NEXT SEVERAL
DAYS...WHILE THE NORTHWEST MAY REACH THE 50S AND 60S.
THERE WILL BE ADDITIONAL CHANCES FOR RAIN
WEDNESDAY/THURSDAY...WITH A WARM UP EXPECTED LATE WEEK INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 701 PM CDT SAT MAY 9 2015
SIGNIFICANT SPRING SNOW STORM WILL IMPACT SOUTHERN NORTH DAKOTA
BEGINNING TONIGHT. CURRENT VFR CONDITIONS AT 7 PM CDT SATURDAY
EVENING REMAIN VFR ACROSS THE STATE. HOWEVER....KDIK-KBIS-KJMS
WILL SEE A DETERIORATING TO IFR IN CLOUDS AND RAIN/SNOW AFTER 10Z
OR 5 AM TONIGHT. CONDITIONS CONTINUE THROUGH SUNDAY. KISN WILL
REMAIN VFR. LOOK FOR RAIN MOVING INTO KMOT SUNDAY AFTERNOON WITH
MVFR EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM 1 AM CDT /MIDNIGHT MDT/ SUNDAY THROUGH
MONDAY MORNING FOR NDZ020-033-040.
WINTER STORM WARNING FROM 1 AM CDT /MIDNIGHT MDT/ SUNDAY TO 7 AM
CDT /6 AM MDT/ MONDAY FOR NDZ034-041>045.
WINTER STORM WATCH FROM 7 AM CDT SUNDAY THROUGH MONDAY EVENING
FOR NDZ022-023-035>037-046-047.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...AJ
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
114 PM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 114 PM CDT FRI MAY 8 2015
SKY COVER WAS INCREASED WITH A LARGE AREA OF MVFR-LOW VFR STRATUS
FROM THE NORTHWEST CORNER SOUTH-SOUTHEAST ALONG THE MISSOURI RIVER
AND POINTS EAST. HRRR HANDLES THIS THE BEST AND WAS UTILIZED FOR
SKY GRIDS THIS MORNING AND AFTERNOON.
MAIN STORY WILL BE POTENTIAL STORM SET TO ARRIVE TOMORROW.
PRELIMINARY ANALYSIS OF 12Z MODELS SHOWS A SLIGHT SOUTHWARD SHIFT
WITH THE PRECIPITATION BAND. WILL CONTINUE TO MONITOR. SPS WAS
UPDATED A FEW HOURS AGO.
UPDATE
ISSUED AT 909 AM CDT FRI MAY 8 2015
INHERITED FORECAST LOOKING GOOD. ALLOWED THE FROST ADVISORY TO
EXPIRE EARLIER WITH TEMPERATURES ON THE INCREASE. OTHERWISE PARTLY
SUNNY AND DRY TODAY WITH HIGHS IN THE 50S. PRECIPITATION STARTS TO
DEVELOP ACROSS THE SOUTHWEST TONIGHT. MAY SEE A FEW LIGHT SHOWERS
WEST THIS AFTERNOON...HUNDRETH AT BEST BUT MORE LIKELY TRACE
AMOUNTS.
UPDATE ISSUED AT 616 AM CDT FRI MAY 8 2015
FORECAST REMAINS ON TRACK. LATEST HOURLY TEMPS DROPPED A DEGREE OR
TWO MOST LOCATIONS...NEAR 30 NORTH AND LOW/MID 30S ELSEWHERE.
FROST ADVISORY WILL CONTINUE UNTIL 8 AM CDT. NO CHANGES MADE OTHER
THAN BLENDING TO LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN HIGHLIGHT IN THE NEAR TERM PERIOD IS THE ONGOING FROST
ADVISORY. CLOUDS VARYING BETWEEN PARTLY CLOUDY AND MOSTLY CLOUDY
IN THE ADVISORY AREA. THE COLDEST TEMPERATURES ARE RESIDING IN THE
NORTHWEST WITH MID 30S WHICH IS LIKELY RESULTING IN AREAS OF
FROST. WILL LET THE ADVISORY CONTINUE THROUGH AT LEAST THE NEXT
UPDATE CYCLE. WILL STILL MENTION AN ISOLATED SHOWER THROUGH 12Z
IN THE EAST CENTRAL ZONES AS A WEAK SHORTWAVE TRANSITIONS INTO
THIS AREA. THE HRRR AND NMM WEST STILL SHOW A THREAT FOR THIS.
FOR THE REST OF THE SHORT TERM PERIOD...MAIN HIGHLIGHTS WILL BE
INCREASING CHANCES OF PRECIPITATION/RAIN SHOWERS ACROSS SOUTHWEST
AND INTO SOUTH CENTRAL NORTH DAKOTA FRIDAY NIGHT. IN ADDITION
AREAS OF FROST WILL ONCE AGAIN BE POSSIBLE ESPECIALLY OUTSIDE OF
THE PRECIPITATION AREAS MENTIONED ABOVE.
THE LATEST WATER VAPOR IMAGERY SHOWS A CLOSED UPPER LOW OVER
CENTRAL/SOUTHERN CALIFORNIA WITH A DEFORMATION ZONE INTO IDAHO.
FURTHER DOWNSTREAM INTO NORTH DAKOTA...A CONSOLIDATED SOUTHWEST
FLOW WITH A COUPLE OF WEAK SHORTWAVES SHIFTING THROUGH GENERATING
MID LEVEL CLOUDS. EXPECTING A DRY DAY TODAY WITH PARTLY TO MOSTLY
CLOUDY CONDITIONS. FOR FRIDAY NIGHT...A COUPLE OF SHORTWAVES
PEELING OFF THE UPPER LOW MOVE INTO SOUTHWEST NORTH DAKOTA. THE
AFOREMENTIONED DEFORMATION ZONE SLIDES INTO SOUTHWEST/SOUTH
CENTRAL NORTH DAKOTA AFTER 06Z SATURDAY. WITH THE DEFORMATION
ZONE/POOLING OF MOISTURE IN PLACE...INCREASED VERTICAL MOTION OVER
THIS AREA PER 850-300MB OMEGA FIELD/DIFFERENTIAL POSITIVE
VORTICITY ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT.
VERTICAL MOTION WILL ALSO BE ENHANCED BY THE RIGHT ENTRANCE REGION
OF A 90KT/300MB JET STREAK EXTENDING FROM SOUTHERN MANITOBA INTO
SOUTHEAST SASKATCHEWAN AND NORTHWEST NORTH DAKOTA. THE RESULT WILL
BE FOR SHOWERS IN THE SOUTHWEST AND CHANCE OF SHOWERS EXTENDING
INTO SOUTH CENTRAL NORTH DAKOTA THROUGH 12Z SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN FORECAST CONCERN INVOLVES DEEP STORM SYSTEM SLOWLY LIFTING
FROM 4 CORNERS REGION SATURDAY MORNING TO SOUTH DAKOTA BY 00Z
MONDAY. 00Z DETERMINISTIC MODELS HAVE SHIFTED FARTHER NORTH WITH
SYSTEM WITH PORTIONS OF SOUTH CENTRAL ND NOW LOOKING AT POSSIBLE
ACCUMULATING SNOW...MAINLY ON SUNDAY. NAM REMAINS A BIT OF AN
OUTLIER...NOT AS FAR NORTH WITH QPF...THOUGH GFS/NAM/SREF ARE IN
DECENT AGREEMENT. GFS DEPICTS 850MB TEMPS AROUND -2C FROM
SOUTHWEST THROUGH EAST-CENTRAL ND BY 18Z SUNDAY COINCIDENT WITH
BROAD AREA OF STRONG 700MB FRONTOGENESIS AND ISENTROPIC LIFT. WPC
WINTER WEATHER DESK DEPICTS AREA OF 6 INCHES PLUS ACROSS EXTREME
SOUTHWEST FOR DAY 3 /SUNDAY/ WITH THE MAIN BULLSEYE FOR HEAVIEST
SNOW ACCUMULATIONS ACROSS NORTHWESTERN SOUTH DAKOTA. SURFACE TEMPS
NEAR/ABOVE FREEZING MAY LIMIT ACCUMULATIONS. NO HEADLINES PLANNED
AT THIS TIME THOUGH THEY MAY BE NEEDED IF MODELS MAINTAIN
CONSISTENCY WITH FUTURE RUNS. FOR NOW WILL ISSUE SPS TO HIGHLIGHT
POTENTIAL STORM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 114 PM CDT FRI MAY 8 2015
LARGE AREA OF MVFR-LOW VFR CIGS DRAPED ACROSS CENTRAL AND PORTIONS
OF EASTERN NORTH DAKOTA. WESTERN AND EASTERN EDGES OF THIS STRATUS
WILL SLOWLY ERODE WITH TIME THIS AFTERNOON INTO EARLY THIS
EVENING. -SHRA ARRIVE AT KDIK FROM 06Z- 12Z SATURDAY. SHOWERS IN
THE VICINITY AT KBIS BETWEEN BY 10Z SATURDAY. OTHER TERMINALS
SHOULD REMAIN DRY THROUGH THE 18Z PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...KS
LONG TERM...JNS
AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1246 PM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 1240 PM CDT FRI MAY 8 2015
TEMPS ARE STILL HAVING A HARD TIME WARMING MUCH AT ALL...WITH
AREAS STILL IN THE UPPER 30S. THEREFORE...WE WILL LOWER TEMPS A
FEW MORE DEGREES. THE HRRR CONTINUES TO INDICATE CLOUDS WILL BREAK
UP SOME LATER THIS AFTERNOON...AND TEMPS SHOULD RECOVER SOME.
OTHERWISE...NO OTHER CHANGES NEEDED THIS AFTERNOON FOR THE UPDATE.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI MAY 8 2015
FORECAST CHALLENGE CONCERNS TEMPERATURES...FROST POTENTIAL TONIGHT
AND LATE WEEKEND RAIN POTENTIAL. MODELS OVERALL IN PRETTY GOOD
AGREEMENT INTO THE START OF THE LONG RANGE. NAM LOOKS TO BE THE
QUICKEST IN EJECTING SURFACE LOW NE IN LATER PERIODS AND LOOKS TO
BE AN OUTLIER. OTHERWISE NO REAL MODEL PREFERENCE AND WILL USE
GFS/ECMWF BLEND.
SURFACE RIDGING TO BUILD INTO THE FA TODAY ACCOMPANIED BY AN
UNSEASONABLY COOL AIR MASS. WINDS/CLOUDS HAVE HELD TEMPERATURES UP
OVERNIGHT BUT WITH SOME DEGREE OF CLOUD COVER TODAY AND COOL
AIRMASS MAXIMUM TEMPERATURES LIKELY TO RUN A GOOD 10 DEGREES
COOLER THAN NORMAL.
THERE IS POTENTIAL FOR FROST...ESPECIALLY ACROSS THE NORTH
TONIGHT. DEGREE OF CLOUD COVER AND MIXING OVERNIGHT WILL DETERMINE
IF OR HOW WIDESPREAD FROST WILL BE. AT THIS POINT NOT ENOUGH
CONFIDENCE FOR ANY HEADLINES. AT ANY RATE EXPECT MINIMUM TEMPERATURES IN
THE 30S ACROSS THE REGION.
UPPER LOW OVER THE 4 CORNERS AREAS WILL BEGIN TO LIFT NE ON
SATURDAY. ASSOCIATED SURFACE LOW WILL DEEPEN OVER THE CENTRAL HIGH
PLAINS. MODELS ARE BRINGING IN SOME PCPN TO THE SOUTHERN HALF OF
THE FA HOWEVER TIME SECTIONS INDICATING MOISTURE LIMITED TO THE
MID/UPPER LEVELS AND LITTLE IN THE WAY OF ISENTROPIC LIFT OR LOWERING
CONDENSATION PRESSURE DEFICITS SO WILL KEEP FORECAST DRY. COLUMN
STILL PRETTY COOL SO BLO AVERAGE TEMPERATURES TO CONTINUE. WARMEST
READINGS WILL BE ACROSS THE SE FA WHERE WARM ADVECTION STRONGER.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI MAY 8 2015
LOW BECOMES STACKED OVER E CO BY SATURDAY NIGHT AND BEGINS TO
LIFT NE INTO THE CENTRAL PLAINS BY MORNING. BASED ON GOOD MODEL
AGREEMENT NUDGED POPS SLIGHTLY NORTH ACROSS THE SOUTH HALF OF THE
FA.
LOW LIFTS NE TO THE NE/SD/IA/MN BORDER AREA BY SUNDAY EVENING.
MODELS CONSISTENT IN LIFTING NORTHERN EDGE OF PCPN SHIELD TO THE
INTERNATIONAL BORDER WITH LARGE AREA OF LOW CONDENSATION PRESSURE
DEFICITS AND ISENTROPIC LIFT. CONFIDENCE INCREASING ON RESPECTABLE
RAIN EVENT AT LEAST FOR THE SE HALF OF THE FA.
MAINTAINED HIGH END POPS ACROSS THE SE HALF SUNDAY NIGHT HOWEVER
IF TRENDS CONTINUE MAY HAVE TO EXPAND HIGHER POPS FARTHER NORTH
AND WEST. STILL SOME SURFACE LOW TRACK DIFFERENCES SO WILL STAY
CONSERVATIVE FOR NOW. TEMPERATURES TO REMAIN BLO AVERAGE
SPLIT FLOW CONTINUES ACROSS NORTH AMERICA. LONG WAVE UPPER LEVEL
RIDGE OVER BC REMAINS OVER WESTERN CANADA. LONG WAVE TROUGH NEAR OR
EAST OF HUDSON BAY WILL SHIFT OFF THE EAST COAST OF CANADA THIS
PERIOD. IN THE SOUTHERN STREAM...LONG WAVE TROUGH REMAINS OVER THE
WEST COAST AS SHORT WAVES MOVE THROUGH THE FLOW. OVER THE NORTHERN
PLAINS...A LONG WAVE RIDGE BUILDS OVER THE AREA THROUGH THE PERIOD.
GFS AND ECMWF ARE IN REASONABLE AGREEMENT AT 84 HOURS. MODELS BECOME
180 DEGREES OUT OF PHASE BY 144 HOURS. THE ECMWF HAS BEEN TRENDING
FARTHER NORTHWEST WHILE THE GFS HAS BEEN TRENDING SOUTHWARD OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF WITH PROGRESSIVE SHORT WAVES
MOVING THROUGH THE SOUTHERN STREAM.
KEPT POPS FROM YESTERDAYS RUN FOR MON.
HIGH TEMPS DECREASED ZERO TO THREE DEGREES FOR MON AND WED.
ESSENTIALLY NO CHANGE TUE OR THU FRO YESTERDAYS FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM CDT FRI MAY 8 2015
CIGS WILL BE THE AVIATION CONCERN FOR THE REMAINDER OF TODAY AND
OVERNIGHT TONIGHT. THERE IS A HOLE DEVELOPING OVER WEST CENTRAL MN
THAT MAY EXPAND INTO THE FAR REGION AND WILL LIKELY HELP CLEAR OUT
BJI/TVF/GFK IN THE EARLY EVENING. ALTHOUGH I AM HESITANT TO GO CLEAR
IN THE OVERNIGHT HOURS...THE LATEST VIS IMAGERY IS GIVING SOME HOPE
THE MODELS MAY ACTUALLY BE RIGHT. WILL TEMPO GROUP SOME CLEARING IN
THE LATE AFTN AND EVENING...THEN SCT SKIES OVERNIGHT FOR THE VALLEY
AND MN SITES. FOR DVL...MUCH LESS CONFIDENCE AS IT IS FAR FROM THE
DEVELOPING HOLE AND WINDS WILL SHIFT NE...WHERE MOST OF SRN CANADA
IS OVC. CLEARING HAS PASSED REGINA BUT DON/T BELIEVE IT WILL BE TO
INTL BORDER BEFORE SUNSET AND HELP CLEAR US OUT OVERNIGHT. KEPT IT
MVFR THROUGH TOMORROW MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...HOPPES/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
909 AM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 909 AM CDT FRI MAY 8 2015
INHERITED FORECAST LOOKING GOOD. ALLOWED THE FROST ADVISORY TO
EXPIRE EARLIER WITH TEMPERATURES ON THE INCREASE. OTHERWISE PARTLY
SUNNY AND DRY TODAY WITH HIGHS IN THE 50S. PRECIPITATION STARTS TO
DEVELOP ACROSS THE SOUTHWEST TONIGHT. MAY SEE A FEW LIGHT SHOWERS
WEST THIS AFTERNOON...HUNDRETH AT BEST BUT MORE LIKELY TRACE
AMOUNTS.
UPDATE ISSUED AT 616 AM CDT FRI MAY 8 2015
FORECAST REMAINS ON TRACK. LATEST HOURLY TEMPS DROPPED A DEGREE OR
TWO MOST LOCATIONS...NEAR 30 NORTH AND LOW/MID 30S ELSEWHERE.
FROST ADVISORY WILL CONTINUE UNTIL 8 AM CDT. NO CHANGES MADE OTHER
THAN BLENDING TO LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN HIGHLIGHT IN THE NEAR TERM PERIOD IS THE ONGOING FROST
ADVISORY. CLOUDS VARYING BETWEEN PARTLY CLOUDY AND MOSTLY CLOUDY
IN THE ADVISORY AREA. THE COLDEST TEMPERATURES ARE RESIDING IN THE
NORTHWEST WITH MID 30S WHICH IS LIKELY RESULTING IN AREAS OF
FROST. WILL LET THE ADVISORY CONTINUE THROUGH AT LEAST THE NEXT
UPDATE CYCLE. WILL STILL MENTION AN ISOLATED SHOWER THROUGH 12Z
IN THE EAST CENTRAL ZONES AS A WEAK SHORTWAVE TRANSITIONS INTO
THIS AREA. THE HRRR AND NMM WEST STILL SHOW A THREAT FOR THIS.
FOR THE REST OF THE SHORT TERM PERIOD...MAIN HIGHLIGHTS WILL BE
INCREASING CHANCES OF PRECIPITATION/RAIN SHOWERS ACROSS SOUTHWEST
AND INTO SOUTH CENTRAL NORTH DAKOTA FRIDAY NIGHT. IN ADDITION
AREAS OF FROST WILL ONCE AGAIN BE POSSIBLE ESPECIALLY OUTSIDE OF
THE PRECIPITATION AREAS MENTIONED ABOVE.
THE LATEST WATER VAPOR IMAGERY SHOWS A CLOSED UPPER LOW OVER
CENTRAL/SOUTHERN CALIFORNIA WITH A DEFORMATION ZONE INTO IDAHO.
FURTHER DOWNSTREAM INTO NORTH DAKOTA...A CONSOLIDATED SOUTHWEST
FLOW WITH A COUPLE OF WEAK SHORTWAVES SHIFTING THROUGH GENERATING
MID LEVEL CLOUDS. EXPECTING A DRY DAY TODAY WITH PARTLY TO MOSTLY
CLOUDY CONDITIONS. FOR FRIDAY NIGHT...A COUPLE OF SHORTWAVES
PEELING OFF THE UPPER LOW MOVE INTO SOUTHWEST NORTH DAKOTA. THE
AFOREMENTIONED DEFORMATION ZONE SLIDES INTO SOUTHWEST/SOUTH
CENTRAL NORTH DAKOTA AFTER 06Z SATURDAY. WITH THE DEFORMATION
ZONE/POOLING OF MOISTURE IN PLACE...INCREASED VERTICAL MOTION OVER
THIS AREA PER 850-300MB OMEGA FIELD/DIFFERENTIAL POSITIVE
VORTICITY ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT.
VERTICAL MOTION WILL ALSO BE ENHANCED BY THE RIGHT ENTRANCE REGION
OF A 90KT/300MB JET STREAK EXTENDING FROM SOUTHERN MANITOBA INTO
SOUTHEAST SASKATCHEWAN AND NORTHWEST NORTH DAKOTA. THE RESULT WILL
BE FOR SHOWERS IN THE SOUTHWEST AND CHANCE OF SHOWERS EXTENDING
INTO SOUTH CENTRAL NORTH DAKOTA THROUGH 12Z SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN FORECAST CONCERN INVOLVES DEEP STORM SYSTEM SLOWLY LIFTING
FROM 4 CORNERS REGION SATURDAY MORNING TO SOUTH DAKOTA BY 00Z
MONDAY. 00Z DETERMINISTIC MODELS HAVE SHIFTED FARTHER NORTH WITH
SYSTEM WITH PORTIONS OF SOUTH CENTRAL ND NOW LOOKING AT POSSIBLE
ACCUMULATING SNOW...MAINLY ON SUNDAY. NAM REMAINS A BIT OF AN
OUTLIER...NOT AS FAR NORTH WITH QPF...THOUGH GFS/NAM/SREF ARE IN
DECENT AGREEMENT. GFS DEPICTS 850MB TEMPS AROUND -2C FROM
SOUTHWEST THROUGH EAST-CENTRAL ND BY 18Z SUNDAY COINCIDENT WITH
BROAD AREA OF STRONG 700MB FRONTOGENESIS AND ISENTROPIC LIFT. WPC
WINTER WEATHER DESK DEPICTS AREA OF 6 INCHES PLUS ACROSS EXTREME
SOUTHWEST FOR DAY 3 /SUNDAY/ WITH THE MAIN BULLSEYE FOR HEAVIEST
SNOW ACCUMULATIONS ACROSS NORTHWESTERN SOUTH DAKOTA. SURFACE TEMPS
NEAR/ABOVE FREEZING MAY LIMIT ACCUMULATIONS. NO HEADLINES PLANNED
AT THIS TIME THOUGH THEY MAY BE NEEDED IF MODELS MAINTAIN
CONSISTENCY WITH FUTURE RUNS. FOR NOW WILL ISSUE SPS TO HIGHLIGHT
POTENTIAL STORM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 616 AM CDT FRI MAY 8 2015
KJMS WILL BE ON THE FRINGES OF LOW VFR TO MVFR CIGS UNTIL 21Z
FRIDAY. ALL OTHER TERMINALS WILL REMAIN VFR WITH SCT/BKN CIGS
BETWEEN 4000FT AND 12000FT. MVFR CIGS ALONG WITH -SHRA ARRIVE AT
KDIK FROM 06Z-12Z SATURDAY. SHOWERS IN THE VICINITY AT KBIS BETWEEN
BY 10Z SATURDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...KS
LONG TERM...JNS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
621 AM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 616 AM CDT FRI MAY 8 2015
FORECAST REMAINS ON TRACK. LATEST HOURLY TEMPS DROPPED A DEGREE OR
TWO MOST LOCATIONS...NEAR 30 NORTH AND LOW/MID 30S ELSEWHERE.
FROST ADVISORY WILL CONTINUE UNTIL 8 AM CDT. NO CHANGES MADE OTHER
THAN BLENDING TO LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN HIGHLIGHT IN THE NEAR TERM PERIOD IS THE ONGOING FROST
ADVISORY. CLOUDS VARYING BETWEEN PARTLY CLOUDY AND MOSTLY CLOUDY
IN THE ADVISORY AREA. THE COLDEST TEMPERATURES ARE RESIDING IN THE
NORTHWEST WITH MID 30S WHICH IS LIKELY RESULTING IN AREAS OF
FROST. WILL LET THE ADVISORY CONTINUE THROUGH AT LEAST THE NEXT
UPDATE CYCLE. WILL STILL MENTION AN ISOLATED SHOWER THROUGH 12Z
IN THE EAST CENTRAL ZONES AS A WEAK SHORTWAVE TRANSITIONS INTO
THIS AREA. THE HRRR AND NMM WEST STILL SHOW A THREAT FOR THIS.
FOR THE REST OF THE SHORT TERM PERIOD...MAIN HIGHLIGHTS WILL BE
INCREASING CHANCES OF PRECIPITATION/RAIN SHOWERS ACROSS SOUTHWEST
AND INTO SOUTH CENTRAL NORTH DAKOTA FRIDAY NIGHT. IN ADDITION
AREAS OF FROST WILL ONCE AGAIN BE POSSIBLE ESPECIALLY OUTSIDE OF
THE PRECIPITATION AREAS MENTIONED ABOVE.
THE LATEST WATER VAPOR IMAGERY SHOWS A CLOSED UPPER LOW OVER
CENTRAL/SOUTHERN CALIFORNIA WITH A DEFORMATION ZONE INTO IDAHO.
FURTHER DOWNSTREAM INTO NORTH DAKOTA...A CONSOLIDATED SOUTHWEST
FLOW WITH A COUPLE OF WEAK SHORTWAVES SHIFTING THROUGH GENERATING
MID LEVEL CLOUDS. EXPECTING A DRY DAY TODAY WITH PARTLY TO MOSTLY
CLOUDY CONDITIONS. FOR FRIDAY NIGHT...A COUPLE OF SHORTWAVES
PEELING OFF THE UPPER LOW MOVE INTO SOUTHWEST NORTH DAKOTA. THE
AFOREMENTIONED DEFORMATION ZONE SLIDES INTO SOUTHWEST/SOUTH
CENTRAL NORTH DAKOTA AFTER 06Z SATURDAY. WITH THE DEFORMATION
ZONE/POOLING OF MOISTURE IN PLACE...INCREASED VERTICAL MOTION OVER
THIS AREA PER 850-300MB OMEGA FIELD/DIFFERENTIAL POSITIVE
VORTICITY ADVECTION WILL LEAD TO PRECIPITATION DEVELOPMENT.
VERTICAL MOTION WILL ALSO BE ENHANCED BY THE RIGHT ENTRANCE REGION
OF A 90KT/300MB JET STREAK EXTENDING FROM SOUTHERN MANITOBA INTO
SOUTHEAST SASKATCHEWAN AND NORTHWEST NORTH DAKOTA. THE RESULT WILL
BE FOR SHOWERS IN THE SOUTHWEST AND CHANCE OF SHOWERS EXTENDING
INTO SOUTH CENTRAL NORTH DAKOTA THROUGH 12Z SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN FORECAST CONCERN INVOLVES DEEP STORM SYSTEM SLOWLY LIFTING
FROM 4 CORNERS REGION SATURDAY MORNING TO SOUTH DAKOTA BY 00Z
MONDAY. 00Z DETERMINISTIC MODELS HAVE SHIFTED FARTHER NORTH WITH
SYSTEM WITH PORTIONS OF SOUTH CENTRAL ND NOW LOOKING AT POSSIBLE
ACCUMULATING SNOW...MAINLY ON SUNDAY. NAM REMAINS A BIT OF AN
OUTLIER...NOT AS FAR NORTH WITH QPF...THOUGH GFS/NAM/SREF ARE IN
DECENT AGREEMENT. GFS DEPICTS 850MB TEMPS AROUND -2C FROM
SOUTHWEST THROUGH EAST-CENTRAL ND BY 18Z SUNDAY COINCIDENT WITH
BROAD AREA OF STRONG 700MB FRONTOGENESIS AND ISENTROPIC LIFT. WPC
WINTER WEATHER DESK DEPICTS AREA OF 6 INCHES PLUS ACROSS EXTREME
SOUTHWEST FOR DAY 3 /SUNDAY/ WITH THE MAIN BULLSEYE FOR HEAVIEST
SNOW ACCUMULATIONS ACROSS NORTHWESTERN SOUTH DAKOTA. SURFACE TEMPS
NEAR/ABOVE FREEZING MAY LIMIT ACCUMULATIONS. NO HEADLINES PLANNED
AT THIS TIME THOUGH THEY MAY BE NEEDED IF MODELS MAINTAIN
CONSISTENCY WITH FUTURE RUNS. FOR NOW WILL ISSUE SPS TO HIGHLIGHT
POTENTIAL STORM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 616 AM CDT FRI MAY 8 2015
KJMS WILL BE ON THE FRINGES OF LOW VFR TO MVFR CIGS UNTIL 21Z
FRIDAY. ALL OTHER TERMINALS WILL REMAIN VFR WITH SCT/BKN CIGS
BETWEEN 4000FT AND 12000FT. MVFR CIGS ALONG WITH -SHRA ARRIVE AT
KDIK FROM 06Z-12Z SATURDAY. SHOWERS IN THE VICINITY AT KBIS BETWEEN
BY 10Z SATURDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 8 AM CDT /7 AM MDT/ THIS MORNING FOR
NDZ001>005-009>013-017>023-031>036-040>044.
&&
$$
UPDATE...JNS
SHORT TERM...KS
LONG TERM...JNS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
348 AM CDT FRI MAY 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN HIGHLIGHT IN THE NEAR TERM PERIOD IS THE ONGOING FROST
ADVISORY. CLOUDS VARYING BETWEEN PARTLY CLOUDY AND MOSTLY CLOUDY
IN THE ADVISORY AREA. THE COLDEST TEMPERATURES ARE RESIDING IN THE
NORTHWEST WITH MID 30S WHICH IS LIKELY RESULTING IN AREAS OF
FROST. WILL LET THE ADVISORY CONTINUE THROUGH AT LEAST THE NEXT
UPDATE CYCLE. WILL STILL MENTION AN ISOLATED SHOWER THROUGH 12Z
IN THE EAST CENTRAL ZONES AS A WEAK SHORTWAVE TRANSITIONS INTO
THIS AREA. THE HRRR AND NMM WEST STILL SHOW A THREAT FOR THIS.
FOR THE REST OF THE SHORT TERM PERIOD...MAIN HIGHLIGHT WILL BE
INCREASING CHANCES OF PRECIPITATION/RAIN SHOWERS ACROSS SOUTHWEST
AND INTO SOUTH CENTRAL NORTH DAKOTA FRIDAY NIGHT. THE LATEST WATER
VAPOR IMAGERY SHOWS A CLOSED UPPER LOW OVER CENTRAL/SOUTHERN
CALIFORNIA WITH A DEFORMATION ZONE INTO IDAHO. FURTHER DOWNSTREAM
INTO NORTH DAKOTA...A CONSOLIDATED SOUTHWEST FLOW WITH A COUPLE
OF WEAK SHORTWAVES SHIFTING THROUGH GENERATING MID LEVEL CLOUDS.
EXPECTING A DRY DAY TODAY WITH PARTLY TO MOSTLY CLOUDY CONDITIONS.
FOR FRIDAY NIGHT...A COUPLE OF SHORTWAVES PEELING OFF THE UPPER
LOW MOVE INTO SOUTHWEST NORTH DAKOTA. THE AFOREMENTIONED
DEFORMATION ZONE SLIDES INTO SOUTHWEST/SOUTH CENTRAL NORTH DAKOTA
AFTER 06Z SATURDAY. WITH THE DEFORMATION ZONE/POOLING OF MOISTURE
IN PLACE...INCREASED VERTICAL MOTION OVER THIS AREA PER 850-300MB
OMEGA FIELD/DIFFERENTIAL POSITIVE VORTICITY ADVECTION WILL LEAD TO
PRECIPITATION DEVELOPMENT. VERTICAL MOTION WILL ALSO BE ENHANCED
BY THE RIGHT ENTRANCE REGION OF A 90KT/300MB JET STREAK EXTENDING
FROM SOUTHERN MANITOBA INTO SOUTHEAST SASKATCHEWAN AND NORTHWEST
NORTH DAKOTA. THE RESULT WILL BE FOR SHOWERS IN THE SOUTHWEST AND
CHANCE OF SHOWERS EXTENDING INTO SOUTH CENTRAL NORTH DAKOTA
THROUGH 12Z SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 202 AM CDT FRI MAY 8 2015
MAIN FORECAST CONCERN INVOLVES DEEP STORM SYSTEM SLOWLY LIFTING
FROM 4 CORNERS REGION SATURDAY MORNING TO SOUTH DAKOTA BY 00Z
MONDAY. 00Z DETERMINISTIC MODELS HAVE SHIFTED FARTHER NORTH WITH
SYSTEM WITH PORTIONS OF SOUTH CENTRAL ND NOW LOOKING AT POSSIBLE
ACCUMULATING SNOW...MAINLY ON SUNDAY. NAM REMAINS A BIT OF AN
OUTLIER...NOT AS FAR NORTH WITH QPF...THOUGH GFS/NAM/SREF ARE IN
DECENT AGREEMENT. GFS DEPICTS 850MB TEMPS AROUND -2C FROM
SOUTHWEST THROUGH EAST-CENTRAL ND BY 18Z SUNDAY COINCIDENT WITH
BROAD AREA OF STRONG 700MB FRONTOGENESIS AND ISENTROPIC LIFT. WPC
WINTER WEATHER DESK DEPICTS AREA OF 6 INCHES PLUS ACROSS EXTREME
SOUTHWEST FOR DAY 3 /SUNDAY/ WITH THE MAIN BULLSEYE FOR HEAVIEST
SNOW ACCUMULATIONS ACROSS NORTHWESTERN SOUTH DAKOTA. SURFACE TEMPS
NEAR/ABOVE FREEZING MAY LIMIT ACCUMULATIONS. NO HEADLINES PLANNED
AT THIS TIME THOUGH THEY MAY BE NEEDED IF MODELS MAINTAIN
CONSISTENCY WITH FUTURE RUNS. FOR NOW WILL ISSUE SPS TO HIGHLIGHT
POTENTIAL STORM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 202 AM CDT FRI MAY 8 2015
LOW VFR TO POSSIBLY MVFR CIGS CAN BE EXPECTED IN KJMS THROUGH 15Z
FRIDAY. THE REST OF THE TERMINALS WILL EXPERIENCE VFR CIGS WITH
SCT TO BKN MID LEVEL CLOUDS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 8 AM CDT /7 AM MDT/ THIS MORNING FOR
NDZ001>005-009>013-017>023-031>036-040>044.
&&
$$
SHORT TERM...KS
LONG TERM...JNS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
351 PM EDT FRI MAY 8 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT
AND EARLY SATURDAY AS AN UPPER LEVEL RIDGE MOVES EAST TO NEW
ENGLAND. THE FRONT WILL STALL NEAR THE REGION SATURDAY NIGHT AND SUNDAY
AND THEN MOVE BACK NORTH AS A WARM FRONT MONDAY AS LOW PRESSURE
MOVES THROUGH THE CENTRAL GREAT LAKES.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
FOR THIS EVENING TO AREAS OF CONCERN ONE THE NERN OHIO/NWRN PA
AREA WHERE THE LAKE BREEZE COULD TOUCH OFF A SHOWER OR
THUNDERSTORM. THE OTHER AREA IS NORTHWEST OHIO WHERE INSTABILITY
FROM NRN INDIANA AND SERN LWR MI WILL DRIFT JUST INTO THE AREA
THROUGH THE EVENING BEFORE DROPPING BACK THROUGH LATE EVENING.
SCATTERED TSTSMS HAVE DEVELOPED FROM THE THUMB OF MI SSW ACROSS
NRN INDIANA INTO CENTRAL IL AND CAPES ON THE RUC ARE FORECAST TO
BE FROM 1000 TO 1800J/KG IN THE AREA. OVERNIGHT AM EXPECTING
CONVECTION FROM CENTRAL ILLINOIS TO REACH INTO THE WESTERN
COUNTIES AS WELL. THIS CONVECTION IS FROM A COMPLEX THAT MOVES
THROUGH THE SOUTHERN PLAINS YDAY AND HELD TOGETHER LAST NIGHT AND
TODAY. THIS TIMES IN 08-10Z. LOWS TONIGHT SHOULD CONTINUE MILD
MAINLY IN THE LOWER 60S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
COLD FRONT SHOULD EXTEND FROM NEAR THE THUMB OF MICHIGAN SOUTHWEST
INTO MO AND KS. THE NAM SHOWS A WAVE MOVING NORTHEAST ALONG THE
FRONT SATURDAY THAT WILL LIKELY STALL IT OUT TO OUR NORTHWEST FOR
THE DAY. THE WAVE PASSES TO OUR NORTH AND NORTHEAST SATURDAY
EVENING/NIGHT. SOME DISAGREEMENT FROM THE NAM TO THE GFS AS TO HOW
MUCH NW PUSH THERE WILL BE TO FORCE THE COLD FRONT INTO THE AREA.
THE GFS BRINGS NWLY FLOW INTO THE AREA LATE SATURDAY NIGHT AND
SUNDAY WHILE THE NAM NO SO MUCH. WILL SIDE MORE TOWARDS THE NAM
AND BLEND HIGHS FOR SUNDAY. WHEREVER THE FRONT STALLS IT SHOULD
MOVE NORTH ON MONDAY AS LOW PRESSURE MOVES INTO THE MIDWEST. WITH
THE UPPER RIDGE AXIS TO OUR EAST AND UPPER LOW PRESSURE MOVING OUT
OF THE FOUR CORNERS INTO THE CENTRAL PLAINS...FLOW ALOFT WILL BE
SWLY WHILE LOW LEVEL FLOW WILL BE FROM THE SOUTH/SOUTHWEST. THIS
WILL BE FAVORABLE FOR INCREASED CONVECTION ACROSS THE AREA THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK. BEST CHANCE FOR
THUNDERSTORMS SHOULD BE LATE TONIGHT WEST AND THEN THROUGH THE DAY
SATURDAY WEST TO EAST AS CONVECTION MOVES THROUGH. AGAIN SUNDAY
INTO SUNDAY NIGHT AS MOISTURE WITH LOW TO OUR WEST OVERRUNS THE
STATIONARY/WARM FRONT. WILL CONTINUE WITH LIKELY POPS MONDAY
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MUCH COOLER WEATHER RETURNS DURING THE EXTENDED FORECAST. THE COLD
FRONT WILL BE EAST OF THE FORECAST AREA BY TUESDAY MORNING BUT THE
COLD ADVECTION WILL CONTINUE THROUGH THE DAY. TEMPERATURES MAY BE
ABLE TO REBOUND A FEW DEGREES DURING THE MORNING...MAINLY
EAST...WITH THE COLDER AIR SPREADING WEST TO EAST DURING THE
AFTERNOON AND EVENING. LOWS ON TUESDAY NIGHT WILL REACH THE LOWER
40S IN MANY AREAS. A FAIRLY THICK CU DECK SHOULD DEVELOP ON
WEDNESDAY WITH STEEP LOW LEVEL LAPSE RATES. HIGHS WILL GENERALLY BE
IN THE 50S...ALTHOUGH A FEW LOCATIONS ALONG THE EAST LAKESHORE MAY
STRUGGLE TO GET THERE. STRONG HIGH PRESSURE WILL BUILD SOUTH OUT OF
CANADA ON WEDNESDAY AND MAINTAIN DRY CONDITIONS ON THURSDAY. WE WILL
HAVE TO KEEP AN EYE ON THE FROST POTENTIAL FOR WEDNESDAY NIGHT. BEST
CHANCES APPEAR TO BE OVER THE HIGHER TERRAIN OF NW PA BUT ALSO
POSSIBLE IN PORTIONS OF NORTHEAST OHIO.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS IN PLACE TO START THE TAF CYCLE WITH CUMULUS CLOUDS
DEVELOPING AROUND 6K FEET. MOISTURE IS INCREASING FROM THE WEST AND
A FEW SHOWERS OR ISOLATED THUNDERSTORMS MAY TRY TO SNEAK INTO THE
TOL AREA AFTER 21Z. BETTER CHANCES WILL BE AFTER 06Z AS MOISTURE
CONTINUES TO INCREASE. AN ISOLATED SHOWER OR THUNDERSTORM WILL ALSO
BE POSSIBLE IN NORTHEAST OH/NORTHWEST PA THIS AFTERNOON BUT CHANCES
OF IMPACTING A TERMINAL ARE TOO LOW TO INCLUDE IN ANY FORECASTS AT
THIS TIME. MVFR VISIBILITIES MAY DEVELOP LATE TONIGHT...MAINLY IN NW
OHIO AS DEWPOINTS CONTINUE TO INCREASE. OTHERWISE SCATTERED SHOWERS
AND THUNDERSTORMS EXPECTED DURING THE AFTERNOON/EVENING ON SATURDAY.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SATURDAY
AFTERNOON THROUGH MONDAY NIGHT.
&&
.MARINE...
WINDS WILL REMAIN 15 KNOTS OR LESS ON LAKE ERIE INTO MONDAY WITH
WEAK LAKE/LAND BREEZE CIRCULATIONS. LOW PRESSURE TRACKING THROUGH
THE CENTRAL GREAT LAKES WILL PULL A COLD FRONT EAST ACROSS THE AREA
FROM MONDAY NIGHT INTO TUESDAY. SOUTHWEST TO WESTERLY WINDS WILL
INCREASE TO NEAR 20 KNOTS ON TUESDAY AND TUESDAY NIGHT AND SMALL
CRAFT ADVISORIES MAY BE NEEDED ON THE EAST HALF OF THE LAKE AS WAVES
BUILD. HIGH PRESSURE WILL RETURN FOR THE SECOND HALF OF NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1226 PM EDT FRI MAY 8 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE WEATHER ACROSS
THE REGION TODAY. A FRONTAL BOUNDARY WILL APPROACH THE LOCAL AREA
FROM THE NORTHWEST ON SATURDAY AND THEN STALL NEAR LAKE ERIE
SATURDAY NIGHT OR SUNDAY. THE FRONT WILL MOVE BACK NORTH AS A WARM FRONT
EARLY NEXT WEEK AS AN AREA OF STRONG LOW PRESSURE MOVES FROM THE
CENTRAL PLAINS TO NORTHERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...NO BIG CHANGES FOR THE AFTERNOON UPDATE.
ORIGINAL...SKIES REMAIN MOSTLY CLEAR THIS MORNING. ANOTHER WARM
SUMMER LIKE DAY IS IN STORE FOR THE AREA. A COUPLE OF RECORD HIGHS
WILL BE CHALLENGED OR BROKEN TODAY. 850 MB TEMPS ARE FORECAST TO
BE JUST A TAD COOLER THAN THURSDAY. BUT GIVEN A WARMER START
EXPECT HIGH TEMPS TO BE FAIRLY CLOSE TO YESTERDAYS VALUES INLAND
AREAS. THERE SHOULD BE ENOUGH OF A PRESSURE GRADIENT TO KEEP THE
LAKE BREEZE FAIRLY CLOSE TO THE SHORELINE TODAY SO PLACES LIKE
KBKL AND KERI SHOULD BE A HANDFUL OF DEGREES WARMER THAN THURSDAY.
SURFACE DEWPOINTS CURRENTLY ARE NOT AS HIGH AS PROGGED BY THE
GUIDANCE BUT SHOULD COME UP SOME TODAY. REALLY NOT MUCH IN THE WAY
OF FORCING TODAY BUT SOME WEAK LOW LEVEL MOISTURE CONVERGENCE
COULD KICK OFF SOME SHOWERS OR STORMS OVER FAR NW OHIO. A FEW
STORMS COULD ALSO FIRE ALONG THE LAKE BREEZE BOUNDARY EAST OF KCLE
LATER TODAY. SOME OF NEWER GUIDANCE INCLUDING THE LATEST HRRR PICK
UP ON THAT SCENARIO. THE PREVIOUS FORECAST ALREADY HAD A MENTION
SO WILL STICK WITH IT FOR NOW.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE FRONTAL SYSTEM OVER THE WESTERN GREAT LAKES WILL CONTINUE TO
INCH TOWARD THE LOCAL AREA THE NEXT COUPLE OF DAYS. AS THIS
HAPPENS PRECIP CHANCES WILL INCREASE FROM NORTHWEST TO SOUTHEAST.
VERY LITTLE SHEAR AND UPPER SUPPORT EXPECTED OVER THE WEEKEND SO
NO ORGANIZED CONVECTION IS EXPECTED. THE SHOWERS AND STORMS THAT
DO DEVELOP WILL LIKELY BE SCATTERED IN NATURE. RIGHT NOW IT
APPEARS BEST CHANCES FOR WIDESPREAD PRECIP WILL PROBABLY NOT COME
TILL LATER MONDAY AND MONDAY NIGHT. TILL THEN WILL NEED MAINLY LIKELY
POPS IN NW OHIO WITH NO MORE THAN CHANCE OF SCATTERED WORDING
ACROSS THE REMAINDER OF THE AREA. IT`S STILL TOUGH TO TELL IF THE
FRONT WILL MAKE IT ACROSS THE LAKE BEFORE IT STALLS ON SUNDAY. THE
NEW GUIDANCE CONTINUES TO SHOW AN AREA OF STRONG LOW PRESSURE
DEVELOPING OVER THE PLAINS THIS WEEKEND. THIS LOW WILL MOVE TO THE
NORTHERN LAKES ON MONDAY CAUSING THE FRONT TO LIFT BACK TO THE
NORTH. AS THIS HAPPENS THE LOCAL AREA COULD SEE A 12 TO 18 HOUR
PERIOD OF MAINLY DRY WEATHER. THE MORE WIDESPREAD PRECIP MENTIONED
ABOVE WILL COME AS THE TRAILING COLD FRONT FINALLY APPROACHES LATE
IN THE SHORT TERM PERIOD. IT HAS BEEN FAIRLY DRY SO FAR THIS MONTH
BUT THINK MOST OF THE AREA WILL SEE AT LEAST A HALF INCH OF
PRECIP THE NEXT FEW DAYS. TEMPS WILL REMAIN A GOOD 15 DEGREES
ABOVE NORMAL DURING THE PERIOD WITH HIGHS MAINLY IN THE LOWER TO
MIDDLE 80S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
BOTH THE ECMWF AND GFS TRACK LOW PRESSURE SYSTEM ACROSS THE EASTERN
LAKES TUESDAY...THEN OFF THE NEW ENGLAND COAST ON WEDNESDAY. BEHIND
THE FRONT MUCH COLDER AIR SPILLS OVER THE AREA. GFS CONTINUES TO BE
MUCH COLDER THAN THE LATEST ECMWF. BY WEDNESDAY EVENING THE GFS
850 MB TEMPERATURES PLUNGE TO -4C WHILE THE ECMWF ONLY TO +4C. FOR
NOW WILL CONTINUE TO SPIT THE DIFFERENCE ON THE TEMPS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE TODAY WITH HIGH PRESSURE CENTERED
OVER THE EASTERN LAKES. MAY SEE SOME TSRA EXTREME NW OHIO LATE
THIS AFTERNOON WITH CAPES UP AROUND 1500 J/KG. BUT WITH STRONG
UPPER LEVEL RIDGE OVER AREA STILL HAVE DOUBTS SO FOR TAFS JUST
WENT WITH VCTS NW OHIO LATE THIS AFTERNOON. GRADIENT BORDERLINE
FOR LAKE BREEZE TO DEVELOP THIS AFTERNOON. IF IT DOES WILL BE FROM
CLE EAST.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AS A FRONT APPROACHES LATE
SATURDAY AND SUNDAY. NON VFR AS WELL ON MONDAY WITH THE FRONT.
&&
.MARINE...
LIGHT SOUTH FLOW OVER THE LAKE WILL CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE REMAINS OVER THE EASTERN LAKES. SOUTHWEST WINDS WILL
INCREASE MONDAY NIGHT AND TUESDAY AHEAD OF A LOW PRESSURE SYSTEM
MOVES INTO THE CENTRAL LAKES. TRAILING COLD FRONT WILL MOVE ACROSS
LAKE ERIE ON TUESDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED
FOR TUESDAY AND TUESDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...TK/KUBINA
SHORT TERM...KUBINA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
954 AM EDT FRI MAY 8 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE WEATHER ACROSS
THE REGION TODAY. A FRONTAL BOUNDARY WILL APPROACH THE LOCAL AREA
FROM THE NORTHWEST ON SATURDAY AND THEN STALL NEAR LAKE ERIE
SATURDAY NIGHT OR SUNDAY. THE FRONT WILL MOVE BACK NORTH AS A WARM FRONT
EARLY NEXT WEEK AS AN AREA OF STRONG LOW PRESSURE MOVES FROM THE
CENTRAL PLAINS TO NORTHERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...NO BIG CHANGES FOR THE MORNING UPDATE.
ORIGINAL...SKIES REMAIN MOSTLY CLEAR THIS MORNING. ANOTHER WARM
SUMMER LIKE DAY IS IN STORE FOR THE AREA. A COUPLE OF RECORD HIGHS
WILL BE CHALLENGED OR BROKEN TODAY. 850 MB TEMPS ARE FORECAST TO
BE JUST A TAD COOLER THAN THURSDAY. BUT GIVEN A WARMER START
EXPECT HIGH TEMPS TO BE FAIRLY CLOSE TO YESTERDAYS VALUES INLAND
AREAS. THERE SHOULD BE ENOUGH OF A PRESSURE GRADIENT TO KEEP THE
LAKE BREEZE FAIRLY CLOSE TO THE SHORELINE TODAY SO PLACES LIKE
KBKL AND KERI SHOULD BE A HANDFUL OF DEGREES WARMER THAN THURSDAY.
SURFACE DEWPOINTS CURRENTLY ARE NOT AS HIGH AS PROGGED BY THE
GUIDANCE BUT SHOULD COME UP SOME TODAY. REALLY NOT MUCH IN THE WAY
OF FORCING TODAY BUT SOME WEAK LOW LEVEL MOISTURE CONVERGENCE
COULD KICK OFF SOME SHOWERS OR STORMS OVER FAR NW OHIO. A FEW
STORMS COULD ALSO FIRE ALONG THE LAKE BREEZE BOUNDARY EAST OF KCLE
LATER TODAY. SOME OF NEWER GUIDANCE INCLUDING THE LATEST HRRR PICK
UP ON THAT SCENARIO. THE PREVIOUS FORECAST ALREADY HAD A MENTION
SO WILL STICK WITH IT FOR NOW.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE FRONTAL SYSTEM OVER THE WESTERN GREAT LAKES WILL CONTINUE TO
INCH TOWARD THE LOCAL AREA THE NEXT COUPLE OF DAYS. AS THIS
HAPPENS PRECIP CHANCES WILL INCREASE FROM NORTHWEST TO SOUTHEAST.
VERY LITTLE SHEAR AND UPPER SUPPORT EXPECTED OVER THE WEEKEND SO
NO ORGANIZED CONVECTION IS EXPECTED. THE SHOWERS AND STORMS THAT
DO DEVELOP WILL LIKELY BE SCATTERED IN NATURE. RIGHT NOW IT
APPEARS BEST CHANCES FOR WIDESPREAD PRECIP WILL PROBABLY NOT COME
TILL LATER MONDAY AND MONDAY NIGHT. TILL THEN WILL NEED MAINLY LIKELY
POPS IN NW OHIO WITH NO MORE THAN CHANCE OF SCATTERED WORDING
ACROSS THE REMAINDER OF THE AREA. IT`S STILL TOUGH TO TELL IF THE
FRONT WILL MAKE IT ACROSS THE LAKE BEFORE IT STALLS ON SUNDAY. THE
NEW GUIDANCE CONTINUES TO SHOW AN AREA OF STRONG LOW PRESSURE
DEVELOPING OVER THE PLAINS THIS WEEKEND. THIS LOW WILL MOVE TO THE
NORTHERN LAKES ON MONDAY CAUSING THE FRONT TO LIFT BACK TO THE
NORTH. AS THIS HAPPENS THE LOCAL AREA COULD SEE A 12 TO 18 HOUR
PERIOD OF MAINLY DRY WEATHER. THE MORE WIDESPREAD PRECIP MENTIONED
ABOVE WILL COME AS THE TRAILING COLD FRONT FINALLY APPROACHES LATE
IN THE SHORT TERM PERIOD. IT HAS BEEN FAIRLY DRY SO FAR THIS MONTH
BUT THINK MOST OF THE AREA WILL SEE AT LEAST A HALF INCH OF
PRECIP THE NEXT FEW DAYS. TEMPS WILL REMAIN A GOOD 15 DEGREES
ABOVE NORMAL DURING THE PERIOD WITH HIGHS MAINLY IN THE LOWER TO
MIDDLE 80S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
BOTH THE ECMWF AND GFS TRACK LOW PRESSURE SYSTEM ACROSS THE EASTERN
LAKES TUESDAY...THEN OFF THE NEW ENGLAND COAST ON WEDNESDAY. BEHIND
THE FRONT MUCH COLDER AIR SPILLS OVER THE AREA. GFS CONTINUES TO BE
MUCH COLDER THAN THE LATEST ECMWF. BY WEDNESDAY EVENING THE GFS
850 MB TEMPERATURES PLUNGE TO -4C WHILE THE ECMWF ONLY TO +4C. FOR
NOW WILL CONTINUE TO SPIT THE DIFFERENCE ON THE TEMPS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE TODAY WITH HIGH PRESSURE CENTERED
OVER THE EASTERN LAKES. MAY SEE SOME TSRA EXTREME NW OHIO LATE
THIS AFTERNOON WITH CAPES UP AROUND 1500 J/KG. BUT WITH STRONG
UPPER LEVEL RIDGE OVER AREA STILL HAVE DOUBTS SO FOR TAFS JUST
WENT WITH VCTS NW OHIO LATE THIS AFTERNOON. GRADIENT BORDERLINE
FOR LAKE BREEZE TO DEVELOP THIS AFTERNOON. IF IT DOES WILL BE FROM
CLE EAST.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AS A FRONT APPROACHES LATE
SATURDAY AND SUNDAY. NON VFR AS WELL ON MONDAY WITH THE FRONT.
&&
.MARINE...
LIGHT SOUTH FLOW OVER THE LAKE WILL CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE REMAINS OVER THE EASTERN LAKES. SOUTHWEST WINDS WILL
INCREASE MONDAY NIGHT AND TUESDAY AHEAD OF A LOW PRESSURE SYSTEM
MOVES INTO THE CENTRAL LAKES. TRAILING COLD FRONT WILL MOVE ACROSS
LAKE ERIE ON TUESDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED
FOR TUESDAY AND TUESDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...TK/KUBINA
SHORT TERM...KUBINA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
652 AM EDT FRI MAY 8 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE WEATHER ACROSS
THE REGION TODAY. A FRONTAL BOUNDARY WILL APPROACH THE LOCAL AREA
FROM THE NORTHWEST ON SATURDAY AND THEN STALL NEAR LAKE ERIE
SATURDAY NIGHT OR SUNDAY. THE FRONT WILL MOVE BACK NORTH AS A WARM FRONT
EARLY NEXT WEEK AS AN AREA OF STRONG LOW PRESSURE MOVES FROM THE
CENTRAL PLAINS TO NORTHERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
SKIES REMAIN MOSTLY CLEAR THIS MORNING. ANOTHER WARM SUMMER LIKE
DAY IS IN STORE FOR THE AREA. A COUPLE OF RECORD HIGHS WILL BE
CHALLENGED OR BROKEN TODAY. 850 MB TEMPS ARE FORECAST TO BE JUST A
TAD COOLER THAN THURSDAY. BUT GIVEN A WARMER START EXPECT HIGH
TEMPS TO BE FAIRLY CLOSE TO YESTERDAYS VALUES INLAND AREAS. THERE
SHOULD BE ENOUGH OF A PRESSURE GRADIENT TO KEEP THE LAKE BREEZE
FAIRLY CLOSE TO THE SHORELINE TODAY SO PLACES LIKE KBKL AND KERI
SHOULD BE A HANDFUL OF DEGREES WARMER THAN THURSDAY. SURFACE
DEWPOINTS CURRENTLY ARE NOT AS HIGH AS PROGGED BY THE GUIDANCE BUT
SHOULD COME UP SOME TODAY. REALLY NOT MUCH IN THE WAY OF FORCING
TODAY BUT SOME WEAK LOW LEVEL MOISTURE CONVERGENCE COULD KICK OFF
SOME SHOWERS OR STORMS OVER FAR NW OHIO. A FEW STORMS COULD ALSO FIRE
ALONG THE LAKE BREEZE BOUNDARY EAST OF KCLE LATER TODAY. SOME OF
NEWER GUIDANCE INCLUDING THE LATEST HRRR PICK UP ON THAT
SCENARIO. THE PREVIOUS FORECAST ALREADY HAD A MENTION SO WILL
STICK WITH IT FOR NOW.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THE FRONTAL SYSTEM OVER THE WESTERN GREAT LAKES WILL CONTINUE TO
INCH TOWARD THE LOCAL AREA THE NEXT COUPLE OF DAYS. AS THIS
HAPPENS PRECIP CHANCES WILL INCREASE FROM NORTHWEST TO SOUTHEAST.
VERY LITTLE SHEAR AND UPPER SUPPORT EXPECTED OVER THE WEEKEND SO
NO ORGANIZED CONVECTION IS EXPECTED. THE SHOWERS AND STORMS THAT
DO DEVELOP WILL LIKELY BE SCATTERED IN NATURE. RIGHT NOW IT
APPEARS BEST CHANCES FOR WIDESPREAD PRECIP WILL PROBABLY NOT COME
TILL LATER MONDAY AND MONDAY NIGHT. TILL THEN WILL NEED MAINLY LIKELY
POPS IN NW OHIO WITH NO MORE THAN CHANCE OF SCATTERED WORDING
ACROSS THE REMAINDER OF THE AREA. IT`S STILL TOUGH TO TELL IF THE
FRONT WILL MAKE IT ACROSS THE LAKE BEFORE IT STALLS ON SUNDAY. THE
NEW GUIDANCE CONTINUES TO SHOW AN AREA OF STRONG LOW PRESSURE
DEVELOPING OVER THE PLAINS THIS WEEKEND. THIS LOW WILL MOVE TO THE
NORTHERN LAKES ON MONDAY CAUSING THE FRONT TO LIFT BACK TO THE
NORTH. AS THIS HAPPENS THE LOCAL AREA COULD SEE A 12 TO 18 HOUR
PERIOD OF MAINLY DRY WEATHER. THE MORE WIDESPREAD PRECIP MENTIONED
ABOVE WILL COME AS THE TRAILING COLD FRONT FINALLY APPROACHES LATE
IN THE SHORT TERM PERIOD. IT HAS BEEN FAIRLY DRY SO FAR THIS MONTH
BUT THINK MOST OF THE AREA WILL SEE AT LEAST A HALF INCH OF
PRECIP THE NEXT FEW DAYS. TEMPS WILL REMAIN A GOOD 15 DEGREES
ABOVE NORMAL DURING THE PERIOD WITH HIGHS MAINLY IN THE LOWER TO
MIDDLE 80S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
BOTH THE ECMWF AND GFS TRACK LOW PRESSURE SYSTEM ACROSS THE EASTERN
LAKES TUESDAY...THEN OFF THE NEW ENGLAND COAST ON WEDNESDAY. BEHIND
THE FRONT MUCH COLDER AIR SPILLS OVER THE AREA. GFS CONTINUES TO BE
MUCH COLDER THAN THE LATEST ECMWF. BY WEDNESDAY EVENING THE GFS
850 MB TEMPERATURES PLUNGE TO -4C WHILE THE ECMWF ONLY TO +4C. FOR
NOW WILL CONTINUE TO SPIT THE DIFFERENCE ON THE TEMPS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE TODAY WITH HIGH PRESSURE CENTERED
OVER THE EASTERN LAKES. MAY SEE SOME TSRA EXTREME NW OHIO LATE
THIS AFTERNOON WITH CAPES UP AROUND 1500 J/KG. BUT WITH STRONG
UPPER LEVEL RIDGE OVER AREA STILL HAVE DOUBTS SO FOR TAFS JUST
WENT WITH VCTS NW OHIO LATE THIS AFTERNOON. GRADIENT BORDERLINE
FOR LAKE BREEZE TO DEVELOP THIS AFTERNOON. IF IT DOES WILL BE FROM
CLE EAST.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AS A FRONT APPROACHES LATE
SATURDAY AND SUNDAY. NON VFR AS WELL ON MONDAY WITH THE FRONT.
&&
.MARINE...
LIGHT SOUTH FLOW OVER THE LAKE WILL CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE REMAINS OVER THE EASTERN LAKES. SOUTHWEST WINDS WILL
INCREASE MONDAY NIGHT AND TUESDAY AHEAD OF A LOW PRESSURE SYSTEM
MOVES INTO THE CENTRAL LAKES. TRAILING COLD FRONT WILL MOVE ACROSS
LAKE ERIE ON TUESDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED
FOR TUESDAY AND TUESDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
309 AM EDT FRI MAY 8 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE WEATHER ACROSS
THE REGION TODAY. A FRONTAL BOUNDARY WILL APPROACH THE LOCAL AREA
FROM THE NORTHWEST ON SATURDAY AND THEN STALL NEAR LAKE ERIE
SATURDAY NIGHT OR SUNDAY. THE FRONT WILL MOVE BACK NORTH AS A WARM FRONT
EARLY NEXT WEEK AS AN AREA OF STRONG LOW PRESSURE MOVES FROM THE
CENTRAL PLAINS TO NORTHERN GREAT LAKES.
&&
.NEAR TERM /THROUGH TODAY/...
SKIES REMAIN MOSTLY CLEAR THIS MORNING. ANOTHER WARM SUMMER LIKE
DAY IS IN STORE FOR THE AREA. A COUPLE OF RECORD HIGHS WILL BE
CHALLENGED OR BROKEN TODAY. 850 MB TEMPS ARE FORECAST TO BE JUST A
TAD COOLER THAN THURSDAY. BUT GIVEN A WARMER START EXPECT HIGH
TEMPS TO BE FAIRLY CLOSE TO YESTERDAYS VALUES INLAND AREAS. THERE
SHOULD BE ENOUGH OF A PRESSURE GRADIENT TO KEEP THE LAKE BREEZE
FAIRLY CLOSE TO THE SHORELINE TODAY SO PLACES LIKE KBKL AND KERI
SHOULD BE A HANDFUL OF DEGREES WARMER THAN THURSDAY. SURFACE
DEWPOINTS CURRENTLY ARE NOT AS HIGH AS PROGGED BY THE GUIDANCE BUT
SHOULD COME UP SOME TODAY. REALLY NOT MUCH IN THE WAY OF FORCING
TODAY BUT SOME WEAK LOW LEVEL MOISTURE CONVERGENCE COULD KICK OFF
SOME SHOWERS OR STORMS OVER FAR NW OHIO. A FEW STORMS COULD ALSO FIRE
ALONG THE LAKE BREEZE BOUNDARY EAST OF KCLE LATER TODAY. SOME OF
NEWER GUIDANCE INCLUDING THE LATEST HRRR PICK UP ON THAT
SCENARIO. THE PREVIOUS FORECAST ALREADY HAD A MENTION SO WILL
STICK WITH IT FOR NOW.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
THE FRONTAL SYSTEM OVER THE WESTERN GREAT LAKES WILL CONTINUE TO
INCH TOWARD THE LOCAL AREA THE NEXT COUPLE OF DAYS. AS THIS
HAPPENS PRECIP CHANCES WILL INCREASE FROM NORTHWEST TO SOUTHEAST.
VERY LITTLE SHEAR AND UPPER SUPPORT EXPECTED OVER THE WEEKEND SO
NO ORGANIZED CONVECTION IS EXPECTED. THE SHOWERS AND STORMS THAT
DO DEVELOP WILL LIKELY BE SCATTERED IN NATURE. RIGHT NOW IT
APPEARS BEST CHANCES FOR WIDESPREAD PRECIP WILL PROBABLY NOT COME
TILL LATER MONDAY AND MONDAY NIGHT. TILL THEN WILL NEED MAINLY LIKELY
POPS IN NW OHIO WITH NO MORE THAN CHANCE OF SCATTERED WORDING
ACROSS THE REMAINDER OF THE AREA. IT`S STILL TOUGH TO TELL IF THE
FRONT WILL MAKE IT ACROSS THE LAKE BEFORE IT STALLS ON SUNDAY. THE
NEW GUIDANCE CONTINUES TO SHOW AN AREA OF STRONG LOW PRESSURE
DEVELOPING OVER THE PLAINS THIS WEEKEND. THIS LOW WILL MOVE TO THE
NORTHERN LAKES ON MONDAY CAUSING THE FRONT TO LIFT BACK TO THE
NORTH. AS THIS HAPPENS THE LOCAL AREA COULD SEE A 12 TO 18 HOUR
PERIOD OF MAINLY DRY WEATHER. THE MORE WIDESPREAD PRECIP MENTIONED
ABOVE WILL COME AS THE TRAILING COLD FRONT FINALLY APPROACHES LATE
IN THE SHORT TERM PERIOD. IT HAS BEEN FAIRLY DRY SO FAR THIS MONTH
BUT THINK MOST OF THE AREA WILL SEE AT LEAST A HALF INCH OF
PRECIP THE NEXT FEW DAYS. TEMPS WILL REMAIN A GOOD 15 DEGREES
ABOVE NORMAL DURING THE PERIOD WITH HIGHS MAINLY IN THE LOWER TO
MIDDLE 80S.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
BOTH THE ECMWF AND GFS TRACK LOW PRESSURE SYSTEM ACROSS THE EASTERN
LAKES TUESDAY...THEN OFF THE NEW ENGLAND COAST ON WEDNESDAY. BEHIND
THE FRONT MUCH COLDER AIR SPILLS OVER THE AREA. GFS CONTINUES TO BE
MUCH COLDER THAN THE LATEST ECMWF. BY WEDNESDAY EVENING THE GFS
850 MB TEMPERATURES PLUNGE TO -4C WHILE THE ECMWF ONLY TO +4C. FOR
NOW WILL CONTINUE TO SPIT THE DIFFERENCE ON THE TEMPS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE ENTIRE FORECAST PERIOD AS
HIGH PRESSURE REMAINS CENTERED OVER THE EASTERN LAKES. TSRA MAY
CREEP INTO NW OHIO LATE THIS AFTERNOON WITH CAPES UP AROUND 1500
J/KG. BUT WITH STRONG UPPER LEVEL RIDGE OVER AREA STILL HAVE
DOUBTS SO FOR TAFS JUST WENT WITH VCTS NW OHIO LATE THIS
AFTERNOON.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AS A FRONT APPROACHES LATE
SATURDAY AND SUNDAY. NON VFR AS WELL ON MONDAY WITH THE FRONT.
&&
.MARINE...
LIGHT SOUTH FLOW OVER THE LAKE WILL CONTINUE THROUGH THE WEEKEND AS
HIGH PRESSURE REMAINS OVER THE EASTERN LAKES. SOUTHWEST WINDS WILL
INCREASE MONDAY NIGHT AND TUESDAY AHEAD OF A LOW PRESSURE SYSTEM
MOVES INTO THE CENTRAL LAKES. TRAILING COLD FRONT WILL MOVE ACROSS
LAKE ERIE ON TUESDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED
FOR TUESDAY AND TUESDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS TULSA OK
253 PM CDT FRI MAY 8 2015
.DISCUSSION...
SIGNIFICANT FLOODING AND POTENTIAL SEVERE WEATHER CONCERNS ACROSS
EASTERN OKLAHOMA AND WESTERN ARKANSAS REMAIN ONGOING TODAY...AND
WILL PERSIST THROUGH THE WEEKEND.
AT PRESENT...A WARM FRONT IS EVIDENT IN SURFACE AND SATELLITE
OBSERVATIONS EXTENDING FROM SOUTHWEST OKLAHOMA...NORTHEASTWARD
INTO CENTRAL AND PARTS OF EAST CENTRAL OKLAHOMA...AND BACK
SOUTHEASTWARD THROUGH FAR SOUTHEAST OKLAHOMA. DESTABILIZATION IS
OCCURING TO THE SOUTH OF THE FRONT...WITH LOW TO MID 70S DEW
POINTS PREVALENT. 18Z SOUNDINGS FROM OUN AND FWD ARE INDICATIVE OF
A HIGHLY UNSTABLE ATMOSPHERE...AND MESOANALYSES SHOW A TONGUE OF
THIS INSTABILITY EXTENDING NORTHWARD INTO PORTIONS OF NORTHEAST
AND NORTH CENTRAL OKLAHOMA ROUGHLY BETWEEN THE INTERSTATE 35 AND
HIGHWAY 75 TO 69 CORRIDORS. AS SUCH...ONGOING ACTIVITY IN
SOUTHWEST OKLAHOMA /ASSOCIATED WITH AN UPPER LEVEL SPEED MAX/ MAY
HAVE A TENDENCY TO MOVE/SPREAD TO THE NORTHEAST TOWARD PARTS OF
EAST CENTRAL AND PERHAPS NORTHEAST OKLAHOMA AS OPPOSED TO SIMPLY
THE EAST NEAR THE RED RIVER. THE LOCAL WRF AND THE LATEST
INFORMATION FROM THE HRRR SUPPORT THIS SCENARIO...WITH ADDITIONAL
STORMS LIKELY TO MAKE A MID TO LATE EVENING RUN ALONG THE RED
RIVER IN RESPONSE TO AN INCREASE IN THE LOW LEVEL JET. THE OVERALL
TORNADO THREAT SHOULD BE FAIRLY LOW ACROSS MUCH OF THE FORECAST
AREA...ALTHOUGH A LOCALLY HIGHER THREAT WILL EXIST NEAR THE WARM
FRONT AND ALSO ACROSS FAR SOUTHEAST OKLAHOMA WITH THE INCREASE IN
THE LOW LEVEL JET.
WITH WELL ABOVE NORMAL PRECIPITABLE WATER VALUES AND HIGHLY
EFFICIENT RAINFALL PROCESSES LIKELY TO CONTINUE ACROSS THE
FORECAST AREA...SIGNIFICANT FLOODING CONCERNS WILL
PERSIST...ESPECIALLY IN AREAS THAT HAVE OVERLY WET ANTECEDENT
CONDITIONS. THROUGH THE NEXT 12 TO 18 HOURS...IT APPEARS THAT
SOUTHEAST OKLAHOMA WILL HAVE THE BEST CHANCE OF
FLOODING...ALTHOUGH IT IS BY NO MEANS ZERO IN OTHER PARTS OF
EASTERN OKLAHOMA AND WESTERN ARKANSAS.
AS HAS BEEN SAID A LOT IN THE LAST FEW DAYS...SATURDAY/S SEVERE
THREAT WILL BE VERY DEPENDENT ON WHAT HAPPENS LATER TONIGHT AND
INTO SATURDAY MORNING. STORMS COULD LINGER ACROSS PARTS OF
NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS INTO SATURDAY
MORNING...BEFORE MOVING OUT BY MID MORNING. ADDITIONAL
THUNDERSTORMS SHOULD DEVELOP TO THE WEST...AHEAD OF THE DRYLINE...
EARLY TO MID MORNING...AND BEGIN TO MOVE INTO SOUTHEAST OKLAHOMA
LATE MORNING TO EARLY AFTERNOON. THESE STORMS WILL SPREAD TO THE
EAST AND NORTHEAST FROM THERE. IF SUFFICIENT INSTABILITY CAN
DEVELOP BEHIND THE EARLY MORNING STORMS AND IN ADVANCE OF THE
LATER ROUND...A SEVERE THREAT WILL EXIST IN EASTERN OKLAHOMA
BEGINNING AS SOON AS EARLY AFTERNOON...ALTHOUGH MODEST DEEP LAYER
SHEAR COULD LIMIT THE SEVERITY UNTIL LATER IN THE DAY. A VEERED
LOW LEVEL JET LOOKS TO MOVE INTO PARTS OF EASTERN OKLAHOMA MID TO
LATE AFTERNOON WHICH WOULD LEAD TO AN INCREASE IN THE TORNADO
THREAT.
THE COLD FRONT AND DRYLINE WILL FINALLY MAKE A PUSH TOWARD THE
EAST AND SOUTHEAST LATE SATURDAY AND SATURDAY NIGHT...AS THE MAIN
UPPER LOW FINALLY EJECTS INTO THE CENTRAL PLAINS. THIS SHOULD
BRING ANOTHER CHANCE OF WIDESPREAD THUNDERSTORMS AND HEAVY
RAINFALL...WITH THIS SAME RISK PERSISTING INTO SUNDAY AND SUNDAY
NIGHT UNTIL THE BOUNDARIES FINALLY CLEAR THE REGION. STILL THINK
THE BEST CHANCE OF WIDESPREAD SEVERE WEATHER IN THE FORECAST AREA
MAY BE SUNDAY...ALTHOUGH THE IMPACT MAY NOT BE AS GREAT AS THE
POTENTIAL FOR LATER TODAY AND TOMORROW.
ON THE RAINFALL FRONT...A WIDESPREAD 3 TO 6 INCHES OF RAINFALL
SHOULD OCCUR BEFORE ALL IS SAID AND DONE MONDAY MORNING...WITH
LOCAL AMOUNTS APPROACHING 10 INCHES. WIDESPREAD RIVER FLOODING AND
FLASH FLOOD POTENTIAL MAY VERY WELL END UP BEING THE BIG STORY
FROM THIS EVENT.
EARLY NEXT WEEK THERE SHOULD BE A DAY OR TWO WHERE SURFACE HIGH
PRESSURE LEADS TO A COOL AND DRY PERIOD...BUT MOISTURE MAKES A
QUICK RETURN TOWARD THE MIDDLE PART OF NEXT WEEK...BRINGING MORE
THUNDERSTORMS AND RAINFALL TO THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 67 79 68 78 / 80 80 70 80
FSM 69 81 66 79 / 70 80 60 80
MLC 68 78 69 76 / 80 80 70 80
BVO 65 78 65 78 / 80 80 70 60
FYV 67 77 64 74 / 70 80 60 80
BYV 66 81 65 76 / 70 70 60 80
MKO 68 78 66 76 / 80 80 70 80
MIO 65 80 66 77 / 70 80 70 80
F10 67 77 67 76 / 80 80 70 80
HHW 70 80 68 78 / 70 80 60 80
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH UNTIL 7 AM MONDAY FOR OKZ049-OKZ053-OKZ054-
OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-
OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-
OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...FLASH FLOOD WATCH UNTIL 7 AM MONDAY FOR ARZ001-ARZ002-ARZ010-
ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
LONG TERM....22
AREA FORECAST DISCUSSION
NWS NORMAN OK
1248 PM CDT FRI MAY 8 2015
.DISCUSSION...
THE 18Z AVIATION DISCUSSION FOLLOWS....
&&
.AVIATION...
A STALLED OUTFLOW BOUNDARY FROM NEAR KELK TO KOKC DIVIDES
STRATIFORM LOW CLOUDS TO THE N FROM MORE CONVECTIVE CONDITIONS TO
THE S. TSRA...SOME SEVERE...ARE LIKELY TO TREK E/NE ACROSS OK/N
TX THIS AFTERNOON...WITH THE MOST INTENSE STORMS MAINLY S OF THE
BOUNDARY. IT IS UNCLEAR WHETHER THE LOW CEILINGS WILL IMPROVE
SIGNIFICANTLY TODAY OR NOT. THERE IS A POSSIBILITY AGAIN OF VERY
LOW CEILINGS AND FG...BUT WE EXPECT WINDS TO REMAIN TOO STRONG FOR
THE FG. MUCH LIKE LAST NIGHT...IF WINDS DECREASE UNEXPECTEDLY...FG
WILL BE POSSIBLE. AS A LARGE STORM SYSTEM TO OUR W ADVANCES E
TONIGHT...WE EXPECT WIDESPREAD ELEVATED CONVECTION TO DEVELOP.
EXPECT SCT TO NUMEROUS SHRA AND TSRA LATE TONIGHT INTO EARLY
SATURDAY. TIMING AND POSITION OF THE TSRA IS TOO DIFFICULT TO
FORECAST AT THIS POINT TO INCLUDE IN TAFS. MORE-ORGANIZED
CONVECTIVE DEVELOPMENT IS EXPECTED JUST BEYOND THE RANGE OF THE
TAFS.
CMS
&&
.PREV DISCUSSION... /ISSUED 1043 AM CDT FRI MAY 8 2015/
DISCUSSION...
PERSISTENT CLOUD COVER APPEARS TO BE REDUCING THE SEVERE WEATHER
POTENTIAL SOMEWHAT ACROSS CENTRAL AND NORTHERN OKLAHOMA TODAY.
THAT DOES NOT SIGNIFICANTLY AFFECT THE GRIDDED FORECAST...BUT
THERE MAY BE SOME ADJUSTMENTS TO THE SEVERE WEATHER OUTLOOKS
LATER THIS MORNING.
THE SAME CLOUD COVER HAS SLOWED HEATING ACROSS MUCH OF
OKLAHOMA...AND WE WILL ADJUST THE HOURLY GRIDS ACCORDINGLY.
ADDITIONAL UPDATES MAY BE NEEDED THROUGH THE DAY AS THE EVOLUTION
OF THE CONVECTIVE SYSTEMS BECOMES MORE APPARENT.
PREV DISCUSSION... /ISSUED 331 AM CDT FRI MAY 8 2015/
DISCUSSION...
TODAY WILL BE ANOTHER RATHER COMPLICATED SITUATION WITH REGARDS TO
CONVECTION AND ATTENDANT SEVERE WEATHER THREAT... AS WELL AS
ADDITIONAL HEAVY... POSSIBLY FLOODING RAINFALL. WILL ALSO HAVE
SOME PATCHY FOG TO DEAL WITH FOR A WHILE THIS MORNING.
MANY OF THE MODELS DEPICT MORNING CONVECTION DEVELOPING AS LIFT
BEGINS TO OVERSPREAD THE AREA AHEAD OF A LEAD SHORTWAVE. HOWEVER
THE MODELS DIFFER IN THEIR PLACEMENT OF THIS CONVECTION THROUGH
THE MORNING HOURS. THEY ALSO DIFFER IN HOW TO HANDLE RESIDUAL LOW
LEVEL BOUNDARIES FROM OVERNIGHT CONVECTION. MAIN BOUNDARY THIS
MORNING SHOULD RESIDE TO OUR SOUTH... BUT WOULD EXPECT IT TO TRY
TO LIFT BACK TO THE NORTH AS SOUTHERLY LOW LEVEL FLOW INCREASING
LATER THIS MORNING.
LATEST NAM/GFS DEPICT BOUNDARY LIFTING BACK TO NEAR I-40 CORRIDOR
BY AFTN. FOLLOWING THIS SCENARIO... WHICH ALSO KEEPS MUCH OF THE
MORNING CONVECTION ACROSS NORTHERN HALF OF THE AREA...WOULD AID IN
REINFORCING SURFACE BOUNDARY SOMEWHERE NEAR OR SLIGHTLY SOUTH OF
THE I-40 CORRIDOR BY THIS AFTN... ALTHOUGH OTHER BOUNDARIES WILL
LIKELY BE IN PLACE ACROSS THE AREA. ALTHOUGH THIS WOULD LIMIT
INSTABILITY ACROSS MUCH OF NORTHERN INTO PARTS OF CENTRAL
OKLAHOMA... SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS WOULD REMAIN
IN THE MORE UNSTABLE ENVIRONMENT FOR THE AFTN INTO THE EVENING.
THIS WILL BE THE MORE LIKELY AREA FOR MORE SIGNIFICANT STORMS...
INCLUDING VERY LARGE HAIL... DAMAGING WINDS AND TORNADOES THIS
AFTN AND EVENING.
LATEST FEW RUNS OF HRRR GIVE A DIFFERENT SCENARIO THIS MORNING.
THIS MODEL HAS MORE OF A COMPLEX OF STORMS DEVELOPING AND MOVING
ACROSS THE SOUTHERN HALF OF OKLAHOMA AND THE RED RIVER VALLEY
DURING THE DAY. THIS WOULD LIKELY BE THE MAIN SHOW FOR THE DAY AND
ANY ATTENDANT SEVERE WOULD LIKELY BE ASSOCIATED WITH THIS COMPLEX
OF STORMS... MUCH LIKE WHAT OCCURRED ON THURSDAY. EITHER SCENARIO
WOULD SUGGEST THAT THE SOUTHERN HALF OF OKLAHOMA SOUTH INTO NORTH
TEXAS WOULD BE THE FAVORED LOCATIONS FOR MORE SIGNIFICANT SEVERE
STORMS.
THIS ACTIVITY SHOULD GRADUALLY WEAKEN AND MOVE EAST OF THE AREA
LATE TONIGHT. WE THEN SET THE STAGE FOR ANOTHER DAY OF SEVERE
WEATHER ON SATURDAY. MAIN UPPER TROUGH IS EXPECTED TO SWING OUT
INTO THE PLAINS BY SAT AFTN AND EVENING. MODELS ARE AGAIN SHOWING
SOME MORNING SHOWERS/STORMS DEVELOPING ACROSS WESTERN INTO CENTRAL
SECTIONS OF THE AREA AS LIFT BEGINS TO INFLUENCE THE AREA AHEAD OF
MAIN TROUGH. THINK THAT THIS SHOULD PROGRESS EAST QUICK ENOUGH
THAT ATMOSPHERE SHOULD RECOVER/DESTABILIZE ALONG AND EAST OF THE
DRYLINE BY SAT AFTN ACROSS THE EASTERN OK/TX PANHANDLES INTO
WESTERN PORTIONS OF OKLAHOMA. THE COMBINATION OF EXPECTED
INSTABILITY AND FAVORABLE WIND FIELDS ARE EXPECTED TO LEAD TO THE
DEVELOPMENT OF SUPERCELL THUNDERSTORMS IN THESE AREAS SAT AFTN
CAPABLE OF TORNADOES/VERY LARGE HAIL/DAMAGING WINDS. THESE STORMS
WILL THEN MOVE EAST AND NORTHEAST ACROSS WESTERN OKLAHOMA AND
PERHAPS WESTERN NORTH TEXAS TOWARD THE I-35 CORRIDOR DURING THE
EVENING HOURS.
THIS SYSTEM WILL SLOWLY LIFT NORTH AND EAST SATURDAY NIGHT INTO
SUNDAY. AS THIS OCCURS... A COLD FRONT WILL SLIP SOUTH INTO THE
AREA AND WILL AGAIN BE A FOCUS FOR THUNDERSTORMS... SOME SEVERE
SUNDAY AFTN MAINLY ALONG AND SOUTHEAST OF I-44.
ALL THROUGH THIS TIME WILL BE ADDING TO THE RAINFALL AMOUNTS AND
FLOODING WILL CONTINUE TO BE A CONCERN THROUGH MOTHER`S DAY
WEEKEND. WILL CONT WITH THE CURRENT FLOOD WATCH THAT GOES THROUGH
THE DAY ON SUNDAY.
SHOULD SEE A DAY OR TWO OF MORE TRANQUIL WEATHER TO BEGIN NEXT
WEEK BEFORE MOISTURE BEGINS TO PULL BACK NORTH AND PRECIP CHANCES
RETURN TO THE AREA. RIGHT NOW ADDITIONAL SEVERE WEATHER
POSSIBILITIES LOOK LOW AT LEAST THROUGH THE MIDDLE OF THE WEEK.
TEMPERATURES THROUGH THE WEEK REMAIN MILD... BUT MUGGY CONDITIONS WILL
LINGER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 63 77 63 / 60 70 70 40
HOBART OK 76 63 78 57 / 70 40 60 20
WICHITA FALLS TX 79 66 80 63 / 70 40 60 30
GAGE OK 75 59 78 51 / 50 50 60 20
PONCA CITY OK 81 63 77 63 / 50 70 70 50
DURANT OK 80 67 79 66 / 40 60 60 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH SUNDAY EVENING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH SUNDAY EVENING FOR TXZ083>090.
&&
$$
23/23/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
1043 AM CDT FRI MAY 8 2015
.DISCUSSION...
PERSISTENT CLOUD COVER APPEARS TO BE REDUCING THE SEVERE WEATHER
POTENTIAL SOMEWHAT ACROSS CENTRAL AND NORTHERN OKLAHOMA TODAY.
THAT DOES NOT SIGNIFICANTLY AFFECT THE GRIDDED FORECAST...BUT
THERE MAY BE SOME ADJUSTMENTS TO THE SEVERE WEATHER OUTLOOKS
LATER THIS MORNING.
THE SAME CLOUD COVER HAS SLOWED HEATING ACROSS MUCH OF
OKLAHOMA...AND WE WILL ADJUST THE HOURLY GRIDS ACCORDINGLY.
ADDITIONAL UPDATES MAY BE NEEDED THROUGH THE DAY AS THE EVOLUTION
OF THE CONVECTIVE SYSTEMS BECOMES MORE APPARENT.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT FRI MAY 8 2015/
DISCUSSION...
TODAY WILL BE ANOTHER RATHER COMPLICATED SITUATION WITH REGARDS TO
CONVECTION AND ATTENDANT SEVERE WEATHER THREAT... AS WELL AS
ADDITIONAL HEAVY... POSSIBLY FLOODING RAINFALL. WILL ALSO HAVE
SOME PATCHY FOG TO DEAL WITH FOR A WHILE THIS MORNING.
MANY OF THE MODELS DEPICT MORNING CONVECTION DEVELOPING AS LIFT
BEGINS TO OVERSPREAD THE AREA AHEAD OF A LEAD SHORTWAVE. HOWEVER
THE MODELS DIFFER IN THEIR PLACEMENT OF THIS CONVECTION THROUGH
THE MORNING HOURS. THEY ALSO DIFFER IN HOW TO HANDLE RESIDUAL LOW
LEVEL BOUNDARIES FROM OVERNIGHT CONVECTION. MAIN BOUNDARY THIS
MORNING SHOULD RESIDE TO OUR SOUTH... BUT WOULD EXPECT IT TO TRY
TO LIFT BACK TO THE NORTH AS SOUTHERLY LOW LEVEL FLOW INCREASING
LATER THIS MORNING.
LATEST NAM/GFS DEPICT BOUNDARY LIFTING BACK TO NEAR I-40 CORRIDOR
BY AFTN. FOLLOWING THIS SCENARIO... WHICH ALSO KEEPS MUCH OF THE
MORNING CONVECTION ACROSS NORTHERN HALF OF THE AREA...WOULD AID IN
REINFORCING SURFACE BOUNDARY SOMEWHERE NEAR OR SLIGHTLY SOUTH OF
THE I-40 CORRIDOR BY THIS AFTN... ALTHOUGH OTHER BOUNDARIES WILL
LIKELY BE IN PLACE ACROSS THE AREA. ALTHOUGH THIS WOULD LIMIT
INSTABILITY ACROSS MUCH OF NORTHERN INTO PARTS OF CENTRAL
OKLAHOMA... SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS WOULD REMAIN
IN THE MORE UNSTABLE ENVIRONMENT FOR THE AFTN INTO THE EVENING.
THIS WILL BE THE MORE LIKELY AREA FOR MORE SIGNIFICANT STORMS...
INCLUDING VERY LARGE HAIL... DAMAGING WINDS AND TORNADOES THIS
AFTN AND EVENING.
LATEST FEW RUNS OF HRRR GIVE A DIFFERENT SCENARIO THIS MORNING.
THIS MODEL HAS MORE OF A COMPLEX OF STORMS DEVELOPING AND MOVING
ACROSS THE SOUTHERN HALF OF OKLAHOMA AND THE RED RIVER VALLEY
DURING THE DAY. THIS WOULD LIKELY BE THE MAIN SHOW FOR THE DAY AND
ANY ATTENDANT SEVERE WOULD LIKELY BE ASSOCIATED WITH THIS COMPLEX
OF STORMS... MUCH LIKE WHAT OCCURRED ON THURSDAY. EITHER SCENARIO
WOULD SUGGEST THAT THE SOUTHERN HALF OF OKLAHOMA SOUTH INTO NORTH
TEXAS WOULD BE THE FAVORED LOCATIONS FOR MORE SIGNIFICANT SEVERE
STORMS.
THIS ACTIVITY SHOULD GRADUALLY WEAKEN AND MOVE EAST OF THE AREA
LATE TONIGHT. WE THEN SET THE STAGE FOR ANOTHER DAY OF SEVERE
WEATHER ON SATURDAY. MAIN UPPER TROUGH IS EXPECTED TO SWING OUT
INTO THE PLAINS BY SAT AFTN AND EVENING. MODELS ARE AGAIN SHOWING
SOME MORNING SHOWERS/STORMS DEVELOPING ACROSS WESTERN INTO CENTRAL
SECTIONS OF THE AREA AS LIFT BEGINS TO INFLUENCE THE AREA AHEAD OF
MAIN TROUGH. THINK THAT THIS SHOULD PROGRESS EAST QUICK ENOUGH
THAT ATMOSPHERE SHOULD RECOVER/DESTABILIZE ALONG AND EAST OF THE
DRYLINE BY SAT AFTN ACROSS THE EASTERN OK/TX PANHANDLES INTO
WESTERN PORTIONS OF OKLAHOMA. THE COMBINATION OF EXPECTED
INSTABILITY AND FAVORABLE WIND FIELDS ARE EXPECTED TO LEAD TO THE
DEVELOPMENT OF SUPERCELL THUNDERSTORMS IN THESE AREAS SAT AFTN
CAPABLE OF TORNADOES/VERY LARGE HAIL/DAMAGING WINDS. THESE STORMS
WILL THEN MOVE EAST AND NORTHEAST ACROSS WESTERN OKLAHOMA AND
PERHAPS WESTERN NORTH TEXAS TOWARD THE I-35 CORRIDOR DURING THE
EVENING HOURS.
THIS SYSTEM WILL SLOWLY LIFT NORTH AND EAST SATURDAY NIGHT INTO
SUNDAY. AS THIS OCCURS... A COLD FRONT WILL SLIP SOUTH INTO THE
AREA AND WILL AGAIN BE A FOCUS FOR THUNDERSTORMS... SOME SEVERE
SUNDAY AFTN MAINLY ALONG AND SOUTHEAST OF I-44.
ALL THROUGH THIS TIME WILL BE ADDING TO THE RAINFALL AMOUNTS AND
FLOODING WILL CONTINUE TO BE A CONCERN THROUGH MOTHER`S DAY
WEEKEND. WILL CONT WITH THE CURRENT FLOOD WATCH THAT GOES THROUGH
THE DAY ON SUNDAY.
SHOULD SEE A DAY OR TWO OF MORE TRANQUIL WEATHER TO BEGIN NEXT
WEEK BEFORE MOISTURE BEGINS TO PULL BACK NORTH AND PRECIP CHANCES
RETURN TO THE AREA. RIGHT NOW ADDITIONAL SEVERE WEATHER
POSSIBILITIES LOOK LOW AT LEAST THROUGH THE MIDDLE OF THE WEEK.
TEMPERATURES THROUGH THE WEEK REMAIN MILD... BUT MUGGY CONDITIONS WILL
LINGER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 78 63 77 63 / 60 70 70 40
HOBART OK 77 63 78 57 / 70 40 60 20
WICHITA FALLS TX 80 66 80 63 / 70 40 60 30
GAGE OK 76 59 78 51 / 50 50 60 20
PONCA CITY OK 79 63 77 63 / 50 70 70 50
DURANT OK 81 67 79 66 / 40 60 60 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH SUNDAY EVENING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH SUNDAY EVENING FOR TXZ083>090.
&&
$$
23/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
331 AM CDT FRI MAY 8 2015
.DISCUSSION...
TODAY WILL BE ANOTHER RATHER COMPLICATED SITUATION WITH REGARDS TO
CONVECTION AND ATTENDANT SEVERE WEATHER THREAT... AS WELL AS
ADDITIONAL HEAVY... POSSIBLY FLOODING RAINFALL. WILL ALSO HAVE
SOME PATCHY FOG TO DEAL WITH FOR A WHILE THIS MORNING.
MANY OF THE MODELS DEPICT MORNING CONVECTION DEVELOPING AS LIFT
BEGINS TO OVERSPREAD THE AREA AHEAD OF A LEAD SHORTWAVE. HOWEVER
THE MODELS DIFFER IN THEIR PLACEMENT OF THIS CONVECTION THROUGH
THE MORNING HOURS. THEY ALSO DIFFER IN HOW TO HANDLE RESIDUAL LOW
LEVEL BOUNDARIES FROM OVERNIGHT CONVECTION. MAIN BOUNDARY THIS
MORNING SHOULD RESIDE TO OUR SOUTH... BUT WOULD EXPECT IT TO TRY
TO LIFT BACK TO THE NORTH AS SOUTHERLY LOW LEVEL FLOW INCREASING
LATER THIS MORNING.
LATEST NAM/GFS DEPICT BOUNDARY LIFTING BACK TO NEAR I-40 CORRIDOR
BY AFTN. FOLLOWING THIS SCENARIO... WHICH ALSO KEEPS MUCH OF THE
MORNING CONVECTION ACROSS NORTHERN HALF OF THE AREA...WOULD AID IN
REINFORCING SURFACE BOUNDARY SOMEWHERE NEAR OR SLIGHTLY SOUTH OF
THE I-40 CORRIDOR BY THIS AFTN... ALTHOUGH OTHER BOUNDARIES WILL
LIKELY BE IN PLACE ACROSS THE AREA. ALTHOUGH THIS WOULD LIMIT
INSTABILITY ACROSS MUCH OF NORTHERN INTO PARTS OF CENTRAL
OKLAHOMA... SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS WOULD REMAIN
IN THE MORE UNSTABLE ENVIRONMENT FOR THE AFTN INTO THE EVENING.
THIS WILL BE THE MORE LIKELY AREA FOR MORE SIGNIFICANT STORMS...
INCLUDING VERY LARGE HAIL... DAMAGING WINDS AND TORNADOES THIS
AFTN AND EVENING.
LATEST FEW RUNS OF HRRR GIVE A DIFFERENT SCENARIO THIS MORNING.
THIS MODEL HAS MORE OF A COMPLEX OF STORMS DEVELOPING AND MOVING
ACROSS THE SOUTHERN HALF OF OKLAHOMA AND THE RED RIVER VALLEY
DURING THE DAY. THIS WOULD LIKELY BE THE MAIN SHOW FOR THE DAY AND
ANY ATTENDANT SEVERE WOULD LIKELY BE ASSOCIATED WITH THIS COMPLEX
OF STORMS... MUCH LIKE WHAT OCCURRED ON THURSDAY. EITHER SCENARIO
WOULD SUGGEST THAT THE SOUTHERN HALF OF OKLAHOMA SOUTH INTO NORTH
TEXAS WOULD BE THE FAVORED LOCATIONS FOR MORE SIGNIFICANT SEVERE
STORMS.
THIS ACTIVITY SHOULD GRADUALLY WEAKEN AND MOVE EAST OF THE AREA
LATE TONIGHT. WE THEN SET THE STAGE FOR ANOTHER DAY OF SEVERE
WEATHER ON SATURDAY. MAIN UPPER TROUGH IS EXPECTED TO SWING OUT
INTO THE PLAINS BY SAT AFTN AND EVENING. MODELS ARE AGAIN SHOWING
SOME MORNING SHOWERS/STORMS DEVELOPING ACROSS WESTERN INTO CENTRAL
SECTIONS OF THE AREA AS LIFT BEGINS TO INFLUENCE THE AREA AHEAD OF
MAIN TROUGH. THINK THAT THIS SHOULD PROGRESS EAST QUICK ENOUGH
THAT ATMOSPHERE SHOULD RECOVER/DESTABILIZE ALONG AND EAST OF THE
DRYLINE BY SAT AFTN ACROSS THE EASTERN OK/TX PANHANDLES INTO
WESTERN PORTIONS OF OKLAHOMA. THE COMBINATION OF EXPECTED
INSTABILITY AND FAVORABLE WIND FIELDS ARE EXPECTED TO LEAD TO THE
DEVELOPMENT OF SUPERCELL THUNDERSTORMS IN THESE AREAS SAT AFTN
CAPABLE OF TORNADOES/VERY LARGE HAIL/DAMAGING WINDS. THESE STORMS
WILL THEN MOVE EAST AND NORTHEAST ACROSS WESTERN OKLAHOMA AND
PERHAPS WESTERN NORTH TEXAS TOWARD THE I-35 CORRIDOR DURING THE
EVENING HOURS.
THIS SYSTEM WILL SLOWLY LIFT NORTH AND EAST SATURDAY NIGHT INTO
SUNDAY. AS THIS OCCURS... A COLD FRONT WILL SLIP SOUTH INTO THE
AREA AND WILL AGAIN BE A FOCUS FOR THUNDERSTORMS... SOME SEVERE
SUNDAY AFTN MAINLY ALONG AND SOUTHEAST OF I-44.
ALL THROUGH THIS TIME WILL BE ADDING TO THE RAINFALL AMOUNTS AND
FLOODING WILL CONTINUE TO BE A CONCERN THROUGH MOTHER`S DAY
WEEKEND. WILL CONT WITH THE CURRENT FLOOD WATCH THAT GOES THROUGH
THE DAY ON SUNDAY.
SHOULD SEE A DAY OR TWO OF MORE TRANQUIL WEATHER TO BEGIN NEXT
WEEK BEFORE MOISTURE BEGINS TO PULL BACK NORTH AND PRECIP CHANCES
RETURN TO THE AREA. RIGHT NOW ADDITIONAL SEVERE WEATHER
POSSIBILITIES LOOK LOW AT LEAST THROUGH THE MIDDLE OF THE WEEK.
TEMPERATURES THROUGH THE WEEK REMAIN MILD... BUT MUGGY CONDITIONS WILL
LINGER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 78 63 77 63 / 60 70 70 40
HOBART OK 77 63 78 57 / 70 40 60 20
WICHITA FALLS TX 80 66 80 63 / 70 40 60 30
GAGE OK 76 59 78 51 / 50 50 60 20
PONCA CITY OK 79 63 77 63 / 50 70 70 50
DURANT OK 81 67 79 66 / 40 60 60 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH SUNDAY EVENING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH SUNDAY EVENING FOR TXZ083>090.
&&
$$
84/30
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
110 AM EDT FRI MAY 8 2015
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL REMAIN ACROSS THE WESTERN
CAROLINAS OVERNIGHT AS SUBTROPICAL STORM ANA SLOWLY DRIFTS NORTHWARD
OFF THE SOUTHEAST COAST. ANA IS EXPECTED TO STALL JUST OFFSHORE
FRIDAY AND SATURDAY...AND THEN MOVE GRADUALLY NORTHWARD ALONG THE
NORTH CAROLINA COAST ON SUNDAY AND MONDAY. A COLD FRONT IS THEN
EXPECTED TO EVENTUALLY APPROACH THE AREA BY TUESDAY OR WEDNESDAY OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
0515 UTC UPDATE...WINDS WERE UPDATED TO INCLUDE THE LATEST NAM AND
ADJMAV GUIDANCE. SKY COVER WAS ADJUSTED PER SATELLITE IMAGERY. MINOR
ADJUSTMENTS WERE MADE TO TEMPERATURES BASED ON THE LATEST GUIDANCE.
1015 PM UPDATE...SKIES CLEARING AS ANTICIPATED DUE TO UPPER LEVEL
DRYING...THOUGH IT IS OCCURRING MORE RAPIDLY THAN EXPECTED. REVISED
SKY COVER GRIDS OVERNIGHT...MOST NOTABLY EAST OF THE BLUE RIDGE
WHERE IR TEMPS ARE WARMING FASTEST. TEMPS ARE CURRENTLY ON
TRACK...BUT GIVEN THE CLEARER SKIES COOLING MAY ACCELERATE. BLENDED
IN A BIT OF THE RAP TEMPS WHICH SEEMED TO KEEP TEMPS WARMER UNDER
THE CLOUDIER AREAS. STILL EXPECTING PATCHY FOG IN THE MORE FAVORED
AREAS NEAR THE BLUE RIDGE...NAMELY MORGANTON/LENOIR AREAS...AND IN
THE LITTLE TENN VALLEY.
PREVIOUS DISCUSSION...TONIGHT...THE DEVELOPING SUBTROPICAL (OR
TROPICAL) LOW WILL CONTINUE TO SPIN OFF THE SC COAST. OTHER THAN
PERIODS OF THICK CIRRUS OVC...SHUD BE A QUIET NIGHT. TEMPS WILL BE
SIMILAR TO LAST NIGHT...PERHAPS A CATEGORY OR TWO WARMER DUE TO
INCREASING CLOUDS.
FRIDAY...THE WX LOOKS ALMOST A CARBON COPY OF THURSDAY...WITH LITTLE
MOVEMENT OF THE LOW NEAR THE SC COAST. DEPENDING ON HOW MUCH
DEVELOPMENT THE LOW MAY ACQUIRE...THERE MAY BE MORE CLOUD COVER AND
A LITTLE MORE BREEZINESS. BUT OTHERWISE...EXPECT ANOTHER ROUND OF
GARDEN VARIETY SHWRS AND TSTMS IN THE NC MTNS...WITH TEMPS BACK INTO
THE 70S TO LWR 80S...AND LWR-MID 80S IN THE PIEDMONT. CANNOT RULE
OUT ONE OR TWO BANDS OF LIGHT SHWRS EMANATING FROM THE SUBTROPICAL
LOW...PIVOTING EAST TO WEST ACRS THE CHARLOTTE AREA. BUT STILL ONLY
A SLGT CHC POP SEEMS WARRANTED THERE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AS OF 230 PM THURSDAY...THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH
THE POSITION AND MOVEMENT OF THE DEVELOPING SUB TROPICAL LOW OFF THE
SERN COAST. THE LOW REMAINS NEARLY STATIONARY SAT THEN MOVES SLOWLY
TO THE SC COAST SUN. MOISTURE AND INSTABILITY GRADUALLY INCREASE
THRU THE PERIOD AS MOISTURE AND SPOKES OF VORTICITY SPIN AROUND THE
LOW AND ACROSS THE CWFA. THAT SAID...THE BEST CHC FOR PRECIP BOTH
DAYS REMAINS THE MTNS WHERE THE BEST INSTABILITY AND WEAK UPSLOPE
FLOW DEVELOP. CHC INCREASES OUTSIDE OF THE MTNS ON SUN AS THE MID
LEVEL SUBSIDENCE INVERSION WEAKENS ALLOWING AN INCREASE IN
INSTABILITY. THE PRECIP CHC STILL REMAINS MAINLY DIURNAL...
ESPECIALLY WEST OF I-77 WHERE INFLUENCES FROM THE LOW ARE WEAKER.
ISOLATED SHRA COULD LINGER THRU THE NITE EAST OF I-77. HIGHS WILL BE
ABOVE NORMAL EACH DAY...BUT HIGHER ACROSS THE WEST. LOWS WILL BE
AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...GUIDANCE IN PRETTY GOOD AGREEMENT. THE
COASTAL LOW MOVES NE ACROSS THE NC COAST MON AS A COLD FRONT
APPROACHES FROM THE WEST...THEN OFF SHORE TUE AS THE COLD FRONT
CROSSES THE AREA. THIS WILL BRING AN INCREASING CHC OF MAINLY
DIURNAL CONVECTION BOTH DAYS. TEMPS WILL REMAIN ABOVE NORMAL BOTH
DAYS. THE COLD STALLS SOUTH OF THE AREA WED AS HIGH PRESSURE MOVES
INTO A COLD AIR DAMMING CONFIGURATION...BUT FCST REMAINS DRY. TEMPS
WILL BE ABOVE NORMAL BUT COOLER THAN PREVIOUS DAYS. MOISTURE AND
PRECIP THEN RETURNS ACROSS THE AREA THE AS SLY LOW LEVEL FLOW
DEVELOPS OVER THE DAMMING HIGH. LOWS WILL COOL...BUT REMAIN ABOVE
NORMAL WHILE HIGHS FALL TO NEAR NORMAL.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
AT KCLT...VFR. GUIDANCE TRIES TO BRING A MOISTURE BAND ASSOCIATED
WITH SUBTROPICAL SYSTEM ANA TOWARD THE AREA SATURDAY
EVENING...BUT CONFIDENCE IS LOW ON ITS ARRIVAL AND THE AMOUNT OF
MOISTURE SURVIVING. WITH THAT IN MIND...THE TAF WILL BE
PRECIPITATION FREE. WINDS WILL FAVOR THE NE AS ANA SLOWLY MOVES
TOWARD THE SC COAST.
ELSEWHERE...MODEL GUIDANCE IS LEANING TOWARD AN MVFR DAYBREAK FOG
RESTRICTION AT KAVL...AND THIS WILL BE FEATURED IN THE TAF. MOISTURE
OVER THE MOUNTAINS MAY PERMIT A LOW VFR CIG TO FORM AT KAVL DURING
DAYTIME HEATING AND LIFT...AND A THUNDERSTORM IS POSSIBLE DURING THE
AFTERNOON. FOOTHILL SITES WILL BE IN DRY AIR BETWEEN TROPICAL SYSTEM
ANA AND THE MOUNTAINS...AND THEREFORE VFR. WINDS WILL FAVOR THE NE
AT FOOTHILLS SITES...AND NNW AT KAVL.
OUTLOOK...A MOIST AIR MASS WITH POSSIBLE UPSLOPE ENHANCEMENT ALONG
THE HIGH TERRAIN WILL SUPPORT DIURNAL SHRA/TSRA THROUGH THE
WEEKEND. ALTHOUGH RAIN CHANCES WILL BE MINIMAL OUTSIDE OF THE
MTNS...CANT RULE OUT LIGHT SHRA AS MOISTURE WRAPS AROUND SOUTHEAST
COASTAL LOW WITH LOW LEVEL CIGS ALSO A POSSIBILITY THIS WEEKEND AND
INTO THE START OF THE NEW WORK WEEK. A COLD FRONT APPROACH FROM THE
WEST ON MONDAY...ARRIVING ON TUESDAY...ACCOMPANIED BY
PRECIPITATION AND ASSOCIATED RESTRICTIONS.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-00Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 83% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...WIMBERLEY
NEAR TERM...ARK/JAT/WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
806 PM CDT SAT MAY 9 2015
.UPDATE...
MAIN UPDATE TO THE FORECAST WAS TO INCREASE PRECIP CHANCES ACROSS
WESTERN PORTIONS OF THE CWA WHERE A COMPLEX OF SHOWERS AND
THUNDERSTORMS WAS ONGOING. WHILE LARGE SCALE FORCING REMAINS
WEAK...CONTINUED CONVERGENCE DRIVEN BY SOUTHEASTERLY FLOW AHEAD
THE SYSTEM WILL AT LEAST MAINTAIN THIS COMPLEX FOR THE NEXT 1-2
HOURS...IF NOT LONGER. TEMPERATURES ACROSS THIS AREA WERE COOLER
THAN FORECAST AS WELL...THEREFORE...ADJUSTED TRENDS TO REFLECT
THIS THROUGH MIDNIGHT.
A VERY COMPLEX SURFACE PATTERN WILL CONTINUE THROUGH TOMORROW WITH SEVERAL
OUTFLOW BOUNDARIES LIKELY STREWN ACROSS THE CWA. PRECIP CHANCES
MAY NEED TO BE ADJUSTED ONCE MORE LATER THIS EVENING AS TRENDS
EVOLVE THROUGH THE NIGHT.
TVT
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT SAT MAY 9 2015/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 320 PM CDT SAT MAY 9 2015/
DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON PLACES A QUASI-
STATIONARY BOUNDARY OVER PORTIONS OF SOUTHERN MISSOURI AND BACK
INTO OKLAHOMA AND PORTIONS OF THE TEXAS/OKLAHOMA PANHANDLE.
SHOWERS AND THUNDERSTORM COVERAGE HAS DECREASED IN COVERAGE ACROSS
THE MID SOUTH THIS AFTERNOON AS THE ATMOSPHERE HAS STABILIZED
SOMEWHAT. A CLUSTER OF SHOWERS ARE LOCATED ACROSS PORTIONS OF
NORTH CENTRAL AND NORTHEAST ARKANSAS AS OF LATE THIS AFTERNOON.
TEMPERATURES AS OF 3 PM CDT ARE IN THE UPPER 70S TO LOWER 80S AT
MOST LOCATIONS.
WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES OVER THE PAST FEW
HOURS HAVE INDICATED ANOTHER MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS
DEVELOPED ACROSS OKLAHOMA AND THE RED RIVER VALLEY OF TEXAS.
WRF/GFS/ECMWF MODELS INDICATE THIS ACTIVITY SHOULD REMAIN MAINLY
WEST OF THE FORECAST AREA THIS EVENING. INTERESTINGLY ENOUGH...THE
19Z HRRR INDICATES CONVECTIVE ACTIVITY OVER NORTHEAST
TEXAS/EASTERN OKLAHOMA...AND SOUTHWEST ARKANSAS MAY SPREAD INTO
PORTIONS OF THE MID SOUTH ALONG AND WEST OF THE RIVER BY EARLY TO
MIDDLE EVENING. THIS HIGH RESOLUTION MODEL/S OUTPUT MAY BE TRYING
TO SUGGEST A COLD POOL DEVELOPING UPSTREAM AND BRINGING THE
CONVECTION INTO THE FORECAST AREA. WILL GO WITH CHANCE POPS ALONG
AND WEST OF THE MISSISSIPPI RIVER TONIGHT. EVENING SHIFT WILL
MONITOR MESOSCALE TRENDS AND ADJUST FORECAST AS NECESSARY
ESPECIALLY IF THE OUTLYING HRRR ENDS UP BEING THE CORRECT SHORT
TERM FORECAST SOLUTION.
SHORT TERM MODELS INDICATE SOUTHWEST FLOW ALOFT WILL REMAIN IN
PLACE ACROSS THE MID SOUTH ON SUNDAY WITH MOST IF NOT ALL SHOWERS
AND THUNDERSTORMS OCCURING UPSTREAM OF THE MID SOUTH.
CONSEQUENTLY...HAVE KEPT POPS ISOLATED AT BEST DURING THE DAY WITH
THE EXCEPTION OF EXTREME NORTHEAST MISSISSIPPI. ADDITIONAL SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND SPREAD INTO THE MID SOUTH
SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS INTO THE MID SOUTH.
THE BEST UPPER LEVEL FORCING AND FAVORABLE WINDS WILL MOVE
NORTHEAST OF THE FORECAST AREA BY MONDAY. SUFFICIENT
INSTABILITY...0-6 KM BULK SHEAR AND THE APPROACHING FRONT MAY BE
ENOUGH TO PRODUCE A CONDITIONAL THREAT FOR A FEW STRONG TO
PERHAPS SEVERE THUNDERSTORMS ACROSS THE MID SOUTH LATE SUNDAY
NIGHT INTO MONDAY.
THIS FRONT IS EXPECTED TO PUSH SOUTH OF THE FORECAST AREA BY
TUESDAY AFTERNOON/TUESDAY NIGHT AND BRING MAINLY RAIN FREE WEATHER
THROUGH WEDNESDAY NIGHT. SHOWER/THUNDERSTORM CHANCES WILL RETURN
LATE NEXT WEEK AS THE FRONT RETURNS BACK NORTH ACROSS THE MID
SOUTH.
CJC
.AVIATION...
00Z TAFS
SHRA OVER CENTRAL AR WILL CONTINUE TO LIFT NE THROUGH THE
EVENING. EARLIER RUNS OF THE HRRR MODEL SHOWED CELLS SOUTH OF LIT
ARRIVING TO THE MEM VCNTY AROUND 06Z...BUT MORE RECENT HRRR RUNS
APPEAR TO BETTER REFLECT ONGOING TREND OF THESE STORMS GRADUALLY
WEAKENING AS THEY MOVE OVER A MORE STABLE BOUNDARY LAYER. HAVE
DROPPED LATE EVENING TS MENTION AT MEM.
MAY SEE A SECOND BUMP IN SHRA/TSRA CHANCES BY 10Z AT JBR AND
NORTHERN MEM VCNTY...IF THE LAST OF THE CONVECTION LIFTING OUT OF
THE ARKLATEX CAN SURVIVE A TRIP ACROSS AR WITH THE AID OF A 30 TO
40 KT LOW LEVEL JET. NAM DOES NOT SHOW THIS OCCURRING AND CONFIDENCE
IS NOT HIGH WITH RESPECT TO OVERNIGHT SHRA/TSRA CHANCES. MAY PULL
THE 10Z VCTS MENTION AT MEM IN A FUTURE UPDATE.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
720 PM CDT SAT MAY 9 2015
.UPDATE...
RADAR IMAGERY THIS EVENING SHOWS NO ACTIVITY ACROSS THE MID
STATE...ALTHOUGH A FEW SHOWERS ARE SKIRTING THE EASTERN CWA BORDER
ON THE PLATEAU. OTHER THAN A LOW POP FOR THE EASTERN
PLATEAU...WILL REMOVE POPS ELSEWHERE UNTIL LATE TONIGHT WHEN MCS
OVER ARKANSAS ATTEMPTS TO HEAD THIS WAY PER LATEST HRRR RUNS.
OTHERWISE...ANOTHER WARM NIGHT EXPECTED WITH LOWS IN THE 60S.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 308 PM CDT SAT MAY 9 2015/
DISCUSSION...
AREA OF SHOWERS AND THUNDERSTORMS ATTEMPTED TO MOVE EAST AND INTO
MIDDLE TN EARLIER TODAY. THE ACTIVITY HAS FALLEN APART AS SUFFICIENT
LEVELS OF MOISTURE...INSTABILITY AND FORCING IS NOT IN PLACE.
ANOTHER AREA OF DEEP MOISTURE WILL PASS TO OUR NORTHWEST TONIGHT.
SOME OF THIS MOISTURE MAY REACH OUR WESTERN AREA AFTER MIDNIGHT. THE
BETTER UPPER DIVERGENCE WILL BE OFF TO THE NORTHWEST BUT OUR NW
COUNTIES COULD SEE SOME CONVECTION RETURN LATE.
ON SUNDAY...MOISTURE LEVELS DROP BACK DOWN AND ONLY A SLIGHT CHANCE
OF SHOWERS AND TSTMS WILL BE INCLUDED. THE BEST CHANCE WILL BE
ACROSS THE PLATEAU DURING THE MORNING.
SUNDAY NIGHT WILL FEATURE AN INCREASE IN MOISTURE TRANSPORT LATE.
SOUTHWESTERLY FLOW ALOFT WILL STIFFEN AS A FRONTAL BOUNDARY MOVES
INTO THE MS VALLEY AREA. THIS WILL SET THE STAGE FOR A BETTER
CHANCE OF SHOWERS AND TSTMS ON MONDAY AS THE FROPA OCCURS. STILL NOT
IMPRESSED WITH ANY ORGANIZED SEVERE POTENTIAL WITH THE MONDAY SYSTEM.
SYSTEM IS STILL EXPECTED TO ELONGATE W-E WHICH WILL MINIMIZE THE N-S
LINEAR FORCING THAT IS NEEDED. 850 MB FLOW WILL BE ABOUT 30 KTS.
CAPES MAY APPROACH ABOUT 1200 J/KG...SO ALL IN ALL...NOT REAL
IMPRESSIVE. QPF MODEL RETURN AVERAGES ONLY ABOUT A TENTH OF AN INCH.
FOR THE NEAR TERM TEMPS...WONT DRIFT MUCH FROM THE MAV. WILL
GENERALLY GO ABOVE BY ABOUT 1 DEGREE.
IN THE EXT FCST...LOOKS LIKE A DRY WINDOW FOR TUES THROUGH THU AS A
SFC HIGH BUILDS IN. THE PATTERN WILL THEN TURN WETTER BY THE
WEEKEND. THE FLOW PATTERN WILL BECOME MORE SOUTHWESTERLY WHICH WILL
BRING MOISTURE IN. ADDITIONALLY...A SERIES OF NORTHEASTWARD MOVING
IMPULSES WILL ACT AS THE CATALYST TO PRODUCE SOME MORE APPRECIABLE
RAINFALL. FOR THE TAIL END OF THE EXTENDED...POPS WILL REACH THE 50
TO PERHAPS 60 PERCENT LEVEL.
FOR THE EXT TEMPS...VALUES WILL COOL BACK DOWN TO NEAR SEASONAL WITH
THE SFC HIGH BUILDING IN. THEN...WARMER LOW TEMPS AS THE DEEPER
SOUTHERLY FLOW AND MOISTURE RETURNS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
650 PM CDT SAT MAY 9 2015
.UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 320 PM CDT SAT MAY 9 2015/
DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON PLACES A QUASI-
STATIONARY BOUNDARY OVER PORTIONS OF SOUTHERN MISSOURI AND BACK
INTO OKLAHOMA AND PORTIONS OF THE TEXAS/OKLAHOMA PANHANDLE.
SHOWERS AND THUNDERSTORM COVERAGE HAS DECREASED IN COVERAGE ACROSS
THE MID SOUTH THIS AFTERNOON AS THE ATMOSPHERE HAS STABILIZED
SOMEWHAT. A CLUSTER OF SHOWERS ARE LOCATED ACROSS PORTIONS OF
NORTH CENTRAL AND NORTHEAST ARKANSAS AS OF LATE THIS AFTERNOON.
TEMPERATURES AS OF 3 PM CDT ARE IN THE UPPER 70S TO LOWER 80S AT
MOST LOCATIONS.
WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES OVER THE PAST FEW
HOURS HAVE INDICATED ANOTHER MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS
DEVELOPED ACROSS OKLAHOMA AND THE RED RIVER VALLEY OF TEXAS.
WRF/GFS/ECMWF MODELS INDICATE THIS ACTIVITY SHOULD REMAIN MAINLY
WEST OF THE FORECAST AREA THIS EVENING. INTERESTINGLY ENOUGH...THE
19Z HRRR INDICATES CONVECTIVE ACTIVITY OVER NORTHEAST
TEXAS/EASTERN OKLAHOMA...AND SOUTHWEST ARKANSAS MAY SPREAD INTO
PORTIONS OF THE MID SOUTH ALONG AND WEST OF THE RIVER BY EARLY TO
MIDDLE EVENING. THIS HIGH RESOLUTION MODEL/S OUTPUT MAY BE TRYING
TO SUGGEST A COLD POOL DEVELOPING UPSTREAM AND BRINGING THE
CONVECTION INTO THE FORECAST AREA. WILL GO WITH CHANCE POPS ALONG
AND WEST OF THE MISSISSIPPI RIVER TONIGHT. EVENING SHIFT WILL
MONITOR MESOSCALE TRENDS AND ADJUST FORECAST AS NECESSARY
ESPECIALLY IF THE OUTLYING HRRR ENDS UP BEING THE CORRECT SHORT
TERM FORECAST SOLUTION.
SHORT TERM MODELS INDICATE SOUTHWEST FLOW ALOFT WILL REMAIN IN
PLACE ACROSS THE MID SOUTH ON SUNDAY WITH MOST IF NOT ALL SHOWERS
AND THUNDERSTORMS OCCURING UPSTREAM OF THE MID SOUTH.
CONSEQUENTLY...HAVE KEPT POPS ISOLATED AT BEST DURING THE DAY WITH
THE EXCEPTION OF EXTREME NORTHEAST MISSISSIPPI. ADDITIONAL SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND SPREAD INTO THE MID SOUTH
SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS INTO THE MID SOUTH.
THE BEST UPPER LEVEL FORCING AND FAVORABLE WINDS WILL MOVE
NORTHEAST OF THE FORECAST AREA BY MONDAY. SUFFICIENT
INSTABILITY...0-6 KM BULK SHEAR AND THE APPROACHING FRONT MAY BE
ENOUGH TO PRODUCE A CONDITIONAL THREAT FOR A FEW STRONG TO
PERHAPS SEVERE THUNDERSTORMS ACROSS THE MID SOUTH LATE SUNDAY
NIGHT INTO MONDAY.
THIS FRONT IS EXPECTED TO PUSH SOUTH OF THE FORECAST AREA BY
TUESDAY AFTERNOON/TUESDAY NIGHT AND BRING MAINLY RAIN FREE WEATHER
THROUGH WEDNESDAY NIGHT. SHOWER/THUNDERSTORM CHANCES WILL RETURN
LATE NEXT WEEK AS THE FRONT RETURNS BACK NORTH ACROSS THE MID
SOUTH.
CJC
&&
.AVIATION...
00Z TAFS
SHRA OVER CENTRAL AR WILL CONTINUE TO LIFT NE THROUGH THE
EVENING. EARLIER RUNS OF THE HRRR MODEL SHOWED CELLS SOUTH OF LIT
ARRIVING TO THE MEM VCNTY AROUND 06Z...BUT MORE RECENT HRRR RUNS
APPEAR TO BETTER REFLECT ONGOING TREND OF THESE STORMS GRADUALLY
WEAKENING AS THEY MOVE OVER A MORE STABLE BOUNDARY LAYER. HAVE
DROPPED LATE EVENING TS MENTION AT MEM.
MAY SEE A SECOND BUMP IN SHRA/TSRA CHANCES BY 10Z AT JBR AND
NORTHERN MEM VCNTY...IF THE LAST OF THE CONVECTION LIFTING OUT OF
THE ARKLATEX CAN SURVIVE A TRIP ACROSS AR WITH THE AID OF A 30 TO
40 KT LOW LEVEL JET. NAM DOES NOT SHOW THIS OCCURRING AND CONFIDENCE
IS NOT HIGH WITH RESPECT TO OVERNIGHT SHRA/TSRA CHANCES. MAY PULL
THE 10Z VCTS MENTION AT MEM IN A FUTURE UPDATE.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
327 PM CDT FRI MAY 8 2015
.DISCUSSION...
SOUTHERLY FLOW HAS RETURNED.,,PARTICULARLY TO OUR WEST WHERE CAP
EROSION AND DEEPER MOISTURE HAS RESULTED IN CONVECTIVE ACTIVITY.
MODELS IN AGREEMENT WITH SPREADING THE MOISTURE AXIS EASTWARD BUT
MOISTURE LEVELS WILL DECLINE. FURTHERMORE...OVERNIGHT UPPER
DIVERGENCE APPEARS TO BE MISSING FROM THE EQUATION. THUS...WILL
INCLUDE A 20 TO 40 PERCENT CHANCE OF SHOWERS AND TSTMS ACROSS
ROUGHLY THE WESTERN HALF OF THE AREA. THE HRRR IS LEANING TOWARD
HOLDING ONTO THE ACTIVITY A LITTLE LONGER...PARTICULARLY ACROSS FAR
WESTERN AREAS. OTW...MOSTLY CLOUDY THIS EVENING WEST...THEN PCLDY
AREA WIDE LATE.
ON SATURDAY...SHOWER AND TSTM CHANCES WILL INCREASE A LITTLE MORE AS
A WEAKENING SFC TROUGH MOVES ACROSS THE MID STATE. BETTER MOISTURE
AND CAPE VALUES WILL ALSO BE AT WORK. POPS WILL CONTINUE INTO SAT
NT. BUT AGAIN...THE UPPER DIVERGENT FIELDS AND MOISTURE DEPTH WILL
LIKELY NOT SUPPORT LATE NIGHT ACTIVITY.
ON SUNDAY...FAVORABLE CAPE TO CAP RATIOS WILL BE IN PLACE DURING THE
DAY. BUT...POPS AGAIN WILL BE LOW AS DYNAMICS LACK.
FOR THE NEAR TERM TEMPS...WILL GO CLOSE TO MOS...MAYBE A TOUCH
UNDER.
IN THE EXTENDED FCST...A COLD FRONT WILL BE ON APPROACH AND BRING A
BETTER CHANCE OF SHOWERS AND TSTMS FOR MONDAY. HOWEVER...A CLOSER
LOOK AT BOTH THE EURO AND GFS SOLUTIONS INDICATES THAT W-E BOUNDARY
ELONGATION WILL BE TAKING PLACE ALONG THE MAIN SFC LOW WAY UP ACROSS
THE WI AND MI AREAS. THIS WILL ACT TO REDUCE THE FAVORABLE STRONG
LLJ OVER OUR AREA. IN FACT...WE WILL SEE A WEAKER SOUTHWESTERLY FLOW
AT THE 850 MB LEVEL. THE STRONG N-S LINEAR CONVECTION IS NOT
INDICATED. FURTHERMORE...THE MID LEVEL JET WILL RESIDE WELL TO OUR
NORTHWEST AS WELL. THROW IN VERY LOW QPF RETURN AND THE CHANCE FOR A
WELL ORGANIZED SEVERE EVENT APPEAR TO BE VERY LOW AT THIS TIME. SO
FOR THE FCST...WILL KEEP A CHANCE OF SHOWERS AND TSTMS FOR MON AND
MON NIGHT.
TUESDAY AND WEDNESDAY...PREVAILING SFC HIGH WILL BRING A BIT OF A
COOL DOWN. UPPER PATTERN STILL SHOWS ELEVATED HEIGHTS SO NEAR TO
PERHAPS SLIGHTLY ABOVE NORMAL TEMPS.
BY THE END OF THE WEEK...UPPER LEVEL SOUTHWESTERLY FLOW WILL RETURN
AND BRING AN INCREASE IN MOISTURE AND INSTABILITY. ALONG WITH THAT
WILL BE A RETURN OF SHOWER AND TSTM CHANCES...BUT NO WELL ORGANIZED
FRONTS ARE INDICATED.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 65 87 66 89 / 20 30 20 30
CLARKSVILLE 64 85 65 87 / 30 40 20 30
CROSSVILLE 60 81 62 82 / 20 20 20 40
COLUMBIA 64 87 65 89 / 20 30 20 30
LAWRENCEBURG 63 88 64 87 / 20 20 20 20
WAVERLY 64 85 65 87 / 40 40 20 30
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
903 PM CDT SAT MAY 9 2015
.UPDATE...
HAVE REMOVED EVENING THUNDER MENTION FOR THE FAR ERN SLIVER OF
THE FCST AREA AS THAT THREAT HAS MOVED EAST OF THE REGION. TEMP
AND HUMIDITY FCST FOR THE ROLLING PLAINS AND FAR SERN PANHANDLE
PROBLEMATIC AS THE DRYLINE DID NOT QUITE GET ENTIRELY EAST OF THE
FCST AREA. CURRENTLY SEEING A BATTLE BETWEEN OUTFLOW-REINFORCED
MOIST AIRMASS MOVING EWD AND THE DRYLINE/SFC TROUGH. THIS TROUGH
SHOULD END UP MOVING TO THE EAST AGAIN AS THE UPPER LOW OVER
COLORADO MOVES ONTO THE PLAINS. HOWEVER UNTIL THEN...DEW POINTS
IN THE 60S WILL KEEP TEMPS THERE MILD UNTIL LATE TONIGHT AND MAY
SEE SOME LOW CLOUDS MOVE INTO THE CHILDRESS AREA AROUND MIDNIGHT
AND LINGER FOR SEVERAL HOURS BEFORE DRIER LOW LEVEL AIR CAN
FINALLY SWEEP THE MOISTURE EWD.
&&
.PREV DISCUSSION... /ISSUED 634 PM CDT SAT MAY 9 2015/
AVIATION...
DRYLINE HAS SHIFTED AS FAR EAST AS JUST OUTSIDE KCDS. GUSTY WSW
WINDS BEHIND SHOULD DIMINISH BY MID-EVENING WITH VFR CONDITIONS
EXPECTED AT BOTH KLBB AND KPVW. HOWEVER...EAST OF THE DRYLINE
VCTY KCDS RICH LOW LEVEL MOISTURE REMAINS. WITH A PUSH OF THE
DRYLINE A BIT TO THE WEST TONIGHT WOULD EXPECT MOISTURE TO BE
REINFORCED FROM DOWN THE RED RIVER VALLEY. THUS HAVE SIDED WITH
THE HI-RES HRRR AND INTRODUCED LOW CLOUDS IN THE KCDS TAF FROM
LATE EVENING TO AROUND SUNRISE SUNDAY. MAY VERY WELL END UP BEING
IFR THERE IF THESE CLOUDS DEVELOP...BUT HAVE STARTED JUST ABOVE
THAT CUTOFF ATTM.
PREV DISCUSSION... /ISSUED 534 PM CDT SAT MAY 9 2015/
SHORT TERM...
PACIFIC FRONT/DRYLINE HAS SURGED EAST THIS AFTERNOON AS EXPECTED AS
DRY SLOTTING HAS MOVED IN ALOFT ACROSS THE REGION. CORE OF THE UPPER
LOW CURRENTLY NEAR THE FOUR CORNERS REGION WILL LIFT TOWARD THE
FRONT RANGE INTO THIS EVENING WITH A SURFACE LOW HUGGING THE FRONT
RANGE/CENTRAL HIGH PLAINS. DEWPOINTS HAVE CRASHED INTO THE 20S/30S
ACROSS MUCH OF THE CAPROCK...BUT OUTFLOW BOUNDARIES FROM THIS
MORNING/S CONVECTION COUPLED WITH STOUT MOIST SOUTHEASTERLY FLOW
ACROSS THE BIG COUNTRY HAVE HUNG UP THE DRYLINE ON A LINE FROM LAKE
MACKENZIE TO ROARING SPRINGS TO HASKELL. HAVE LEFT A SLIGHT CHANCE
FOR STORMS IN THE FORECAST ALONG AND EAST OF HIGHWAY 83 AS SURFACE
CONVERGENCE ALONG THIS BOUNDARY MAY BE JUST ENOUGH TO INITIATE
ISOLATED DEVELOPMENT WHEN COUPLED WITH CONTINUED WEAK HEIGHT FALLS
ALOFT. THIS CHANCE WILL BE HIGHLY CONDITIONAL ON WHETHER ENOUGH
HEATING WILL BE ABLE TO OCCUR IN A WORKED OVER/COLD POOL PLAGUED
AIRMASS.
WILL CONTINUE TO SEE A FEW LOBES OF ADDITIONAL ENERGY ROUND THE BASE
OF THE UPPER LOW THROUGH EARLY SUNDAY...BUT DRIER AIR COURTESY OF
DOWNSLOPE SURFACE WINDS WILL KEEP STORMS MAINLY CONFINED EAST OF THE
FAR EASTERN EDGE OF THE ROLLING PLAINS. SUNDAY MORNING LOOKS TO
BRING THE NEXT/LAST APPRECIABLE ROUND OF UPPER ENERGY TOWARD WEST
TEXAS...SO WILL KEEP A MENTION SOUTHEAST OF A GUTHRIE TO ASPERMONT
LINE AS 40 DEGREE DEWPOINTS MAY BE ENOUGH TO SPARK A QUICK STORM.
OTHERWISE...BREEZY WEST/SOUTHWEST WINDS SHOULD ACCOMPANY
TEMPERATURES TOPPING OUT IN THE MID 70S NORTHWEST TO LOW 80S SOUTH
AND EAST UNDER MOSTLY CLEAR SKIES.
LONG TERM...
WE/LL SEE A BREAK IN OUR ACTIVE WEATHER PATTERN THROUGH MONDAY...BUT
THE CHANCE FOR SHOWERS AND T-STORMS WILL INCREASE AGAIN NEXT WEEK.
THE COLD FRONT WILL BE EXITING THE FORECAST AREA MONDAY MORNING WITH
BREEZY NORTHERLY WINDS DIMINISHING AND SWINGING AROUND TO THE E-SE
BY MONDAY EVENING. IT WILL BE ON THE COOL SIDE BEHIND THE FRONT
MONDAY WITH HIGHS MAINLY IN THE UPPER 60S AND LOWER 70S. SHORTWAVE
RIDGING WILL DEVELOP OVER WEST TEXAS TUESDAY DOWNSTREAM OF A UPPER
TROUGH MOVING ACROSS THE WEST COAST. INDICATIONS ARE THAT THIS
TROUGH WILL BE PROGRESSIVE AND MAY BEGIN TO AFFECT THE REGION BY
TUESDAY EVENING. THE NAM IS THE MOST BULLISH OF THE MODELS WITH THE
QPF FORECAST...GENERATING A SWATH OF RAIN COMING IN FORM THE SW TUES
AFTERNOON AND EVENING. THIS MAY BE OVERDONE GIVEN THAT IT WILL TAKE
SOME TIME FOR LOW-LEVEL MOISTURE TO RECHARGE AND THE ECMWF AND GFS
ARE SLOWER WITH THE LIFT. WE WILL MAINTAIN A CHANCE OF PRECIP IN THE
SW SPLNS...TAPERING DOWN FARTHER EAST TUESDAY EVENING AND
OVERNIGHT. THE GFS AND ECMWF STILL INDICATE THAT WED WILL BE THE
PRIMARY PERIOD FOR RAIN CHANCES WITH A WELL-DEVELOPED SHORTWAVE
OUT OF NM AND ACROSS WEST TEXAS...AT ROUGHLY THE SAME TIME DEEP
GULF MOISTURE IS MOVING BACK INTO THE AREA. PROGGED QPF AMOUNTS
ARE QUITE HIGH...WITH A SIMILAR APPEARANCE TO OUR LAST STRONGLY
FORCED CONVECTION MAY 5TH. HOWEVER...THIS IS STILL 5 DAYS OUT AND
WE MAY NOT SEE LIFT AND MOISTURE QUITE AS SYNCHRONIZED THIS TIME.
SHORTWAVE LIFTS NWD AWAY FROM THE AREA ON THURSDAY BUT THE UPPER
TROUGH TO OUR WEST WILL BE QUICK TO RELOAD AS NEXT ROUND OF
ENERGY DROPS INTO THE SW. THE EMCWF AND GFS BEGIN TO DIVERGE BY
THIS TIME AS THE ECMWF DROPS A UPPER LOW ALL THE WAY INTO SRN
CALIFORNIA WHILE THE GFS BREAKS THE ENERGY UP INTO SEVERAL PIECES
MOVING ACROSS THE GREAT BASIN AND 4-CORNERS REGIONS. EITHER WAY
.LOW-LEVEL MOISTURE SHOULD BE DRAWN WEST INTO ERN NM AND
PERTURBATIONS IN THE SWRLY FLOW OVER WTX SHOULD BE SUFFICIENT TO
SUPPORT AT LEAST SOME DIURNAL T- STORM DEVELOP EACH AFTN AND
EVENING FRI...SAT AND PERHAPS INTO SUNDAY JUST DEPENDING ON HOW
THE UPPER TROUGH/LOW ACROSS THE WEST EVOLVES.
FIRE WEATHER...
WARM...DRY AND BREEZY CONDITIONS WILL PERSIST THROUGH EARLY EVENING
ACROSS THE CAPROCK. OVERNIGHT MOISTURE RECOVERY WILL BE POOR AS
THE DRYLINE REMAINS TO THE EAST. SIMILAR CONDITIONS ARE EXPECTED
ACROSS THE ENTIRE FORECAST AREA ON SUNDAY. HOWEVER...THE FIRE
WEATHER CONCERNS WILL REMAIN LOW DUE TO THE RECENT WIDESPREAD WETTING
RAINS A GREENUP. A COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY MORNING BRINGING A PERIOD OF GUSTY NORTHERLY WINDS.
SEASONABLE COOL AND DRY CONDITIONS ARE EXPECTED MONDAY...WITH
MOISTURE LEVELS AND RAIN CHANCES ON THE INCREASE BY LATE TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 74 41 69 / 0 0 10 0
TULIA 48 74 44 69 / 0 0 10 0
PLAINVIEW 45 75 45 69 / 0 0 10 0
LEVELLAND 46 77 46 71 / 0 0 10 0
LUBBOCK 46 78 47 71 / 0 0 10 0
DENVER CITY 48 78 47 73 / 0 0 0 0
BROWNFIELD 48 79 48 73 / 0 0 10 0
CHILDRESS 59 81 51 71 / 0 0 10 0
SPUR 54 81 51 71 / 0 0 10 0
ASPERMONT 60 83 54 73 / 10 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
634 PM CDT SAT MAY 9 2015
.AVIATION...
DRYLINE HAS SHIFTED AS FAR EAST AS JUST OUTSIDE KCDS. GUSTY WSW
WINDS BEHIND SHOULD DIMINISH BY MID-EVENING WITH VFR CONDITIONS
EXPECTED AT BOTH KLBB AND KPVW. HOWEVER...EAST OF THE DRYLINE
VCTY KCDS RICH LOW LEVEL MOISTURE REMAINS. WITH A PUSH OF THE
DRYLINE A BIT TO THE WEST TONIGHT WOULD EXPECT MOISTURE TO BE
REINFORCED FROM DOWN THE RED RIVER VALLEY. THUS HAVE SIDED WITH
THE HI-RES HRRR AND INTRODUCED LOW CLOUDS IN THE KCDS TAF FROM
LATE EVENING TO AROUND SUNRISE SUNDAY. MAY VERY WELL END UP BEING
IFR THERE IF THESE CLOUDS DEVELOP...BUT HAVE STARTED JUST ABOVE
THAT CUTOFF ATTM.
&&
.PREV DISCUSSION... /ISSUED 534 PM CDT SAT MAY 9 2015/
SHORT TERM...
PACIFIC FRONT/DRYLINE HAS SURGED EAST THIS AFTERNOON AS EXPECTED AS
DRY SLOTTING HAS MOVED IN ALOFT ACROSS THE REGION. CORE OF THE UPPER
LOW CURRENTLY NEAR THE FOUR CORNERS REGION WILL LIFT TOWARD THE
FRONT RANGE INTO THIS EVENING WITH A SURFACE LOW HUGGING THE FRONT
RANGE/CENTRAL HIGH PLAINS. DEWPOINTS HAVE CRASHED INTO THE 20S/30S
ACROSS MUCH OF THE CAPROCK...BUT OUTFLOW BOUNDARIES FROM THIS
MORNING/S CONVECTION COUPLED WITH STOUT MOIST SOUTHEASTERLY FLOW
ACROSS THE BIG COUNTRY HAVE HUNG UP THE DRYLINE ON A LINE FROM LAKE
MACKENZIE TO ROARING SPRINGS TO HASKELL. HAVE LEFT A SLIGHT CHANCE
FOR STORMS IN THE FORECAST ALONG AND EAST OF HIGHWAY 83 AS SURFACE
CONVERGENCE ALONG THIS BOUNDARY MAY BE JUST ENOUGH TO INITIATE
ISOLATED DEVELOPMENT WHEN COUPLED WITH CONTINUED WEAK HEIGHT FALLS
ALOFT. THIS CHANCE WILL BE HIGHLY CONDITIONAL ON WHETHER ENOUGH
HEATING WILL BE ABLE TO OCCUR IN A WORKED OVER/COLD POOL PLAGUED
AIRMASS.
WILL CONTINUE TO SEE A FEW LOBES OF ADDITIONAL ENERGY ROUND THE BASE
OF THE UPPER LOW THROUGH EARLY SUNDAY...BUT DRIER AIR COURTESY OF
DOWNSLOPE SURFACE WINDS WILL KEEP STORMS MAINLY CONFINED EAST OF THE
FAR EASTERN EDGE OF THE ROLLING PLAINS. SUNDAY MORNING LOOKS TO
BRING THE NEXT/LAST APPRECIABLE ROUND OF UPPER ENERGY TOWARD WEST
TEXAS...SO WILL KEEP A MENTION SOUTHEAST OF A GUTHRIE TO ASPERMONT
LINE AS 40 DEGREE DEWPOINTS MAY BE ENOUGH TO SPARK A QUICK STORM.
OTHERWISE...BREEZY WEST/SOUTHWEST WINDS SHOULD ACCOMPANY
TEMPERATURES TOPPING OUT IN THE MID 70S NORTHWEST TO LOW 80S SOUTH
AND EAST UNDER MOSTLY CLEAR SKIES.
LONG TERM...
WE/LL SEE A BREAK IN OUR ACTIVE WEATHER PATTERN THROUGH MONDAY...BUT
THE CHANCE FOR SHOWERS AND T-STORMS WILL INCREASE AGAIN NEXT WEEK.
THE COLD FRONT WILL BE EXITING THE FORECAST AREA MONDAY MORNING WITH
BREEZY NORTHERLY WINDS DIMINISHING AND SWINGING AROUND TO THE E-SE
BY MONDAY EVENING. IT WILL BE ON THE COOL SIDE BEHIND THE FRONT
MONDAY WITH HIGHS MAINLY IN THE UPPER 60S AND LOWER 70S. SHORTWAVE
RIDGING WILL DEVELOP OVER WEST TEXAS TUESDAY DOWNSTREAM OF A UPPER
TROUGH MOVING ACROSS THE WEST COAST. INDICATIONS ARE THAT THIS
TROUGH WILL BE PROGRESSIVE AND MAY BEGIN TO AFFECT THE REGION BY
TUESDAY EVENING. THE NAM IS THE MOST BULLISH OF THE MODELS WITH THE
QPF FORECAST...GENERATING A SWATH OF RAIN COMING IN FORM THE SW TUES
AFTERNOON AND EVENING. THIS MAY BE OVERDONE GIVEN THAT IT WILL TAKE
SOME TIME FOR LOW-LEVEL MOISTURE TO RECHARGE AND THE ECMWF AND GFS
ARE SLOWER WITH THE LIFT. WE WILL MAINTAIN A CHANCE OF PRECIP IN THE
SW SPLNS...TAPERING DOWN FARTHER EAST TUESDAY EVENING AND
OVERNIGHT. THE GFS AND ECMWF STILL INDICATE THAT WED WILL BE THE
PRIMARY PERIOD FOR RAIN CHANCES WITH A WELL-DEVELOPED SHORTWAVE
OUT OF NM AND ACROSS WEST TEXAS...AT ROUGHLY THE SAME TIME DEEP
GULF MOISTURE IS MOVING BACK INTO THE AREA. PROGGED QPF AMOUNTS
ARE QUITE HIGH...WITH A SIMILAR APPEARANCE TO OUR LAST STRONGLY
FORCED CONVECTION MAY 5TH. HOWEVER...THIS IS STILL 5 DAYS OUT AND
WE MAY NOT SEE LIFT AND MOISTURE QUITE AS SYNCHRONIZED THIS TIME.
SHORTWAVE LIFTS NWD AWAY FROM THE AREA ON THURSDAY BUT THE UPPER
TROUGH TO OUR WEST WILL BE QUICK TO RELOAD AS NEXT ROUND OF
ENERGY DROPS INTO THE SW. THE EMCWF AND GFS BEGIN TO DIVERGE BY
THIS TIME AS THE ECMWF DROPS A UPPER LOW ALL THE WAY INTO SRN
CALIFORNIA WHILE THE GFS BREAKS THE ENERGY UP INTO SEVERAL PIECES
MOVING ACROSS THE GREAT BASIN AND 4-CORNERS REGIONS. EITHER WAY
..LOW-LEVEL MOISTURE SHOULD BE DRAWN WEST INTO ERN NM AND
PERTURBATIONS IN THE SWRLY FLOW OVER WTX SHOULD BE SUFFICIENT TO
SUPPORT AT LEAST SOME DIURNAL T- STORM DEVELOP EACH AFTN AND
EVENING FRI...SAT AND PERHAPS INTO SUNDAY JUST DEPENDING ON HOW
THE UPPER TROUGH/LOW ACROSS THE WEST EVOLVES.
FIRE WEATHER...
WARM...DRY AND BREEZY CONDITIONS WILL PERSIST THROUGH EARLY EVENING
ACROSS THE CAPROCK. OVERNIGHT MOISTURE RECOVERY WILL BE POOR AS
THE DRYLINE REMAINS TO THE EAST. SIMILAR CONDITIONS ARE EXPECTED
ACROSS THE ENTIRE FORECAST AREA ON SUNDAY. HOWEVER...THE FIRE
WEATHER CONCERNS WILL REMAIN LOW DUE TO THE RECENT WIDESPREAD WETTING
RAINS A GREENUP. A COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY MORNING BRINGING A PERIOD OF GUSTY NORTHERLY WINDS.
SEASONABLE COOL AND DRY CONDITIONS ARE EXPECTED MONDAY...WITH
MOISTURE LEVELS AND RAIN CHANCES ON THE INCREASE BY LATE TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 43 74 41 69 / 0 0 10 0
TULIA 45 74 44 69 / 0 0 10 0
PLAINVIEW 47 75 45 69 / 0 0 10 0
LEVELLAND 48 77 46 71 / 0 0 10 0
LUBBOCK 49 78 47 71 / 0 0 10 0
DENVER CITY 49 78 47 73 / 0 0 0 0
BROWNFIELD 50 79 48 73 / 0 0 10 0
CHILDRESS 55 81 51 71 / 10 0 10 0
SPUR 54 81 51 71 / 0 0 10 0
ASPERMONT 58 83 54 73 / 20 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1256 PM CDT FRI MAY 8 2015
.UPDATE...18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...MVFR CEILINGS STILL PREVAIL MIDDAY AT AUS/SAT/SSF/DRT
ALONG WITH SOME LOCATIONS EXPERIENCING MVFR VISIBILITIES IN HZ. A
GRADUAL RISE IN THE CEILINGS THROUGH THE AFTERNOON...BUT POSSIBLY
REMAINING IN MVFR RANGE ALONG THE I-35 CORRIDOR. IN ADDITION...
MID LEVEL FORCING IS GENERATING ELEVATED SHRAS WEST AND SOUTHWEST
OF THE I-35 CORRIDOR...WHICH ARE MOVING NORTHEAST. THESE HAVE THE
POTENTIAL TO IMPACT AUS/SAT/SSF THROUGH THE AFTERNOON...WITH TEMPO
INCLUDED IN AUS/SAT/SSF TAFS THROUGH 21Z. POTENTIAL FOR DEEPER
CONVECTION TO DEVELOP 21Z-00Z ALONG AND EAST OF THE I-35 AS WELL
AS WEST OF THE RIO GRANDE. VCTS INCLUDED IN I-35 CORRIDOR TAFS
AFTER 21Z AND AT DRT AFTER 00Z.
LOWER MVFR CEILINGS RE-DEVELOPING THIS EVENING AT AUS/SAT/SSF AND
IFR CEILINGS OVERNIGHT. MVFR CEILINGS AT DRT DEVELOPING OVERNIGHT
AND INTO IFR RANGE BY 12Z SAT.
&&
.PREV DISCUSSION... /ISSUED 1043 AM CDT FRI MAY 8 2015/
UPDATE...
12Z HAND ANALYSIS GIVES A GOOD PICTURE OF WHAT IS CURRENTLY
HAPPENING ACROSS THE REGION AND AN OVERALL IDEA OF WHAT WE CAN
EXPECT TODAY. AT THE SURFACE...A LOW IS CENTERED NEAR MIDLAND
WITH THE TROUGH AXIS EXTENDING TO THE NORTHEAST TOWARDS WICHITA
FALLS. IT IS IN THIS GENERAL CORRIDOR THAT MOST SURFACE
CONVERGENCE AND ENHANCED LIFT WILL BE LOCATED FOR SURFACE BASED
CONVECTION. AT 700 AND 500 MB A DEEP UPPER LOW IS LOCATED NEAR
SOUTHERN CALIFORNIA WITH SOUTHWEST FLOW ACROSS TEXAS AND 700-500
MB LAPSE RATES ARE STEEPEST IN A CORRIDOR FROM DRT TO AMA. A QUICK
LOOK AT THE KDRT 12Z RAOB SHOWS A STOUT CAP AROUND 800 MB...BUT
MODEL ANALYSIS SHOWS THE CAP WEAKENS THE FARTHER EAST YOU GO. WHAT
THIS SHOULD EQUATE TO IS FOR CONTINUED ELEVATED ACTIVITY CURRENTLY
BEGINNING IN MEXICO TO MOVE EAST OVER OUR WESTERN COUNTIES LATER
THIS MORNING. WITH THE STEEP LEVEL LAPSE RATES...THERE IS A CHANCE
THERE COULD BE A STRONG THUNDERSTORM CAPABLE OF PRODUCING HAIL IF
ANY ELEVATED STORM IS ABLE TO REALLY TAP INTO THE LAPSE RATES. AS
THE ACTIVITY SPREADS EAST THIS AFTERNOON AND ENCOUNTERS AN
ENVIRONMENT MORE FAVORABLE FOR SURFACE BASED CONVECTION...WE COULD
SEE SOME DEEPER CONVECTION WITH HEAVIER RAINFALL. THIS WOULD
MAINLY BE EAST OF THE INTERSTATE 35/37 CORRIDORS. IF THIS WERE TO
OCCUR...LOCALLY HEAVY RAINFALL WOULD BE THE MAIN HAZARD BUT THERE
IS A THREAT FOR SEVERE CONVECTION AS WELL. RE-WORKED THE POP GRIDS
TO CONVEY THE LATEST THINKING.
PREV DISCUSSION... /ISSUED 433 AM CDT FRI MAY 8 2015/
SHORT TERM (TODAY THROUGH SATURDAY)...
MAIN HIGHLIGHT FOR TODAY WILL BE THE STRONG TO SEVERE STORM
POTENTIAL WEST OF THE I-35 CORRIDOR TOWARDS THE HILL
COUNTRY...EDWARDS PLATEAU AND THE RIO GRANDE PLAINS LATE THIS
AFTERNOON INTO THE EVENING. OVERALL CONFIDENCE IN CONVECTIVE
EVOLUTION IS MEDIUM GIVEN WIDE ASSORTMENT OF HI-RES GUIDANCE.
ANOTHER ROUND OF STRONG TO SEVERE STORMS WILL ALSO BE POSSIBLE
SATURDAY AFTERNOON AND EVENING.
FOR TODAY...THE WELL ADVERTISED CLOSED H5 LOW OVER SOUTHERN CA
WILL SHIFT EAST THROUGH THE AFTERNOON AND ALONG WITH EMBEDDED
IMPULSES STREAMING OUT OF NORTH MEXICO WILL AID IN A H5-H3 WIND
BELT INCREASE TOWARDS 50 TO 70KT RESPECTIVELY. WHILE THE BEST
FORCING AND DRYLINE BULGE WILL BE NORTH OF THE REGION...MODEST
INSTABILITY NEARING 3000 J/KG WITH A WEAK CAP AND IMPRESSIVE
VERTICAL TOTALS /29-31C/ SHOULD AT LEAST SUPPORT SOME ROBUST
UPDRAFTS. LARGE HAIL TO THE SIZE OF GOLF BALLS AND DAMAGING WINDS
TO 60 MPH WILL BE HAZARDS OF THESE STORMS. THE HRRR HAS BEEN
INCONSISTENT DURING THE OVERNIGHT PERIOD ALONG WITH THE ARW/NMM
THAT WERE ALSO HAVING DIFFICULTY RESOLVING STORMS YESTERDAY AT
THIS TIME. HAVE NOT PLACED MUCH STOCK IN THE OVER-DONE ARW/NMM
WITH SLIGHT WEIGHT TOWARDS HRRR. YET...EVEN IT DOES NOT READILY
SEEM TO FIT ENVIRONMENT CONCEPTUAL MODEL FOR THIS AFTERNOON. FEEL
SIMILAR TO YESTERDAY...CLOUDS WILL STICK AROUND LONGER ALONG I-35
AND EAST WITH MORE CLEARING WITH GROWING AND STRONGER
DESTABILIZATION OUT WEST. GFS DOES PROG A WEAK S/WV TO SHIFT OVER
THE RIO GRANDE THROUGH THE AFTERNOON BUT DO NOT SEE IT CREATING
STRATIFORM PRECIP AS THE HRRR SUGGESTS. GIVEN GFS/NAM SOUNDING
PROFILES SUPPORTING MORE OF A CONVECTIVE MODE...FEEL A MULTI-CELL
OR UPGROWTH INTO SOME LINEAR LINE SEGMENT COULD BE POSSIBLE OUT
WEST AND SHIFT NORTHEAST INTO THE HILL COUNTRY AND THEN NORTH OF
THE REGION. SPC SSEO AND NCAR ENSEMBLES ARE ALSO INCONSISTENT
AMONG THE MEMBERS. THE OVERALL SIGNAL DEPICTS INITIAL DEVELOPMENT
OUT WEST LATE AFTERNOON WITH CONSOLIDATION ACTUALLY NEAR THE 35
CORRIDOR AND NEAR SAN ANTONIO. WHILE POSSIBLE...FEEL MORE
SUPPORTIVE AREA WILL BE NORTH AND WEST. SOME ADDITIONAL TSTORM
ACTIVITY WILL BE POSSIBLE THROUGH SATURDAY MORNING WITH CELLS
POSSIBLY CONTINUING NE OUT OF MEXICO BUT OVERALL COVERAGE SHOULD
DECREASE.
BY SATURDAY AFTERNOON...THE DRYLINE WILL HAVE SHIFTED FARTHER EAST
INTO THE REGION AND INCREASE STRONG TO SEVERE STORM POTENTIAL
FARTHER EAST THAN TODAY. A DECREASE IN STORM POTENTIAL WILL ALSO
OCCUR BEHIND THE DRYLINE FOR FAR WESTERN AREAS. NEAR 2000-2500
J/KG CAPE VALUES AND 45-50 KT 0-6KM SHEAR SHOULD ALLOW FOR ANOTHER
ROUND OF STORMS THAT COULD AGAIN CONTAIN HAIL AND STRONG WINDS.
0-3KM HELICITY VALUES PER GFS MAY APPROACH 200-250 M2/S2 AND WITH
0-1KM SRH NEAR 150 MS/S2...STORMS THAT DO DEVELOP COULD ROTATE AND
A TORNADO CAN NOT BE FULLY RULED OUT. AGAIN...THE WINDOW FOR
STRONGEST STORMS WILL LATE AFTERNOON THROUGH THE EVENING FOR AREAS
ALONG AND WEST OF US HIGHWAY 83. CONVECTIVE TRENDS WILL MORPH FROM
STRONGER CONVECTION TOWARDS MORE STRATIFORM THROUGH THE NIGHT INTO
SUNDAY MORNING NEAR THE HILL COUNTRY AND HEAVY RAIN WILL BE OF
CONCERN. SEE LONG TERM BELOW FOR CONTINUED MENTION OF THIS IMPACT
PERIOD.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...
QUITE UNSETTLED PATTERN WILL CONTINUE THROUGH THE WEEKEND AND ALL
OF NEXT WEEK WITH LIKELY MULTIPLE ROUNDS OF SHOWERS AND STORMS
BRINGING ABOVE NORMAL RAINFALL AMOUNTS. BOTH GFS/EC MODELS AGREE
WIDESPREAD TOTAL ACCUMULATIONS OF 3-5 INCHES WITH LOCALLY HIGHER
AMOUNTS TO 6-7"+ COULD BE POSSIBLE THROUGH THE END OF THE WEEK.
ELEVATED RIVER/CREEKS AND FLASH FLOODING COULD OCCUR IF CERTAIN
RAIN CLUSTERS DEVELOP JUST RIGHT.
FOR SATURDAY NIGHT INTO SUNDAY...THE AREA REMAINS IN DEEP SW FLOW
ALOFT AS ANOTHER DEEP TROUGH SPOKE PIVOTS ACROSS NORTH
TEXAS...ACTING TO ENHANCE DIVERGENCE ALOFT. PWATS REMAIN HIGH
/1.5-1.7"/ AND WILL SUPPORT LOCALIZED HEAVY DOWNPOURS THROUGH THE
DAY AND EVENING. HEAVIEST RAINFALL COULD OCCUR ACROSS HILL COUNTRY
AND POINTS NORTH TO NE AND COULD INCLUDE AUSTIN METRO. SOME
STRONG TO SEVERE STORMS COULD BE POSSIBLE EAST OF I-35 BUT
OVERNIGHT ACTIVITY WILL PLAY A LARGE ROLE IN AFTERNOON
DEVELOPMENT.
A SURFACE BOUNDARY IS STILL EXPECTED TO SHIFT SOUTH TOWARDS THE
REGION BY MONDAY INTO TUESDAY BUT THIS WILL ONLY SERVE AS ANOTHER
FOCUS FOR PRECIPITATION DEVELOPMENT AS SW FLOW AND TROUGHING
CONTINUE OVER THE REGION WITH AMPLE MOISTURE IN PLACE THROUGH THE
ATMOSPHERIC COLUMN. EARLY NEXT WEEK WILL NEED TO BE WATCHED
CLOSELY FOR ANY FLASH FLOOD WATCHES POSSIBLY BEING NEEDED. BY
TUESDAY...THE FIRST LONG WAVE TROUGH WILL EXIT THE GREAT PLAINS
BUT THE ACTIVE SOUTHERN JET STREAM BRANCH CONTINUES AND IS EVEN
REPLACED BY ANOTHER LARGE TROUGH ON THE WEST COAST WEDNESDAY AND
YET ANOTHER BY LATE NEXT WEEK. PLEASE STAY UP TO DATE WITH THE
LATEST THROUGH THE WEEK AS QUICKLY ACCUMULATING RAINFALL TOTALS
COULD LEAD TO FLOODING IMPACTS. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 73 86 73 82 69 / 30 40 30 60 70
AUSTIN BERGSTROM INTL AIRPORT 73 86 73 84 70 / 40 40 30 60 70
NEW BRAUNFELS MUNI AIRPORT 72 87 73 84 70 / 30 40 20 50 60
BURNET MUNI AIRPORT 70 83 70 80 67 / 30 50 50 70 70
DEL RIO INTL AIRPORT 72 92 71 87 67 / 40 20 20 40 30
GEORGETOWN MUNI AIRPORT 72 83 72 81 68 / 30 50 30 70 70
HONDO MUNI AIRPORT 72 88 74 86 70 / 40 40 20 50 60
SAN MARCOS MUNI AIRPORT 73 86 73 84 69 / 30 40 20 50 70
LA GRANGE - FAYETTE REGIONAL 74 86 75 85 72 / 40 30 20 40 60
SAN ANTONIO INTL AIRPORT 73 87 73 85 70 / 30 40 20 50 60
STINSON MUNI AIRPORT 73 88 74 85 71 / 30 30 20 50 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...29
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1245 PM CDT FRI MAY 8 2015
.DISCUSSION...
SEE THE 18Z AVIATION BELOW.
40
&&
.AVIATION...
AN UPPER LEVEL SHORTWAVE TROUGH WAS GENERATING A FEW SHOWERS AND
ISOLATED THUNDERSTORMS FROM KIAH NORTHWARD AT 1730Z. ANOTHER
ROUND WILL BE POSSIBLE LATER THIS AFTERNOON WITH THE BEST CHANCES
FOR THUNDER ACROSS KCLL AND KUTS. THE HIGH RESOLUTION MODELS THEN
FORECAST ANOTHER WINDOW FOR SHOWERS BETWEEN ABOUT 09Z AND 15Z.
OTHERWISE...MVFR POSSIBLE OVER MOST SITES BY 04Z TONIGHT...WITH
IFR CONDITIONS PROBABLE AT KGLS.
40
&&
.PREV DISCUSSION... /ISSUED 952 AM CDT FRI MAY 8 2015/
DISCUSSION...
MAIN CHANGES FOR THE MORNING UPDATE WERE TO BUMP UP POPS ACROSS
THE REGION LATE IN THE DAY AND THIS EVENING AS W/V IMAGERY SHOWING
IMPULSE APPROACHING BIG BEND AREA MAY TAKE A TRACK MORE FAVORABLE
IN PRODUCING PRECIP ACROSS THE AREA AS HRRR AND TX TECH WRF
DEPICTS. WILL KEEP AN EYE ON TRENDS. ALSO EXTENDED THE CAUTION
FLAGS FOR THE 20-60NM GULF WATERS. OTHERWISE...REST OF THE
PACKAGE LEFT ABOUT THE SAME. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 86 73 86 74 85 / 40 40 30 30 50
HOUSTON (IAH) 86 74 85 75 86 / 20 40 20 20 40
GALVESTON (GLS) 83 76 83 76 83 / 20 40 20 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 5 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...47
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
952 AM CDT FRI MAY 8 2015
.DISCUSSION...
MAIN CHANGES FOR THE MORNING UPDATE WERE TO BUMP UP POPS ACROSS
THE REGION LATE IN THE DAY AND THIS EVENING AS W/V IMAGERY SHOWING
IMPULSE APPROACHING BIG BEND AREA MAY TAKE A TRACK MORE FAVORABLE
IN PRODUCING PRECIP ACROSS THE AREA AS HRRR AND TX TECH WRF
DEPICTS. WILL KEEP AN EYE ON TRENDS. ALSO EXTENDED THE CAUTION
FLAGS FOR THE 20-60NM GULF WATERS. OTHERWISE...REST OF THE
PACKAGE LEFT ABOUT THE SAME. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 86 73 86 74 85 / 40 40 30 30 50
HOUSTON (IAH) 86 74 85 75 86 / 20 40 20 20 40
GALVESTON (GLS) 83 76 83 76 83 / 20 40 20 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 5 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
647 AM CDT FRI MAY 8 2015
.AVIATION...
NOT MUCH CHANGE FROM PREVIOUS FORECAST. MVFR/IFR CIGS HAVE SPREAD
ACROSS THE REGION AND SHOULD REMAIN THAT WAY FOR THE NEXT FEW
HOURS. SLOW IMPROVEMENT THIS MORNING TO VFR BY AROUND NOON. THERE
IS A SLIGHT CHANCE FOR LIGHT RAIN THIS MORNING...BUT PROBABILITY
IS TOO LOW TO INCLUDE IN THE TAFS. IF THERE IS ANY RAIN IT WILL
NOT CHANGE FLYING CATEGORY. BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING. SOUTHEASTERLY FLOW
WILL CONTINUE TONIGHT AND LOW CIGS SHOULD REFORM DROPPING CIGS TO
MVFR AND IFR OVERNIGHT AGAIN.
&&
.PREV DISCUSSION... /ISSUED 433 AM CDT FRI MAY 8 2015/
SHORT TERM (TODAY THROUGH SATURDAY)...
MAIN HIGHLIGHT FOR TODAY WILL BE THE STRONG TO SEVERE STORM
POTENTIAL WEST OF THE I-35 CORRIDOR TOWARDS THE HILL
COUNTRY...EDWARDS PLATEAU AND THE RIO GRANDE PLAINS LATE THIS
AFTERNOON INTO THE EVENING. OVERALL CONFIDENCE IN CONVECTIVE
EVOLUTION IS MEDIUM GIVEN WIDE ASSORTMENT OF HI-RES GUIDANCE.
ANOTHER ROUND OF STRONG TO SEVERE STORMS WILL ALSO BE POSSIBLE
SATURDAY AFTERNOON AND EVENING.
FOR TODAY...THE WELL ADVERTISED CLOSED H5 LOW OVER SOUTHERN CA
WILL SHIFT EAST THROUGH THE AFTERNOON AND ALONG WITH EMBEDDED
IMPULSES STREAMING OUT OF NORTH MEXICO WILL AID IN A H5-H3 WIND
BELT INCREASE TOWARDS 50 TO 70KT RESPECTIVELY. WHILE THE BEST
FORCING AND DRYLINE BULGE WILL BE NORTH OF THE REGION...MODEST
INSTABILITY NEARING 3000 J/KG WITH A WEAK CAP AND IMPRESSIVE
VERTICAL TOTALS /29-31C/ SHOULD AT LEAST SUPPORT SOME ROBUST
UPDRAFTS. LARGE HAIL TO THE SIZE OF GOLF BALLS AND DAMAGING WINDS
TO 60 MPH WILL BE HAZARDS OF THESE STORMS. THE HRRR HAS BEEN
INCONSISTENT DURING THE OVERNIGHT PERIOD ALONG WITH THE ARW/NMM
THAT WERE ALSO HAVING DIFFICULTY RESOLVING STORMS YESTERDAY AT
THIS TIME. HAVE NOT PLACED MUCH STOCK IN THE OVER-DONE ARW/NMM
WITH SLIGHT WEIGHT TOWARDS HRRR. YET...EVEN IT DOES NOT READILY
SEEM TO FIT ENVIRONMENT CONCEPTUAL MODEL FOR THIS AFTERNOON. FEEL
SIMILAR TO YESTERDAY...CLOUDS WILL STICK AROUND LONGER ALONG I-35
AND EAST WITH MORE CLEARING WITH GROWING AND STRONGER
DESTABILIZATION OUT WEST. GFS DOES PROG A WEAK S/WV TO SHIFT OVER
THE RIO GRANDE THROUGH THE AFTERNOON BUT DO NOT SEE IT CREATING
STRATIFORM PRECIP AS THE HRRR SUGGESTS. GIVEN GFS/NAM SOUNDING
PROFILES SUPPORTING MORE OF A CONVECTIVE MODE...FEEL A MULTI-CELL
OR UPGROWTH INTO SOME LINEAR LINE SEGMENT COULD BE POSSIBLE OUT
WEST AND SHIFT NORTHEAST INTO THE HILL COUNTRY AND THEN NORTH OF
THE REGION. SPC SSEO AND NCAR ENSEMBLES ARE ALSO INCONSISTENT
AMONG THE MEMBERS. THE OVERALL SIGNAL DEPICTS INITIAL DEVELOPMENT
OUT WEST LATE AFTERNOON WITH CONSOLIDATION ACTUALLY NEAR THE 35
CORRIDOR AND NEAR SAN ANTONIO. WHILE POSSIBLE...FEEL MORE
SUPPORTIVE AREA WILL BE NORTH AND WEST. SOME ADDITIONAL TSTORM
ACTIVITY WILL BE POSSIBLE THROUGH SATURDAY MORNING WITH CELLS
POSSIBLY CONTINUING NE OUT OF MEXICO BUT OVERALL COVERAGE SHOULD
DECREASE.
BY SATURDAY AFTERNOON...THE DRYLINE WILL HAVE SHIFTED FARTHER EAST
INTO THE REGION AND INCREASE STRONG TO SEVERE STORM POTENTIAL
FARTHER EAST THAN TODAY. A DECREASE IN STORM POTENTIAL WILL ALSO
OCCUR BEHIND THE DRYLINE FOR FAR WESTERN AREAS. NEAR 2000-2500
J/KG CAPE VALUES AND 45-50 KT 0-6KM SHEAR SHOULD ALLOW FOR ANOTHER
ROUND OF STORMS THAT COULD AGAIN CONTAIN HAIL AND STRONG WINDS.
0-3KM HELICITY VALUES PER GFS MAY APPROACH 200-250 M2/S2 AND WITH
0-1KM SRH NEAR 150 MS/S2...STORMS THAT DO DEVELOP COULD ROTATE AND
A TORNADO CAN NOT BE FULLY RULED OUT. AGAIN...THE WINDOW FOR
STRONGEST STORMS WILL LATE AFTERNOON THROUGH THE EVENING FOR AREAS
ALONG AND WEST OF US HIGHWAY 83. CONVECTIVE TRENDS WILL MORPH FROM
STRONGER CONVECTION TOWARDS MORE STRATIFORM THROUGH THE NIGHT INTO
SUNDAY MORNING NEAR THE HILL COUNTRY AND HEAVY RAIN WILL BE OF
CONCERN. SEE LONG TERM BELOW FOR CONTINUED MENTION OF THIS IMPACT
PERIOD.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...
QUITE UNSETTLED PATTERN WILL CONTINUE THROUGH THE WEEKEND AND ALL
OF NEXT WEEK WITH LIKELY MULTIPLE ROUNDS OF SHOWERS AND STORMS
BRINGING ABOVE NORMAL RAINFALL AMOUNTS. BOTH GFS/EC MODELS AGREE
WIDESPREAD TOTAL ACCUMULATIONS OF 3-5 INCHES WITH LOCALLY HIGHER
AMOUNTS TO 6-7"+ COULD BE POSSIBLE THROUGH THE END OF THE WEEK.
ELEVATED RIVER/CREEKS AND FLASH FLOODING COULD OCCUR IF CERTAIN
RAIN CLUSTERS DEVELOP JUST RIGHT.
FOR SATURDAY NIGHT INTO SUNDAY...THE AREA REMAINS IN DEEP SW FLOW
ALOFT AS ANOTHER DEEP TROUGH SPOKE PIVOTS ACROSS NORTH
TEXAS...ACTING TO ENHANCE DIVERGENCE ALOFT. PWATS REMAIN HIGH
/1.5-1.7"/ AND WILL SUPPORT LOCALIZED HEAVY DOWNPOURS THROUGH THE
DAY AND EVENING. HEAVIEST RAINFALL COULD OCCUR ACROSS HILL COUNTRY
AND POINTS NORTH TO NE AND COULD INCLUDE AUSTIN METRO. SOME
STRONG TO SEVERE STORMS COULD BE POSSIBLE EAST OF I-35 BUT
OVERNIGHT ACTIVITY WILL PLAY A LARGE ROLE IN AFTERNOON
DEVELOPMENT.
A SURFACE BOUNDARY IS STILL EXPECTED TO SHIFT SOUTH TOWARDS THE
REGION BY MONDAY INTO TUESDAY BUT THIS WILL ONLY SERVE AS ANOTHER
FOCUS FOR PRECIPITATION DEVELOPMENT AS SW FLOW AND TROUGHING
CONTINUE OVER THE REGION WITH AMPLE MOISTURE IN PLACE THROUGH THE
ATMOSPHERIC COLUMN. EARLY NEXT WEEK WILL NEED TO BE WATCHED
CLOSELY FOR ANY FLASH FLOOD WATCHES POSSIBLY BEING NEEDED. BY
TUESDAY...THE FIRST LONG WAVE TROUGH WILL EXIT THE GREAT PLAINS
BUT THE ACTIVE SOUTHERN JET STREAM BRANCH CONTINUES AND IS EVEN
REPLACED BY ANOTHER LARGE TROUGH ON THE WEST COAST WEDNESDAY AND
YET ANOTHER BY LATE NEXT WEEK. PLEASE STAY UP TO DATE WITH THE
LATEST THROUGH THE WEEK AS QUICKLY ACCUMULATING RAINFALL TOTALS
COULD LEAD TO FLOODING IMPACTS. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 85 72 86 73 83 / 40 30 40 30 60
AUSTIN BERGSTROM INTL AIRPORT 85 73 87 73 84 / 40 30 40 30 60
NEW BRAUNFELS MUNI AIRPORT 85 71 87 73 84 / 30 30 40 20 50
BURNET MUNI AIRPORT 83 70 83 70 80 / 50 30 50 50 70
DEL RIO INTL AIRPORT 91 72 92 72 88 / 30 40 20 20 40
GEORGETOWN MUNI AIRPORT 83 72 84 72 82 / 40 30 50 30 70
HONDO MUNI AIRPORT 88 71 88 73 86 / 30 40 40 20 50
SAN MARCOS MUNI AIRPORT 86 72 87 73 83 / 30 30 40 20 50
LA GRANGE - FAYETTE REGIONAL 86 75 86 75 85 / 30 30 30 20 40
SAN ANTONIO INTL AIRPORT 86 72 87 73 84 / 30 30 40 20 50
STINSON MUNI AIRPORT 87 72 88 73 85 / 30 30 30 20 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...15
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
433 AM CDT FRI MAY 8 2015
.SHORT TERM (TODAY THROUGH SATURDAY)...
MAIN HIGHLIGHT FOR TODAY WILL BE THE STRONG TO SEVERE STORM
POTENTIAL WEST OF THE I-35 CORRIDOR TOWARDS THE HILL
COUNTRY...EDWARDS PLATEAU AND THE RIO GRANDE PLAINS LATE THIS
AFTERNOON INTO THE EVENING. OVERALL CONFIDENCE IN CONVECTIVE
EVOLUTION IS MEDIUM GIVEN WIDE ASSORTMENT OF HI-RES GUIDANCE.
ANOTHER ROUND OF STRONG TO SEVERE STORMS WILL ALSO BE POSSIBLE
SATURDAY AFTERNOON AND EVENING.
FOR TODAY...THE WELL ADVERTISED CLOSED H5 LOW OVER SOUTHERN CA
WILL SHIFT EAST THROUGH THE AFTERNOON AND ALONG WITH EMBEDDED
IMPULSES STREAMING OUT OF NORTH MEXICO WILL AID IN A H5-H3 WIND
BELT INCREASE TOWARDS 50 TO 70KT RESPECTIVELY. WHILE THE BEST
FORCING AND DRYLINE BULGE WILL BE NORTH OF THE REGION...MODEST
INSTABILITY NEARING 3000 J/KG WITH A WEAK CAP AND IMPRESSIVE
VERTICAL TOTALS /29-31C/ SHOULD AT LEAST SUPPORT SOME ROBUST
UPDRAFTS. LARGE HAIL TO THE SIZE OF GOLF BALLS AND DAMAGING WINDS
TO 60 MPH WILL BE HAZARDS OF THESE STORMS. THE HRRR HAS BEEN
INCONSISTENT DURING THE OVERNIGHT PERIOD ALONG WITH THE ARW/NMM
THAT WERE ALSO HAVING DIFFICULTY RESOLVING STORMS YESTERDAY AT
THIS TIME. HAVE NOT PLACED MUCH STOCK IN THE OVER-DONE ARW/NMM
WITH SLIGHT WEIGHT TOWARDS HRRR. YET...EVEN IT DOES NOT READILY
SEEM TO FIT ENVIRONMENT CONCEPTUAL MODEL FOR THIS AFTERNOON. FEEL
SIMILAR TO YESTERDAY...CLOUDS WILL STICK AROUND LONGER ALONG I-35
AND EAST WITH MORE CLEARING WITH GROWING AND STRONGER
DESTABILIZATION OUT WEST. GFS DOES PROG A WEAK S/WV TO SHIFT OVER
THE RIO GRANDE THROUGH THE AFTERNOON BUT DO NOT SEE IT CREATING
STRATIFORM PRECIP AS THE HRRR SUGGESTS. GIVEN GFS/NAM SOUNDING
PROFILES SUPPORTING MORE OF A CONVECTIVE MODE...FEEL A MULTI-CELL
OR UPGROWTH INTO SOME LINEAR LINE SEGMENT COULD BE POSSIBLE OUT
WEST AND SHIFT NORTHEAST INTO THE HILL COUNTRY AND THEN NORTH OF
THE REGION. SPC SSEO AND NCAR ENSEMBLES ARE ALSO INCONSISTENT
AMONG THE MEMBERS. THE OVERALL SIGNAL DEPICTS INITIAL DEVELOPMENT
OUT WEST LATE AFTERNOON WITH CONSOLIDATION ACTUALLY NEAR THE 35
CORRIDOR AND NEAR SAN ANTONIO. WHILE POSSIBLE...FEEL MORE
SUPPORTIVE AREA WILL BE NORTH AND WEST. SOME ADDITIONAL TSTORM
ACTIVITY WILL BE POSSIBLE THROUGH SATURDAY MORNING WITH CELLS
POSSIBLY CONTINUING NE OUT OF MEXICO BUT OVERALL COVERAGE SHOULD
DECREASE.
BY SATURDAY AFTERNOON...THE DRYLINE WILL HAVE SHIFTED FARTHER EAST
INTO THE REGION AND INCREASE STRONG TO SEVERE STORM POTENTIAL
FARTHER EAST THAN TODAY. A DECREASE IN STORM POTENTIAL WILL ALSO
OCCUR BEHIND THE DRYLINE FOR FAR WESTERN AREAS. NEAR 2000-2500
J/KG CAPE VALUES AND 45-50 KT 0-6KM SHEAR SHOULD ALLOW FOR ANOTHER
ROUND OF STORMS THAT COULD AGAIN CONTAIN HAIL AND STRONG WINDS.
0-3KM HELICITY VALUES PER GFS MAY APPROACH 200-250 M2/S2 AND WITH
0-1KM SRH NEAR 150 MS/S2...STORMS THAT DO DEVELOP COULD ROTATE AND
A TORNADO CAN NOT BE FULLY RULED OUT. AGAIN...THE WINDOW FOR
STRONGEST STORMS WILL LATE AFTERNOON THROUGH THE EVENING FOR AREAS
ALONG AND WEST OF US HIGHWAY 83. CONVECTIVE TRENDS WILL MORPH FROM
STRONGER CONVECTION TOWARDS MORE STRATIFORM THROUGH THE NIGHT INTO
SUNDAY MORNING NEAR THE HILL COUNTRY AND HEAVY RAIN WILL BE OF
CONCERN. SEE LONG TERM BELOW FOR CONTINUED MENTION OF THIS IMPACT
PERIOD.
&&
.LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...
QUITE UNSETTLED PATTERN WILL CONTINUE THROUGH THE WEEKEND AND ALL
OF NEXT WEEK WITH LIKELY MULTIPLE ROUNDS OF SHOWERS AND STORMS
BRINGING ABOVE NORMAL RAINFALL AMOUNTS. BOTH GFS/EC MODELS AGREE
WIDESPREAD TOTAL ACCUMULATIONS OF 3-5 INCHES WITH LOCALLY HIGHER
AMOUNTS TO 6-7"+ COULD BE POSSIBLE THROUGH THE END OF THE WEEK.
ELEVATED RIVER/CREEKS AND FLASH FLOODING COULD OCCUR IF CERTAIN
RAIN CLUSTERS DEVELOP JUST RIGHT.
FOR SATURDAY NIGHT INTO SUNDAY...THE AREA REMAINS IN DEEP SW FLOW
ALOFT AS ANOTHER DEEP TROUGH SPOKE PIVOTS ACROSS NORTH
TEXAS...ACTING TO ENHANCE DIVERGENCE ALOFT. PWATS REMAIN HIGH
/1.5-1.7"/ AND WILL SUPPORT LOCALIZED HEAVY DOWNPOURS THROUGH THE
DAY AND EVENING. HEAVIEST RAINFALL COULD OCCUR ACROSS HILL COUNTRY
AND POINTS NORTH TO NE AND COULD INCLUDE AUSTIN METRO. SOME
STRONG TO SEVERE STORMS COULD BE POSSIBLE EAST OF I-35 BUT
OVERNIGHT ACTIVITY WILL PLAY A LARGE ROLE IN AFTERNOON
DEVELOPMENT.
A SURFACE BOUNDARY IS STILL EXPECTED TO SHIFT SOUTH TOWARDS THE
REGION BY MONDAY INTO TUESDAY BUT THIS WILL ONLY SERVE AS ANOTHER
FOCUS FOR PRECIPITATION DEVELOPMENT AS SW FLOW AND TROUGHING
CONTINUE OVER THE REGION WITH AMPLE MOISTURE IN PLACE THROUGH THE
ATMOSPHERIC COLUMN. EARLY NEXT WEEK WILL NEED TO BE WATCHED
CLOSELY FOR ANY FLASH FLOOD WATCHES POSSIBLY BEING NEEDED. BY
TUESDAY...THE FIRST LONG WAVE TROUGH WILL EXIT THE GREAT PLAINS
BUT THE ACTIVE SOUTHERN JET STREAM BRANCH CONTINUES AND IS EVEN
REPLACED BY ANOTHER LARGE TROUGH ON THE WEST COAST WEDNESDAY AND
YET ANOTHER BY LATE NEXT WEEK. PLEASE STAY UP TO DATE WITH THE
LATEST THROUGH THE WEEK AS QUICKLY ACCUMULATING RAINFALL TOTALS
COULD LEAD TO FLOODING IMPACTS. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 85 72 86 73 83 / 40 30 40 30 60
AUSTIN BERGSTROM INTL AIRPORT 85 73 87 73 84 / 40 30 40 30 60
NEW BRAUNFELS MUNI AIRPORT 85 71 87 73 84 / 30 30 40 20 50
BURNET MUNI AIRPORT 83 70 83 70 80 / 50 30 50 50 70
DEL RIO INTL AIRPORT 91 72 92 72 88 / 30 40 20 20 40
GEORGETOWN MUNI AIRPORT 83 72 84 72 82 / 40 30 50 30 70
HONDO MUNI AIRPORT 88 71 88 73 86 / 30 40 40 20 50
SAN MARCOS MUNI AIRPORT 86 72 87 73 83 / 30 30 40 20 50
LA GRANGE - FAYETTE REGIONAL 86 75 86 75 85 / 30 30 30 20 40
SAN ANTONIO INTL AIRPORT 86 72 87 73 84 / 30 30 40 20 50
STINSON MUNI AIRPORT 87 72 88 73 85 / 30 30 30 20 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...15
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
325 AM EDT FRI MAY 8 2015
.SYNOPSIS...
UPPER LEVEL HIGH PRESSURE WILL REMAIN IN PLACE TODAY INTO
SATURDAY...RESULTING IN CONTINUED WARM TEMPERATURES TO START THE
WEEKEND. SUBTROPICAL STORM ANA WILL DRIFT SLOWLY NORTHWARD TOWARD
THE COAST OF THE CAROLINAS LATER IN THE WEEKEND BEFORE PASSING
EAST OF THE AREA EARLY NEXT WEEK. A COLD FRONT WILL MOVE EAST
ACROSS THE AREA DURING TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT FRIDAY...
PERSISTENCE FORECAST CONTINUES THROUGH TONIGHT WITH UPPER LEVEL RIDGING
OVERHEAD BEING UNDERCUT TO SOME DEGREE OVER THE WEST VIA LOW LEVEL
WEAKNESS EXTENDING NW FROM ANA OFF THE SE COAST. THIS WILL AGAIN ALLOW
FOR PREDOMINANT EASTERLY FLOW RESULTING IN AN AXIS OF CONVERGENCE
ACROSS THE FAR WEST TODAY AND OVERALL SUBSIDENCE IN THE EAST PER DRIER
ONSHORE FLOW. GUIDANCE AGAIN SHOWING DECENT INSTABILITY WESTERN THIRD
THIS AFTERNOON ALTHOUGH SWATH OF HIGHER CAPES LOOKS TO SHIFT WEST OF
THE AREA LATER IN THE DAY AS A CORRIDOR OF SUBSIDENCE TO THE NORTH OF
ANA SWINGS WESTBOUND. THIS SEEN VIA THE LATEST 85H THETA-E PROGS WHICH
HAVE THE AXIS OF HIGHER VALUES JUST TO THE WEST BUT STILL ENOUGH OF A
GRADIENT WESTERN PERIMETER TO SUPPORT AT LEAST SCATTERED SLOW MOVING
CONVECTION. MOST MODELS IN LINE WITH AT LEAST A SHOTGUN TYPE PATTERN OF
SHRA/TSRA WITH ENSEMBLES SUPPORTING THE BEST COVERAGE OVER SE WEST VA
AS WELL AS THE NW NORTH CAROLINA MOUNTAINS WHERE AIDED BY DIFFERENTIAL
HEATING TO SOME DEGREE. MORE ISOLATED NATURE POP UP SHRA POSSIBLE
EAST TO THE BLUE RIDGE BUT APPEARS MOST COVERAGE FROM THE WESTERN
NEW RIVER VALLEY AND POINTS WEST THIS AFTERNOON CLOSER TO THE
RESIDUAL DEEPER MOISTURE AXIS. THUS BUMPED UP POPS TO HIGHER
CHANCE IN SPOTS OVER THE FAR WEST WHILE LEAVING AREAS EAST OF THE
BLUE RIDGE DRY GIVEN DEEPER MOISTURE WITH ANA STILL WELL SOUTH.
OTRW SIMILAR TEMPS TO THOSE SEEN THE LAST COUPLE OF DAYS WITH
HIGHS UPPER 70S- LOW 80S WITH MORE SUN EAST AND PC WEST AFTER
EARLY FOG/LOW CLOUDS.
ANY SHRA SHOULD FADE BY SUNSET GIVEN LACK OF SUPPORT AND BETTER
SUBSIDENCE SPILLING WESTWARD OVERNIGHT. SOME MODELS DO SHOW A GRADUAL
INCREASE IN PWATS OVER THE SE LATE AS PERHAPS A LEADING BAND OF SHRA
STARTS TO EJECT FARTHER NW FROM ANA. HOWEVER GIVEN DRY AIR THINKING
ONLY SOME INCREASE IN CLOUDS SE THIRD LATE WITH PC TO MOSTLY CLEAR ELSW
OVERNIGHT. LOW TEMPS AGAIN MOSTLY IN THE 50S TO LOW 60S WITH SOME
DROPOFF IN DEWPOINTS IN ALL BUT THE SE WHERE MOISTURE ADVECTION WILL BE
PICKING UP LATE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
THERE ARE TO KEY PLAYERS IN THE SHORT TERM FORECAST: THE SLOWLY
APPROACHING FRONTAL SYSTEM/UPPER TROUGH TO THE WEST AND
SUBTROPICAL STORM ANA. (SEE THE LATEST ADVISORY FROM NHC).
ON THE 200 AM EDT ADVISORY...THE CENTER OF SUBTROPICAL STORM
ANA WAS LOCATED NEAR LATITUDE 31.5 NORTH, LONGITUDE 77.7 WEST.
THE STORM WAS MOVING TOWARD THE NORTH-NORTHWEST NEAR 2 MPH (4 KM/H).
A TURN TOWARD THE NORTHWEST WITH A SLIGHT INCREASE IN FORWARD SPEED
IS EXPECTED OVER THE NEXT 48 HOURS. MAXIMUM SUSTAINED WINDS ARE NEAR
45 MPH (75 KM/H) WITH HIGHER GUSTS.
WITHOUT ANY TRACK CHANGES...ANA IS EXPECTED TO LANDFALL INTO THE
CAROLINAS POSSIBLY AS A TROPICAL STORM AROUND LATER SUN INTO MON.
THE 00Z GFS AND 00Z ECMWF ARE CLOSEST TO THE 03Z NHC ADVISORY WITH
THE 00Z NAM FARTHEST NORTH OF THE NHC TRACK. INITIAL...OUR FORECAST
AREA WILL BE LOCATED A SUBSIDENCE ZONE WITH LIMITED INSTABILITY
BETWEEN THE TROUGH TO THE WEST AND ANA TO OUR EAST.
FOR THIS WEEKEND ANTICIPATE TWO MAIN AREAS OF PRECIPITATION...
DIURNALLY DRIVEN SHOWERS AND ISOLATED THUNDERSTORMS WESTERN
MOUNTAINS WHERE INSOLATION WILL BE GREATER ALLOWING FOR BETTER
DIFFERENTIAL HEATING IN THE MOUNTAINOUS TERRAIN...WITH SOME DYNAMIC
FORCING FROM THE APPROACHING FRONT IN THE WEST...AND BANDS OF
RAIN/SHOWERS IN THE EAST ASSOCIATED WITH THE OUTER PERIPHERY OF THE
TROPICAL SYSTEM. WILL HOLD ONTO SOME ISOLATED POPS IN BETWEEN THE
TWO PRIMARY AREAS...ACROSS THE BLUE RIDGE AND INTO THE SHENANDOAH
VALLEY...POSSIBLY INDUCED BY OUTER SPIRALING BANDS OF THE TROPICAL
SYSTEM.
IN GENERAL...HIGH TEMPERATURES DURING THE PERIOD WILL RANGE FROM THE
MID 70S IN THE MOUNTAINS TO THE LOWER 80S IN THE PIEDMONT. LOW
TEMPERATURES WILL RANGE FROM THE UPPER 50S TO THE LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 350 PM EDT THURSDAY...
DURING THIS TIME FRAME...THERE APPEARS TO BE SOME BONAFIDE
MOVEMENT AND BREAK DOWN OF THE UPPER RIDGE SANDWICHED BETWEEN THE
SLOWLY EASTWARD PROGRESSING WESTERN/CENTRAL U.S. TROUGH AND THE
TROPICAL/SUBTROPICAL SYSTEM OFF THE EAST COAST. THE TROPICAL SYSTEM
SHOULD BEGIN AN ACCELERATED NORTHEASTWARD MOVEMENT OFF THE VA COAST
AS THE UPPER TROUGH PROGRESSES INTO THE OHIO VALLEY.
HOWEVER...INDICATIONS ARE THAT THE UPPER TROUGH WILL BEGIN TO SHEAR
OUT...WITH THE MAIN DYNAMICS MOVING MORE INTO OH AND THE NORTHEAST
U.S. MONDAY STILL APPEARS TO BE THE BEST DAY FOR WIDESPREAD
CONVECTION ACROSS THE CWA...ESPECIALLY IN THE WEST. THERE WILL
LIKELY BE SOME LINGERING SUBSIDENCE ACROSS EASTERN AREAS ON THE BACK
SIDE OF THE TROPICAL/SUBTROPICAL SYSTEM...WHICH MAKES IT
QUESTIONABLE AS TO HOW MUCH CONVECTION WILL SPREAD EAST OF THE BLUE
RIDGE AND TO WHAT LEVEL OF INTENSITY. ALL MODELS INDICATE THAT THE
BEST THREAT FOR CONVECTION...AND ANY THREAT OF STRONG TO
SEVERE...SHOULD BE MOSTLY WEST OF THE BLUE RIDGE MONDAY.
BY TUESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT A FRONT WILL
PUSH THROUGH AT LEAST THE NORTHWEST HALF OF THE REGION AND THE
TROPICAL SYSTEM WILL MOVE WELL OFF THE COAST. A DRIER AIR MASS
SHOULD BEGIN TO SPREAD INTO THE NORTHWEST HALF OF THE CWA...BUT
PERHAPS NOT AS QUICKLY AS THE GFS WOULD SUGGEST. WILL HOLD ONTO
CHANCE POPS FOR SHOWERS/THUNDERSTORMS ACROSS THE SOUTHEAST HALF INTO
TUE AFTERNOON...THEN DRY OUT ALL AREAS FOR WED. BY THU...A FAMILIAR
WEDGE PATTERN BEGINS TO SETUP WITH POTENTIAL OVERRUNNING AS A
DISTURBANCE RIDES AROUND THE WEST SIDE OF A BUILDING SUBTROPICAL
RIDGE ACROSS THE SOUTHEAST STATES. WILL HOLD OFF ON ANY MENTION OF
PRECIPITATION UNTIL THU.
TEMPERATURES WILL TREND FROM ABOVE NORMAL TUESDAY TO NEAR TO
SLIGHTLY BELOW NORMAL BY WED. THE BIGGEST TEMPERATURE CHANGE SHOULD
BE IN THE MORNING LOWS WITH DRIER AIR AND MORE EFFECTIVE RADIATIONAL
COOLING...ESPECIALLY ACROSS THE MOUNTAINS.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM EDT FRIDAY...
APPEARS MAINLY VFR CONDITIONS OUTSIDE OF ANY LATE NIGHT OR PRE-
DAWN FOG/STRATO-CU TO PREVAIL INTO EARLY FRIDAY MORNING. EXPECT
MAINLY CLEAR SKIES TO HELP TEMPS DROP OFF CLOSER TO CURRENT
DEWPOINTS ESPCLY IN THE VALLEYS AND OUT EAST WHERE ALREADY SEEING
SOME FOG DEVELOPMENT TAKE SHAPE. THUS WILL BEEF UP COVERAGE TO
INCLUDE A TEMPO OF MORE IFR FOG AROUND KLWB AND PERHAPS KBCB/KLYH.
COULD EVEN BE A BIT OF FOG AROUND KROA RIGHT BEFORE DAYBREAK BUT
MOSTLY BRIEF AND HIGH END MVFR AT WORSE.
FOR FRIDAY...EXPECT SCT/BKN CIRRUS/CS THANKS TO THE LOW PRESSURE
OFF THE CAROLINA COAST. HEATING WILL AGAIN LEAD TO MORE CU
DEVELOPMENT ESPCLY MOUNTAINS WHERE A PERIOD OF VFR CIGS
POSSIBLE...MAINLY WEST OF KBCB. HOWEVER LESS INSTABILITY FOR
FRIDAY AFTERNOON...AND THEREFORE EXPECT CONVECTION TO BE MORE
WIDELY SCATTERED...MAINLY ALONG THE MOUNTAINS WEST OF THE NEW
RIVER VALLEY INTO THE MOUNTAIN EMPIRE AND NC MTNS. SINCE LATEST
GUIDANCE AGAIN PEGS THE KLWB VICINITY FOR BEST SHRA/TSRA
CHANCES...ADDED IN A VCTS MENTION THERE PER LATEST HRRR OUTPUT.
OTHERWISE WILL LEAVE OUT ANY CONVECTION MENTION AND KEEP THINGS
VFR FRIDAY AFTERNOON UNDER EASTERLY FLOW.
ISOLATED AFTERNOON AND EARLY EVENING SHOWERS AND STORMS WILL
AGAIN BE POSSIBLE MAINLY FROM KLWB TO KBLF...AND PERHAPS AROUND
KDAN BY SATURDAY. OTHERWISE TREND FOR THE AXIS OF BEST COVERAGE
WILL SLOWLY WORK ITS WAY WEST OF THE REGION. THUS EXPECTING MAINLY
VFR EXCEPT FOR SOME LATE NIGHT AND EARLY MORNING PATCHY LIGHT FOG
AS WELL AS PATCHY MVFR CLOUDS FRIDAY NIGHT INTO SATURDAY.
FORECAST CONFIDENCE SATURDAY NIGHT INTO TUESDAY REMAINS LOW.
MODEL GUIDANCE IS STILL SHOWING A DECENT AMOUNT OF VARIABILITY IN
THEIR SOLUTIONS REGARDING THE ROUTE OF NEWLY FORMED SUBTROPICAL
STORM ANA. HOWEVER THE LATEST FORECAST FROM NHC HAS THE SYSTEM
TRACKING INLAND OVER EASTERN NORTH CAROLINA MONDAY AND WELL TO THE
EAST OF THE REGION BY EARLY TUESDAY. ACCORDINGLY...THE TIMING AND
APPROACH OF A COLD FRONT FROM THE MID-MISSISSIPPI VALLEY WILL BE
IMPACTED BY THE POSITION OF ANA AS WELL. A CONSENSUS FORECAST
PLACES INCREASING COVERAGE OF SHOWERS AND STORMS OVER THE
MOUNTAINS MONDAY JUST AHEAD OF THE FRONT...AND ACROSS THE EAST
WITH THE TROPICAL MOISTURE WITH ANA MONDAY AFTERNOON. THIS
COMBINATION LIKELY TO BRING PERIODS OF MVFR ON MONDAY WITH OVERALL
VFR OUTSIDE OF ISOLATED SHOWERS FOR SAT NIGHT AND SUNDAY. EXODUS
OF BOTH SYSTEMS LATE MONDAY NIGHT MAY BRING ENOUGH DRYING FOR A
RETURN TO OVERALL VFR DURING TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...RAB
AVIATION...JH/NF/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
116 AM EDT FRI MAY 8 2015
.SYNOPSIS...
UPPER LEVEL HIGH PRESSURE WILL REMAIN IN PLACE THROUGH THE END OF
THE WEEK...SUPPORTING EARLY JUNE LIKE TEMPERATURES. A SLOW MOVING
AREA OF LOW PRESSURE OFFSHORE WILL SLOWLY DRIFT TOWARD THE COAST
OF THE CAROLINAS THIS WEEKEND. A COLD FRONT WILL MOVE EAST ACROSS
THE AREA LATER MONDAY INTO TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1020 PM EDT THURSDAY...
RADAR IS CLEAR OF SHOWERS AND EXPECT THIS THE REST OF THE NIGHT.
FOG STILL LOOKS PATCHY AT TIMES LATE IN THE RIVER VALLEYS
THROUGHOUT THE CWA. GOING TO SEE A MIXTURE OF STARS AND
CLOUDS...WITH MORE CIRRUS AND SOME MID CLOUDS IN THE WESTERN
CWA...WITH LESS INTO THE PIEDMONT. KEPT FORECAST LOWS CLOSE TO THE
AFTERNOON FORECAST...THOUGH A COUPLE DEGREES COOLER GIVEN LACK OF
EXTENSIVE CLOUD COVER AND LIGHT/CALM WIND. STILL FOR EARLY MAY ITS
ABOUT 10 DEGREES MILDER THAN WHAT WE NORMALLY SHOULD HAVE.
PREVIOUS VALID DISCUSSION FROM EARLIER THIS AFTERNOON...
EXPECT LITTLE CHANGE IN THE WEATHER PATTERN FOR FRIDAY...ALTHOUGH
THE LOW PRESSURE SYSTEM OFF THE CAROLINA COAST WILL DRIFT A LITTLE
CLOSER TO LAND. INSTABILITY IS EXPECTED TO BE WEAKER ACROSS THE
MOUNTAINS DURING THE AFTERNOON...AND WILL KEEP SHOWER ACTIVITY
EVEN MORE SPOTTY THAN TODAY...WITH LITTLE TO NO THUNDERSTORM
ACTIVITY EXPECTED. HOWEVER...WITH THE LOW CLOSER TO OUR AREA...MAY
SEE ENOUGH MOISTURE RADIATE INLAND TO SUPPORT A FEW SHOWERS ACROSS
THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT DURING THE
AFTERNOON. HIGH TEMPERATURES WILL AGAIN RANGE FROM THE UPPER 70S
MOST LOCATIONS ACROSS THE MOUNTAINS...TO THE LOW 80S FURTHER EAST.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 345 PM EDT THURSDAY...
FOR MOST OF THIS PERIOD...THE CWA WILL BE LOCATED BETWEEN A SLOWLY
APPROACHING FRONTAL SYSTEM/UPPER TROUGH TO THE WEST AND THE
TROPICAL/SUBTROPICAL SYSTEM TO OUR EAST ACROSS EASTERN NC THROUGH
MUCH OF THIS PERIOD. THUS...MUCH OF THE CWA WILL BE IN A SUBSIDENCE
ZONE WITH LIMITED INSTABILITY. MODELS IN GENERAL AGREEMENT ON TAKING
TRACK OF TROPICAL/SUBTROPICAL SYSTEM NNW TO NEAR RDU MONDAY
AFTERNOON. PRECIPITATION WILL BE CONFINED TO TWO AREAS...DIURNALLY
DRIVEN SHOWERS AND ISOLATED THUNDERSTORMS WESTERN MOUNTAINS WHERE
INSOLATION WILL BE GREATER ALLOWING FOR BETTER DIFFERENTIAL HEATING
IN THE MOUNTAINOUS TERRAIN...SOME DYNAMIC FORCING WILL BE
APPROACHING FROM THE WEST... AND ALSO POTENTIALLY INFLUENCED BY ANY
FAR OUTER BANDS SPIRALING AROUND THE TROPICAL SYSTEM. THIS WOULD BE
THE ONLY AREA I WOULD EXPECT TO SEE ANY THUNDER AT THIS POINT. THE
FAR EASTERN AREAS...GENERALLY EAST OF LYH-DAN...COULD SEE LIGHT RAIN
SHOWERS SPIRALING AROUND THE OUTER PERIPHERY OF THE TROPICAL SYSTEM.
THERE IS NO SOLID EVIDENCE AT THIS POINT THAT ANY CORE TROPICAL
RAINFALL WOULD SPREAD INTO OUR CWA AT ANY POINT. ANY ACTIVITY IN THE
EAST WILL BE WITHIN A STABLE MARINE LAYER AND LIKELY HAVE LITTLE TO
NO THUNDER AS EVIDENCED BY THE NEAR ZERO INSTABILITY ACROSS THIS
SECTION ON ALL MODEL PROGS. IN BETWEEN...ACROSS THE BLUE RIDGE AND
INTO THE SHENANDOAH VALLEY...EXPECT LITTLE PRECIPITATION...BUT
CANNOT ENTIRELY RULE OUT AN ISOLATED SHOWER INDUCED BY OUTER
SPIRALING BANDS OF THE TROPICAL SYSTEM.
TEMPERATURES THROUGH THE PERIOD WILL AVERAGE NEAR NORMAL EAST TO
ABOVE NORMAL WEST. INCREASING EASTERLY FLOW AND CLOUD COVER EAST MAY
ALLOW A TREND TOWARD SLIGHTLY BELOW NORMAL MAX TEMPS BY THE END OF
THE PERIOD...BUT MIN TEMPS WILL REMAIN IN THE 60S THROUGHOUT THIS
REGION DURING THIS PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 350 PM EDT THURSDAY...
FINALLY...DURING THIS TIME FRAME...THERE APPEARS TO BE SOME BONAFIDE
MOVEMENT AND BREAK DOWN OF THE UPPER RIDGE SANDWICHED BETWEEN THE
SLOWLY EASTWARD PROGRESSING WESTERN/CENTRAL U.S. TROUGH AND THE
TROPICAL/SUBTROPICAL SYSTEM OFF THE EAST COAST. THE TROPICAL SYSTEM
SHOULD BEGIN AN ACCELERATED NORTHEASTWARD MOVEMENT OFF THE VA COAST
AS THE UPPER TROUGH PROGRESSES INTO THE OHIO VALLEY.
HOWEVER...INDICATIONS ARE THAT THE UPPER TROUGH WILL BEGIN TO SHEAR
OUT...WITH THE MAIN DYNAMICS MOVING MORE INTO OH AND THE NORTHEAST
U.S. MONDAY STILL APPEARS TO BE THE BEST DAY FOR WIDESPREAD
CONVECTION ACROSS THE CWA...ESPECIALLY IN THE WEST. THERE WILL
LIKELY BE SOME LINGERING SUBSIDENCE ACROSS EASTERN AREAS ON THE BACK
SIDE OF THE TROPICAL/SUBTROPICAL SYSTEM...WHICH MAKES IT
QUESTIONABLE AS TO HOW MUCH CONVECTION WILL SPREAD EAST OF THE BLUE
RIDGE AND TO WHAT LEVEL OF INTENSITY. ALL MODELS INDICATE THAT THE
BEST THREAT FOR CONVECTION...AND ANY THREAT OF STRONG TO
SEVERE...SHOULD BE MOSTLY WEST OF THE BLUE RIDGE MONDAY.
BY TUESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT A FRONT WILL
PUSH THROUGH AT LEAST THE NORTHWEST HALF OF THE REGION AND THE
TROPICAL SYSTEM WILL MOVE WELL OFF THE COAST. A DRIER AIR MASS
SHOULD BEGIN TO SPREAD INTO THE NORTHWEST HALF OF THE CWA...BUT
PERHAPS NOT AS QUICKLY AS THE GFS WOULD SUGGEST. WILL HOLD ONTO
CHANCE POPS FOR SHOWERS/THUNDERSTORMS ACROSS THE SOUTHEAST HALF INTO
TUE AFTERNOON...THEN DRY OUT ALL AREAS FOR WED. BY THU...A FAMILIAR
WEDGE PATTERN BEGINS TO SETUP WITH POTENTIAL OVERRUNNING AS A
DISTURBANCE RIDES AROUND THE WEST SIDE OF A BUILDING SUBTROPICAL
RIDGE ACROSS THE SOUTHEAST STATES. WILL HOLD OFF ON ANY MENTION OF
PRECIPITATION UNTIL THU.
TEMPERATURES WILL TREND FROM ABOVE NORMAL TUESDAY TO NEAR TO
SLIGHTLY BELOW NORMAL BY WED. THE BIGGEST TEMPERATURE CHANGE SHOULD
BE IN THE MORNING LOWS WITH DRIER AIR AND MORE EFFECTIVE RADIATIONAL
COOLING...ESPECIALLY ACROSS THE MOUNTAINS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1255 AM EDT FRIDAY...
EXPECT MAINLY VFR CONDITIONS OUTSIDE OF ANY LATE NIGHT OR PRE-DAWN
FOG INTO EARLY FRIDAY MORNING. EXPECT MAINLY CLEAR SKIES TO HELP
TEMPS DROP OFF CLOSER TO CURRENT DEWPOINTS ESPCLY IN THE VALLEYS
AND OUT EAST WHERE ALREADY SEEING SOME FOG DEVELOPMENT TAKE SHAPE.
THUS WILL BEEF UP COVERAGE TO INCLUDE A TEMPO OF MORE IFR FOG
AROUND KLWB AND PERHAPS KBCB/KLYH. COULD EVEN BE A BIT OF FOG
AROUND KROA RIGHT BEFORE DAYBREAK BUT MOSTLY BRIEF AND HIGH END
MVFR AT WORSE.
FOR FRIDAY...EXPECT SCT/BKN CIRRUS/CS THANKS TO THE LOW PRESSURE
OFF THE CAROLINA COAST. HEATING WILL AGAIN LEAD TO MORE CU
DEVELOPMENT ESPCLY MOUNTAINS WHERE A PERIOD OF VFR CIGS
POSSIBLE...MAINLY WEST OF KBCB. HOWEVER LESS INSTABILITY FOR
FRIDAY AFTERNOON...AND THEREFORE EXPECT CONVECTION TO BE MORE
WIDELY SCATTERED...MAINLY ALONG THE MOUNTAINS WEST OF THE NEW
RIVER VALLEY INTO THE MOUNTAIN EMPIRE AND NC MTNS. SINCE LATEST
GUIDANCE AGAIN PEGS THE KLWB VICINITY FOR BEST SHRA/TSRA
CHANCES...ADDED IN A VCTS MENTION THERE PER LATEST HRRR OUTPUT.
OTHERWISE WILL LEAVE OUT ANY CONVECTION MENTION AND KEEP THINGS
VFR FRIDAY AFTERNOON UNDER EASTERLY FLOW.
ISOLATED AFTERNOON AND EARLY EVENING SHOWERS AND STORMS WILL
AGAIN BE POSSIBLE MAINLY FROM KLWB TO KBLF...AND PERHAPS AROUND
KDAN BY SATURDAY. OTHERWISE TREND FOR THE AXIS OF BEST COVERAGE
WILL SLOWLY WORK ITS WAY WEST OF THE REGION. THUS EXPECTING MAINLY
VFR EXCEPT FOR SOME LATE NIGHT AND EARLY MORNING PATCHY LIGHT FOG
AS WELL AS PATCHY MVFR CLOUDS FRIDAY NIGHT INTO SATURDAY.
FORECAST CONFIDENCE SATURDAY NIGHT INTO TUESDAY REMAINS LOW.
MODEL GUIDANCE IS STILL SHOWING A DECENT AMOUNT OF VARIABILITY IN
THEIR SOLUTIONS REGARDING THE ROUTE OF NEWLY FORMED SUBTROPICAL
STORM ANA. HOWEVER THE LATEST FORECAST FROM NHC HAS THE SYSTEM
TRACKING INLAND OVER EASTERN NORTH CAROLINA MONDAY AND WELL TO THE
EAST OF THE REGION BY EARLY TUESDAY. ACCORDINGLY...THE TIMING AND
APPROACH OF A COLD FRONT FROM THE MID-MISSISSIPPI VALLEY WILL BE
IMPACTED BY THE POSITION OF ANA AS WELL. A CONSENSUS FORECAST
PLACES INCREASING COVERAGE OF SHOWERS AND STORMS OVER THE
MOUNTAINS MONDAY JUST AHEAD OF THE FRONT...AND ACROSS THE EAST
WITH THE TROPICAL MOISTURE WITH ANA MONDAY AFTERNOON. THIS
COMBINATION LIKELY TO BRING PERIODS OF MVFR ON MONDAY WITH OVERALL
VFR OUTSIDE OF ISOLATED SHOWERS FOR SAT NIGHT AND SUNDAY. EXODUS
OF BOTH SYSTEMS LATE MONDAY NIGHT MAY BRING ENOUGH DRYING FOR A
RETURN TO OVERALL VFR DURING TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...NF/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...JH/NF/WP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1150 AM MDT FRI MAY 8 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 358 AM MDT FRI MAY 8 2015
IN THE VERY NEAR TERM...FOR THIS MORNING WE HAVE ISSUED A DENSE
FOG ADVISORY FOR THE CHEYENNE TO LARAMIE STRETCH ALONG THE
INTERSTATE 80 CORRIDOR FOR AREAS OF DENSE FOG FORMING IN THE
SOUTHEASTERLY UPSLOPE FLOW THAT WILL LINGER INTO THE MID MORNING
HOURS. LESS DENSE PATCHY FOG DEVELOPING BACK TOWARDS THE CHEYENNE
AREA HERE SHORTLY BEFORE DAYBREAK...AND WE WILL CLOSELY MONITOR
TRAFFIC CAMS AND OBSERVATIONS FOR POTENTIAL OF EXPANDING THAT
ADVISORY FARTHER EAST THROUGH CHEYENNE.
OTHERWISE...WE ARE GETTING A BREAK IN THE PRECIPITATION EARLY THIS
MORNING...AND THIS TREND IS EXPECTED TO CONTINUE THROUGH MUCH OF
THE EARLY TO MID MORNING. HRRR (WHICH DID FAIRLY WELL YESTERDAY
WITH PRECIP AND CONVECTIVE DEVELOPMENT OVER THE MOUNTAINS AND
ACROSS OUR WESTERN/CENTRAL AREAS) IS AGAIN SHOWING DEVELOPMENT
ACROSS THE SOUTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES IN THE
MID TO LATE MORNING HOURS...AND MOVING THAT SHOWER ACTIVITY TO THE
EAST AND NORTHEAST THROUGH THE COURSE OF THE DAY. THIS IS THE
GENERAL BASIS OF OUR POP FORECAST TODAY...SPREADING SHOWERS
NORTHEAST ACROSS OUR AREA THROUGH TODAY WITH A FEW ISOLATED
THUNDERSTORMS POSSIBLE FOR THE SOUTHERN AND WESTERN AREAS WHERE
SLIGHTLY GREATER INSTABILITY RESIDES TODAY. WITH STRONGER
CONVECTIVE BUILDUPS IN THE WEST TODAY...EXPECT A SWITCHOVER TO
SNOW SHOWERS ABOVE 8000 FT AGAIN TODAY SO WILL HAVE TO WATCH THOSE
AREAS WHERE TRAVEL MAY BECOME A LITTLE TRICKER THIS AFTERNOON
GOING INTO THE EVENING. /JG
ATTENTION THEN SHIFTS TO A WIDESPREAD AND POTENTIALLY SIGNIFICANT
WINTER STORM POISED TO IMPACT MUCH OF THE CWA THIS WEEKEND. LATEST
WATER VAPOR SATELLITE IMAGERY SHOWS A VIGOROUS UPPER LOW SPINNING
OVER SOUTHERN CAL THIS AM. THIS SYSTEM WILL TRANSLATE EAST INTO
THE FOUR CORNERS REGION TODAY...HELPING TO REINFORCE MOIST EAST-
TO-SOUTHEAST LOW LEVEL FLOW OVER THE PLAINS. MODELS HAVE TRENDED
WARMER OVER THE LAST 24 HOURS...LIKELY DUE TO STRONG WARM/MOIST
ADVECTION OCCURRING IN THE LOW LEVELS. IT APPEARS THIS SYSTEM
WILL TRACK A LITTLE FURTHER NORTH THAN EARLIER ANTICIPATED AS
WELL...WHICH SHOULD HELP PREVENT ANY SUBSTANTIAL COLD AIR DAMMING
ALONG THE FRONT RANGE AND LIMIT THE RISK FOR AN EARLY CHANGEOVER
TO SNOW DOWN LOW. BUT...WE ARE DEFINITELY CONCERNED ABOUT THE
MOUNTAINS/ELEVATIONS ABOVE 8000 FEET LATE TONIGHT AND EARLY SAT.
SOUNDINGS OVER THE I80 SUMMIT ARE SHOWING LITTLE CHANGE IN SURFACE
TEMPS TODAY...AND WERE ALREADY A GOOD 5 DEGREES TOO WARM AT VDW AT
06Z. THAT SAID...EXPECT IT TO BE COLD ENOUGH FOR SNOW TONIGHT.
COULD HAVE SOME SIGNIFICANT IMPACTS ALONG INTERSTATE 80
OVERNIGHT...SO WILL KEEP THE START TIME AT 06Z SAT FOR THE HIGH
COUNTRY. CONFIDENCE IS NOT QUITE HIGH ENOUGH TO GO WITH A WARNING
JUST YET...AS OBS SHOW A RATHER WARM AND MOIST AIR MASS TO OUR
SOUTHEAST WHICH MAY INHIBIT ACCUMULATING SNOW. WE ARE ALSO
CONCERNED ABOUT A DRY SLOT WHICH MAY WORK INTO THE AREA ON SAT
MORNING GIVEN FAIRLY LOW 700-300 MB RH PROGS AHEAD OF THE SYSTEM.
THIS DRY POCKET WAS OBSERVED ON MORNING WATER VAPOR.
UNFORTUNATELY...THE NORTHERN TRACK OF THE STORM IS NOT EXPECTED TO
HAVE A SIGNIFICANT IMPACT ON TOTAL ACCUMULATIONS. THERE SHOULD BE
PLENTY OF COLD AIR TO WORK WITH AS H7 TEMPS ARE ALREADY AROUND -10
DEG C OVER NORTH CENTRAL MT. EXPECT RAPID SURFACE CYCLOGENESIS TO
ENSUE OVER EASTERN CO ON SAT...FORCING WINDS TO SHIFT TO A NORTH
OR NORTHEAST DIRECTION BY SAT NIGHT. GFS/NAM/ECM ARE IN EXCELLENT
AGREEMENT WITH GOOD COLD ADVECTION IN THE EVE AND OVERNIGHT. THIS
WILL FORCE SNOW LEVELS TO DECLINE QUITE RAPIDLY. IN FACT...THE
LATEST SREF RUN SHOWS WBZ HEIGHTS BELOW GROUND ACROSS THE ENTIRE
CWA (EXCEPT EXTREME SOUTHEAST NEAR KSNY) BY 06Z SUN. DURING THIS
TIME...VERTICAL ASCENT WILL INCREASE CONSIDERABLY TO THE WEST OF A
PRONOUNCED INVERTED TROUGH AXIS OVER CENTRAL NEB. GOOD INSTABILITY
WITHIN THE TROWAL REGION AND IMPRESSIVE MID LEVEL FRONTOGENESIS
WILL SUPPORT MESOSCALE BANDING. NEGATIVE SHOWALTER INDICES HANG
AROUND BETWEEN 00Z AND 06Z SUN AS WELL...SO BONAFIDE CONVECTIVE
SNOW IS QUITE POSSIBLE FOR A BRIEF PERIOD BEFORE THERMAL PROFILES
REALLY COOL DOWN. FORECAST SOUNDINGS FROM ALL MODELS SHOW DEEP
SATURATION AS WELL...SO ALL SIGNS POINT TO SOME IMPRESSIVE PCPN
TOTALS. GFS AND ECM STILL SHOW WIDESPREAD 2-3 INCH QPF VALUES OVER
THE SNOWIES AND ALL AREAS ALONG/EAST OF THE LARAMIE RANGE THROUGH
06Z MON. THE NAM HAS SIMILAR VALUES...BUT FOCUSES THEM FARTHER
EAST INTO THE NEB PANHANDLE. THIS IS STILL THE OUTLIER.
PER COORDINATION WITH WPC AND NEIGHBORING WFOS...WE INCREASED SNOW
AMOUNTS ACROSS MUCH OF THE AREA. WITH EXCELLENT UPSLOPE AND AMPLE
MOISTURE...EXPECT SOME BIG SNOW TOTALS IN THE MOUNTAINS. UPWARDS
OF TWO FEET IS NOW EXPECTED IN THE SNOWIES...BUT THERE IS QUITE A
BIT OF UNCERTAINTY FOR THE SIERRA MADRES AS THEY COULD BE SHADOWED
BY THE SNOWY RANGE. QPF HAS BEEN CONSIDERABLY LOWER THERE. ENOUGH
SUPPORTING DATA TO GO AHEAD AND ISSUE A WINTER STORM WATCH FOR
MOST AREAS OUTSIDE OF THE MOUNTAINS...STARTING SAT MID AFTN. WPC
GUIDANCE SHOWS POTENTIAL FOR WIDESPREAD 10+ INCHES AT ELEVATIONS
ABOVE 4500 FEET...SO THIS SHOULD MATCH UP VERY WELL WITH NATIONAL
CENTERS. A WARMER AND GENERALLY DRIER AIR MASS WILL LINGER ALONG
THE I80 CORRIDOR IN NEBRASKA...SO DID NOT ISSUE ANY HEADLINES FOR
THE TIME BEING. WILL LET LATER SHIFTS RE-EVALUATE. SNOW SHOULD
START TO PULL OUT BY LATE SUN AFTN OR EARLY EVE. WENT WELL BELOW
GUIDANCE FOR TEMPERATURES ON SUNDAY WITH LINGERING PCPN AND THE
ANTICIPATION OF DEEP SNOWPACK. /CLH
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 358 AM MDT FRI MAY 8 2015
BY SUNDAY NIGHT THE MODELS ARE IN GOOD AGREEMENT LIFTING THE
OPENING UPPER LOW OUT TO THE EAST OF OUR AREA WITH DRIER/COLDER
AIR WORKING IN ACROSS THE AREA THROUGH MONDAY MORNING. WE HAVE A
FEW LINGERING SNOW SHOWERS (LIGHT ADDITIONAL ACCUMULATIONS)
PROJECTED THROUGH MONDAY MORNING...THEN WE SEE A GRADUAL WARMUP
WITH WEAK UPPER RIDGING WORKING WEST TO EAST ACROSS WYOMING AND
WESTERN NEBRASKA THROUGH MIDWEEK. WE BRING IN SMALL CHANCES FOR
DIURNAL SHOWERS/ISOLATED THUNDERSTORMS MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1139 AM MDT FRI MAY 8 2015
UPSLOPE EAST-SOUTHEAST LOW LEVEL FLOW WILL RESULT IN LOW LIFR/IFR
CIGS/VSBYS ALONG AND EAST OF SOUTH LARAMIE RANGE THIS AFTERNOON
AND TONIGHT...MAINLY IMPACTING CHEYENNE. RAIN SHOWERS AND EVEN A
FEW TSTORMS WILL CONTINUE TO SPREAD NORTH ACROSS SOUTHEAST WY FROM
NORTHERN CO THIS AFTERNOON. KEPT VCTS WORDING AT LARAMIE AND
RAWLINS WHERE BREAKS IN OVC MAY RESULT IN BETTER INSTABILITY.
GENERALLY VFR CIGS ELSEWHERE...WITH BRIEF MVFR CONDITIONS WITH
PASSING SHOWERS. IT WILL BREEZY AT TIMES WITH GUSTY EAST TO
SOUTHEAST WINDS THROUGH MUCH OF THE FORECAST PERIOD WITH
INCREASING PRESSURE GRADIENT AHEAD OF APPROACHING LOW PRESSURE
SYSTEM FROM SOUTHWEST. CONDITIONS WILL DETERIORATE TO LIFR/IFR
LATER THIS EVENING THROUGH OVERNIGHT TONIGHT WITH OCCASIONAL LIGHT
RAIN AND HIGHER ELEVATION SNOW. THE MOUNTAINS WILL BE OBSCURED.
&&
.FIRE WEATHER...
ISSUED AT 358 AM MDT FRI MAY 8 2015
A STRONG WINTER STORM SYSTEM IS FORECAST TO MOVE ACROSS THE
REGION THIS WEEKEND BRINGING PERIODS OF HEAVY SNOW TO PORTIONS OF
SOUTHEASTERN WYOMING AND THE WESTERN NEBRASKA PANHANDLE. SNOW WILL
START IN THE MOUNTAINS LATER TODAY ABOVE 8000 FEET AND WILL
DEVELOP TO THE LOWER ELEVATIONS EAST OF THE FRONT RANGE INTO THE
WESTERN NEBRASKA PANHANDLE LATE SATURDAY THROUGH SUNDAY. WARMER
AND DRIER WEATHER IS NOT EXPECTED UNTIL TUESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
AFTERNOON FOR WYZ101-102-104>108-110-115-117>119.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON
FOR WYZ103-112-114-116.
NE...WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
AFTERNOON FOR NEZ002-003-019-020-095-096.
&&
$$
SHORT TERM...JG/CLH
LONG TERM...JG
AVIATION...MJ
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
534 AM MDT FRI MAY 8 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 358 AM MDT FRI MAY 8 2015
IN THE VERY NEAR TERM...FOR THIS MORNING WE HAVE ISSUED A DENSE
FOG ADVISORY FOR THE CHEYENNE TO LARAMIE STRETCH ALONG THE
INTERSTATE 80 CORRIDOR FOR AREAS OF DENSE FOG FORMING IN THE
SOUTHEASTERLY UPSLOPE FLOW THAT WILL LINGER INTO THE MID MORNING
HOURS. LESS DENSE PATCHY FOG DEVELOPING BACK TOWARDS THE CHEYENNE
AREA HERE SHORTLY BEFORE DAYBREAK...AND WE WILL CLOSELY MONITOR
TRAFFIC CAMS AND OBSERVATIONS FOR POTENTIAL OF EXPANDING THAT
ADVISORY FARTHER EAST THROUGH CHEYENNE.
OTHERWISE...WE ARE GETTING A BREAK IN THE PRECIPITATION EARLY THIS
MORNING...AND THIS TREND IS EXPECTED TO CONTINUE THROUGH MUCH OF
THE EARLY TO MID MORNING. HRRR (WHICH DID FAIRLY WELL YESTERDAY
WITH PRECIP AND CONVECTIVE DEVELOPMENT OVER THE MOUNTAINS AND
ACROSS OUR WESTERN/CENTRAL AREAS) IS AGAIN SHOWING DEVELOPMENT
ACROSS THE SOUTHERN LARAMIE...SNOWY AND SIERRA MADRE RANGES IN THE
MID TO LATE MORNING HOURS...AND MOVING THAT SHOWER ACTIVITY TO THE
EAST AND NORTHEAST THROUGH THE COURSE OF THE DAY. THIS IS THE
GENERAL BASIS OF OUR POP FORECAST TODAY...SPREADING SHOWERS
NORTHEAST ACROSS OUR AREA THROUGH TODAY WITH A FEW ISOLATED
THUNDERSTORMS POSSIBLE FOR THE SOUTHERN AND WESTERN AREAS WHERE
SLIGHTLY GREATER INSTABILITY RESIDES TODAY. WITH STRONGER
CONVECTIVE BUILDUPS IN THE WEST TODAY...EXPECT A SWITCHOVER TO
SNOW SHOWERS ABOVE 8000 FT AGAIN TODAY SO WILL HAVE TO WATCH THOSE
AREAS WHERE TRAVEL MAY BECOME A LITTLE TRICKER THIS AFTERNOON
GOING INTO THE EVENING. /JG
ATTENTION THEN SHIFTS TO A WIDESPREAD AND POTENTIALLY SIGNIFICANT
WINTER STORM POISED TO IMPACT MUCH OF THE CWA THIS WEEKEND. LATEST
WATER VAPOR SATELLITE IMAGERY SHOWS A VIGOROUS UPPER LOW SPINNING
OVER SOUTHERN CAL THIS AM. THIS SYSTEM WILL TRANSLATE EAST INTO
THE FOUR CORNERS REGION TODAY...HELPING TO REINFORCE MOIST EAST-
TO-SOUTHEAST LLVL FLOW OVER THE PLAINS. MODELS HAVE TRENDED WARMER
OVER THE LAST 24 HOURS...LIKELY DUE TO STRONG WARM/MOIST ADVECTION
OCCURRING IN THE LLVLS. IT APPEARS THIS SYSTEM WILL TRACK A LITTLE
FURTHER NORTH THAN EARLIER ANTICIPATED AS WELL...WHICH SHOULD HELP
PREVENT ANY SUBSTANTIAL COLD AIR DAMMING ALONG THE FRONT RANGE AND
LIMIT THE RISK FOR AN EARLY CHANGEOVER TO SNOW DOWN LOW. BUT...WE
ARE DEFINITELY CONCERNED ABOUT THE MOUNTAINS/ELEVATIONS ABOVE
8000 FEET LATE TONIGHT AND EARLY SAT. SOUNDINGS OVER THE I80
SUMMIT ARE SHOWING LITTLE CHANGE IN SURFACE TEMPS TODAY...AND WERE
ALREADY A GOOD 5 DEGREES TOO WARM AT VDW AT 06Z. THAT
SAID...EXPECT IT TO BE COLD ENOUGH FOR SNOW TONIGHT. COULD HAVE
SOME SIGNIFICANT IMPACTS ALONG INTERSTATE 80 OVERNIGHT...SO WILL
KEEP THE START TIME AT 06Z SAT FOR THE HIGH COUNTRY. CONFIDENCE IS
NOT QUITE HIGH ENOUGH TO GO WITH A WARNING JUST YET...AS OBS SHOW
A RATHER WARM AND MOIST AIR MASS TO OUR SOUTHEAST WHICH MAY
INHIBIT ACCUMULATING SNOW. WE ARE ALSO CONCERNED ABOUT A DRY SLOT
WHICH MAY WORK INTO THE AREA ON SAT MORNING GIVEN FAIRLY LOW
700-300 MB RH PROGS AHEAD OF THE SYSTEM. THIS DRY POCKET WAS
OBSERVED ON MORNING WATER VAPOR.
UNFORTUNATELY...THE NORTHERN TRACK OF THE STORM IS NOT EXPECTED TO
HAVE A SIGNIFICANT IMPACT ON TOTAL ACCUMULATIONS. THERE SHOULD BE
PLENTY OF COLD AIR TO WORK WITH AS H7 TEMPS ARE ALREADY AROUND -10
DEG C OVER NORTH CENTRAL MT. EXPECT RAPID SURFACE CYCLOGENESIS TO
ENSUE OVER EASTERN CO ON SAT...FORCING WINDS TO SHIFT TO A NORTH
OR NORTHEAST DIRECTION BY SAT NIGHT. GFS/NAM/ECM ARE IN EXCELLENT
AGREEMENT WITH GOOD COLD ADVECTION IN THE EVE AND OVERNIGHT. THIS
WILL FORCE SNOW LEVELS TO DECLINE QUITE RAPIDLY. IN FACT...THE
LATEST SREF RUN SHOWS WBZ HEIGHTS BELOW GROUND ACROSS THE ENTIRE
CWA (EXCEPT EXTREME SOUTHEAST NEAR KSNY) BY 06Z SUN. DURING THIS
TIME...VERTICAL ASCENT WILL INCREASE CONSIDERABLY TO THE WEST OF A
PRONOUNCED INVERTED TROUGH AXIS OVER CENTRAL NEB. GOOD INSTABILITY
WITHIN THE TROWAL REGION AND IMPRESSIVE MIDLVL FRONTOGENESIS WILL
SUPPORT MESOSCALE BANDING. NEGATIVE SHOWALTER INDICES HANG AROUND
BETWEEN 00Z AND 06Z SUN AS WELL...SO BONAFIDE CONVECTIVE SNOW IS
QUITE POSSIBLE FOR A BRIEF PERIOD BEFORE THERMAL PROFILES REALLY
COOL DOWN. FORECAST SOUNDINGS FROM ALL MODELS SHOW DEEP SATURATION
AS WELL...SO ALL SIGNS POINT TO SOME IMPRESSIVE PCPN TOTALS. GFS
AND ECM STILL SHOW WIDESPREAD 2-3 INCH QPF VALUES OVER THE SNOWIES
AND ALL AREAS ALONG/EAST OF THE LARAMIE RANGE THROUGH 06Z MON. THE
NAM HAS SIMILAR VALUES...BUT FOCUSES THEM FARTHER EAST INTO THE
NEB PANHANDLE. THIS IS STILL THE OUTLIER.
PER COORDINATION WITH WPC AND NEIGHBORING WFOS...WE INCREASED SNOW
AMOUNTS ACROSS MUCH OF THE AREA. WITH EXCELLENT UPSLOPE AND AMPLE
MOISTURE...EXPECT SOME BIG SNOW TOTALS IN THE MOUNTAINS. UPWARDS
OF TWO FEET IS NOW EXPECTED IN THE SNOWIES...BUT THERE IS QUITE A
BIT OF UNCERTAINTY FOR THE SIERRA MADRES AS THEY COULD BE SHADOWED
BY THE SNOWY RANGE. QPF HAS BEEN CONSIDERABLY LOWER THERE. ENOUGH
SUPPORTING DATA TO GO AHEAD AND ISSUE A WINTER STORM WATCH FOR
MOST AREAS OUTSIDE OF THE MOUNTAINS...STARTING SAT MID AFTN. WPC
GUIDANCE SHOWS POTENTIAL FOR WIDESPREAD 10+ INCHES AT ELEVATIONS
ABOVE 4500 FEET...SO THIS SHOULD MATCH UP VERY WELL WITH NATIONAL
CENTERS. A WARMER AND GENERALLY DRIER AIR MASS WILL LINGER ALONG
THE I80 CORRIDOR IN NEBRASKA...SO DID NOT ISSUE ANY HEADLINES FOR
THE TIME BEING. WILL LET LATER SHIFTS RE-EVALUATE. SNOW SHOULD
START TO PULL OUT BY LATE SUN AFTN OR EARLY EVE. WENT WELL BELOW
GUIDANCE FOR TEMPERATURES ON SUNDAY WITH LINGERING PCPN AND THE
ANTICIPATION OF DEEP SNOWPACK. /CLH
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 358 AM MDT FRI MAY 8 2015
BY SUNDAY NIGHT THE MODELS ARE IN GOOD AGREEMENT LIFTING THE
OPENING UPPER LOW OUT TO THE EAST OF OUR AREA WITH DRIER/COLDER
AIR WORKING IN ACROSS THE AREA THROUGH MONDAY MORNING. WE HAVE A
FEW LINGERING SNOW SHOWERS (LIGHT ADDITIONAL ACCUMULATIONS)
PROJECTED THROUGH MONDAY MORNING...THEN WE SEE A GRADUAL WARMUP
WITH WEAK UPPER RIDGING WORKING WEST TO EAST ACROSS WYOMING AND
WESTERN NEBRASKA THROUGH MIDWEEK. WE BRING IN SMALL CHANCES FOR
DIURNAL SHOWERS/ISOLATED THUNDERSTORMS MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 358 AM MDT FRI MAY 8 2015
UPSLOPE SOUTHEASTERLY FLOW FOR MUCH OF THE DAY WILL RESULT IN LOW
LIFR/IFR CEILINGS/VISIBILITIES FOR CHEYENNE FOR MUCH OF TODAY
GOING INTO THIS EVENING. DONT EXPECT AS PROLONGED OF AN IFR PERIOD
FOR LARAMIE AND SIDNEY...BUT UPSLOPE FLOW THOSE AREAS WILL RESULT
IN PERIODS OF IFR THROUGH TODAY. WILL KEEP VCTS MENTION IN FOR
LARAMIE AND RAWLINS TODAY AS BETTER INSTABILITY RESIDES ACROSS THE
WESTERN FORECAST AREA. OTHERWISE...EXPECT MVFR FLIGHT CATEGORY FOR
SCOTTSBLUFF...CHADRON AND ALLIANCE FOR MUCH OF THE MORNING INTO
THE AFTERNOON...WITH AN OVERALL DETERIORATION OF CONDITIONS AS WE
GO INTO THIS EVENING AS LOW CLOUDS AND PRECIPITATION OVERSPREAD
MANY AREAS.
&&
.FIRE WEATHER...
ISSUED AT 358 AM MDT FRI MAY 8 2015
A STRONG WINTER STORM SYSTEM IS FORECAST TO MOVE ACROSS THE
REGION THIS WEEKEND BRINGING PERIODS OF HEAVY SNOW TO PORTIONS OF
SOUTHEASTERN WYOMING AND THE WESTERN NEBRASKA PANHANDLE. SNOW WILL
START IN THE MOUNTAINS LATER TODAY ABOVE 8000 FEET AND WILL
DEVELOP TO THE LOWER ELEVATIONS EAST OF THE FRONT RANGE INTO THE
WESTERN NEBRASKA PANHANDLE LATE SATURDAY THROUGH SUNDAY. WARMER
AND DRIER WEATHER IS NOT EXPECTED UNTIL TUESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
AFTERNOON FOR WYZ101-102-104>108-110-115-117>119.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON
FOR WYZ103-112-114-116.
DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR WYZ116-117.
NE...WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
AFTERNOON FOR NEZ002-003-019-020-095-096.
&&
$$
SHORT TERM...JG/CLH
LONG TERM...JG
AVIATION...JG
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 AM EDT SUN MAY 10 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES...
WILL APPROACH THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO
EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL
BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE
WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL
REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 112 AM EDT...ISOLATED TO WIDELY SCATTERED SHOWERS REMAIN
WELL WEST OF OUR AREA AT THIS HOUR AND CONTINUING TO WEAKEN. THESE
SHOWERS ARE AHEAD OF WEAK DISTURBANCE IN ADVANCE OF A COLD FRONT.
LOCAL HI-RES WRF AND HRRR NOW INDICATING SHOWERS WILL NOT REACH
OUR AREA THROUGH THE REST OF THE NIGHT EXCEPT FOR AN ISOLATED
SHOWER OR TWO OVER THE WESTERN ADIRONDACKS.
ALSO WE HAVE ADDED PATCHY FOG TO THE MID HUDSON VALLEY...NW
CT...SE CATSKILLS AND SRN BERKSHIRES BTWN 06Z-12Z. THE LOW STRATUS
CONTINUES TO FORM AND MOVE NORTH FROM THE LOWER TO MID HUDSON
VALLEY AND SW NEW ENGLAND. EXPECT MOSTLY CLOUDY CONDITIONS FROM
THE HUDSON RIVER VALLEY EASTWARD BY DAYBREAK. LOWS TONIGHT WILL BE
VERY MILD FOR EARLY MAY IN THE MID 50S TO LOWER 60S ACROSS THE
FCST AREA. THESE MINS ARE A GOOD 10 TO 15 DEGREES ABOVE NORMAL. A
SOUTHERLY BREEZE WILL CONTINUE IN THE CAPITAL REGION WITH THE
FUNNELING EFFECT UP THE HUDSON VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
FOR SUNDAY THE COLD FRONT WILL DROP SOUTHWARD ACROSS THE NORTHERN
HALF OF THE AREA DURING THE DAY. THERE WILL BE SCATTERED SHOWERS
AND THUNDERSTORMS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT.
THERE IS A STRONG THETA E RIDGE IN PLACE ACROSS THE REGION WITH
CAPES OVER 1000 J/KG NORTH OF THE GREATER CAPITAL DISTRICT. UPPER
LEVEL Q VECTOR DIVERGENCE IS WEAK AS ARE HELICITY VALUES WHICH ARE
GENERALLY UNDER 100 M2/S2 SO NOT EXPECTING ANY SEVERE WEATHER ON
SUNDAY. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE AS PWATS
REACH ABOVE 1.50 INCHES ACROSS NORTHERN PORTIONS OF THE FA. HIGHS
SUNDAY AFTERNOON ARE EXPECTED TO RANGE FROM THE UPPER 70S
NORTHWEST TO MID 80S SOUTHEAST.
DESPITE LOSS OF DAYTIME HEATING WILL CONTINUE CHANCES FOR SHOWERS
AND THUNDERSTORMS SUNDAY NIGHT AS THE FRONTAL BOUNDARY WILL LIKELY
STALL OVER THE AREA. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO
MID 60S.
BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE
CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING
EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL
TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY
INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN
ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG
THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON
HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25
TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2. HIGHS ON
MONDAY SHOULD BE IN THE UPPER 60S TO LOWER 80S.
MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH
PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE
FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES
EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS
TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA.
SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT
THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE
IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN THE 70S TO
AROUND 80.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED FORECAST FEATURES A RETURN TO MORE SEASONABLE TEMPS FOR
MID MAY FROM THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH MAINLY
DRY WEATHER AFTER WEDNESDAY...AS A CANADIAN SFC HIGH BUILDS IN FOR
THU INTO THE WEEKEND.
TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE EAST OF THE
REGION BY TUESDAY EVENING ACCORDING TO THE MEDIUM RANGE GUIDANCE
/ECMWF...GFS...CAN GGEM/...AND MOST OF THE GEFS. HOWEVER...THE
UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING
ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW
CHC OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN
CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE MUCH COOLER BY WED
MORNING WITH H850 TEMPS FALLING TO +1C TO +4C FROM NW TO SE ACROSS
THE REGION...AND THIS IS BEFORE THE SFC TROUGH PASSAGE. THE COLD
ADVECTION WILL CONTINUE ON WED...AS IT WILL BE BRISK AND COOL. LOWS
WILL BE IN THE MID AND U40S OVER THE MTNS...AND LOWER TO MID 50S
ACROSS THE VALLEY AREAS. HIGHS WED WILL BE SLIGHTLY BELOW NORMAL
WITH U50S TO M60S IN THE VALLEY AREAS...AND U40S TO U50S OVER THE
HIGHER TERRAIN.
WED NIGHT INTO THU...THE TREND TO COOLER AND DRIER WEATHER
CONTINUES...AS THE SHOWERS WILL END BY SUNSET. IN THE COLD ADVECTION
REGIME THE GFS HAS H850 TEMPS LOWER TO -1C TO -4C OVER THE FCST
AREA. THESE H850 TEMPS ARE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL
ACCORDING TO THE LATEST 12Z GEFS. THE SKIES WILL GRADUALLY
CLEAR...AND THE WINDS WILL BE LIGHTER THAN THU. LOWS WILL BE IN THE
40-45F RANGE IN THE CAPITAL DISTRICT...MID HUDSON VALLEY...SRN
TACONICS...ERN WINDHAM CTY VT...AND NW CT...AND MAINLY 30S ELSEWHERE
OVER THE W-CNTRL MOHAWK VALLEY...ERN CATSKILLS...SRN DACKS
REGION...LAKE GEORGE REGION...THE SRN GREENS AND BERKSHIRES. THERE
SHOULD BE ENOUGH WIND TO PRECLUDE ANY FROST ISSUES THURSDAY MORNING
WHERE THE GROWING SEASON HAS BEGIN. HIGHS ON THU WITH THE SFC HIGH
BUILDING IN FROM THE GREAT LAKES REGION WILL BE INN THE LOWER TO MID
60S IN THE VALLEYS...AND 50S OVER THE HIGHER TERRAIN. THE SFC HIGH
SHOULD HAVE PLENTY OF SUBSIDENCE WITH IT FOR MOSTLY SUNNY
CONDITIONS.
THU NIGHT INTO FRIDAY...THE SFC ANTICYCLONE BUILDS IN OVER THE
NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS.
THIS WILL LIKELY BE THE COLDEST NIGHT WITH TEMPS IN THE U30S TO L40S
IN THE VALLEY AREAS...AND LOWER TO M30S OVER THE HIGHER TERRAIN.
SOME FROST ISSUES MAY ARISE IN A FEW SPOTS WHERE THE GROWING SEASON
HAS BEGIN. BY FRIDAY AFTERNOON...THE SFC HIGH MOVES OFF THE THE MID
ATLANTIC COAST...AND MID LEVEL HEIGHTS INCREASE OVER THE NORTHEAST.
ANOTHER NICE DAY IS EXPECTED WITH TEMPS NUDGING SLIGHTLY ABOVE
NORMAL WITH HIGHS IN THE U60S TO L70S IN THE VALLEY AREAS...AND
LOWER TO M60S OVER THE MTNS.
FRI NIGHT INTO SATURDAY...THE FAIR WEATHER LOOKS TO CONTINUE INTO
THE FIRST PART OF THE WEEKEND WITH THE MID-LEVEL RIDGE AXIS OVER NY
AND NEW ENGLAND. A WEAK SYSTEM TRIES TO APPROACH FROM THE TN AND OH
VALLEYS. MOST OF THE GUIDANCE KEEPS IT SOUTH AND WEST OF THE ALY
FCST AREA. A SLIGHT CHC OF SHOWERS WAS ADDED TO THE ERN
CATSKILLS/WRN MOHAWK VALLEY SAT PM...BUT OVERALL DRY WEATHER IS
EXPECTED TO START THE WEEKEND WITH TEMPS SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL BECOME STATIONARY NORTH OF THE ST LAWRENCE RIVER
VALLEY TONIGHT WITH WEAK DISTURBANCES MOVING ALONG IT. THE FRONT
WILL SLOWLY BEGIN TO SAG SOUTH TOMORROW WITH INCREASED CHANCES OF
SHOWERS AND THUNDERSTORMS ESPECIALLY NORTH OF THE MOHAWK RIVER
VALLEY.
THE FORECAST AREA WILL REMAIN IN A WARM SECTOR THROUGH THE DAY.
IT WILL BE A WARM AND HUMID AIR MASS FOR MAY...AS LOW-LEVEL
MOISTURE CONTINUES TO INCREASE IN THE BOUNDARY LAYER. THE LOW-
LEVEL SOUTHERLY FLOW WILL SUPPORT LOW STRATUS AT ALL TAF SITES
THROUGH SUNRISE. THE CEILING BETWEEN 1000-3000 FEET WILL
OCCASIONALLY BE SCATTERED BUT PREDOMINANTLY BROKEN.
THE CEILING SHOULD DEVELOP AT KALB BETWEEN 06Z-09Z. AFTER 09Z...A
LAYER BELOW 1000 FEET COULD FORM...ESPECIALLY AT KPOU AND KPSF.
PUTTING A SCATTERED LAYER BELOW 1000 FEET AT ALL TAF SITES BUT
PUTTING INTERVALS OF A BROKEN CEILING BELOW 1000 FEET AT KPOU AND
KPSF. CAN AMEND FOR KALB AND KGFL IF A CEILING BELOW 1000 FEET
DEVELOPS THERE...WHICH IS LESS LIKELY THAN AT KPOU AND KPSF.
VISIBILITIES SHOULD LOWER TO MVFR IN LIGHT MIST AS WINDS BECOME
LIGHT...LESS THAN 5 KT AT ALL SITES EXCEPT KALB WHERE STEADY 6 TO
10 KT FROM THE SOUTH IS LIKELY THROUGH SUNRISE.
AFTER ABOUT 13Z...ALL CEILINGS AND VISIBILITIES SHOULD BECOME
VFR...BUT BROKEN CEILINGS ABOVE 3000 FEET ARE LIKELY AT ALL SITES
THROUGH THE DAY...WITH PERIODS OF SCATTERED. SOME ISOLATED TO
SCATTERED SHOWERS SHOULD BUILD INTO THE REGION THIS AFTERNOON AND
EVENING...BUT AGAIN...COVERAGE SHOULD BE SCATTERED AT BEST...SO
GOING VCSH AT KGFL...KALB AND KPSF. CONFIDENCE WAS NOT GREAT
ENOUGH TO ADD THUNDER TO THE TAF SITES YET.
THE WINDS WILL BE FROM THE SOUTH AT 5-12 KTS AT KALB...KGFL AND
KPSF BUT 5 KT OR LESS AT KPOU. WINDS WILL BECOME LIGHT TO CALM AT
KPSF/KGFL/KPOU...BUT DUE TO THE CHANNELING UP THE HUDSON RIVER
VALLEY EXPECT SOUTHERLY WINDS OF 6 TO 10 KTS AT KALB THROUGH
SUNRISE. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST TOMORROW AT
8-12 KTS WITH SOME GUSTS AROUND 20 KTS AT KALB. WINDS WILL
DIMINISH TO 8 KT OR LESS THIS EVENING.
OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
HAVE ISSUED A SPS FOR BERKSHIRE AND LITCHFIELD COUNTIES FOR
ELEVATED FIRE WEATHER POTENTIAL FOR SUNDAY.
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT
LAKES...WILL APPROACH OUR REGION THROUGH SUNDAY AND MAY STALL
ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS
CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY
INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT
NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND
TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH
INCREASING HUMIDITY LEVELS.
RELATIVE HUMIDITIES WILL RISE TO 80 TO 100 PERCENT TONIGHT...FALL
TO 35 TO 55 PERCENT ON SUNDAY...RISE TO 85 TO 100 PERCENT ON
SUNDAY NIGHT AND FALL TO 45 TO 65 PERCENT ON MONDAY.
WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TONIGHT AND
SUNDAY...SOUTH 5 TO 10 MPH SUNDAY NIGHT AND SOUTH AROUND 5 MPH ON
MONDAY.
&&
.HYDROLOGY...
DRY WEATHER LOOKS TO PERSIST THROUGH MUCH OF TONIGHT...WITH
GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
SPREADING SOUTH AND EAST FROM SUNDAY THROUGH EARLY NEXT WEEK AS A
LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY
MOVE THROUGH.
IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS.
THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH
THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST
PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/JPV
NEAR TERM...JPV/WASULA
SHORT TERM...11
LONG TERM...WASULA
AVIATION...NAS
FIRE WEATHER...11
HYDROLOGY...IAA/11/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
112 AM EDT SUN MAY 10 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES...
WILL APPROACH THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO
EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL
BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE
WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL
REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 112 AM EDT...ISOLATED TO WIDELY SCATTERED SHOWERS REMAIN
WELL WEST OF OUR AREA AT THIS HOUR AND CONTINUING TO WEAKEN. THESE
SHOWERS ARE AHEAD OF WEAK DISTURBANCE IN ADVANCE OF A COLD FRONT.
LOCAL HI-RES WRF AND HRRR NOW INDICATING SHOWERS WILL NOT REACH
OUR AREA THROUGH THE REST OF THE NIGHT EXCEPT FOR AN ISOLATED
SHOWER OR TWO OVER THE WESTERN ADIRONDACKS.
ALSO WE HAVE ADDED PATCHY FOG TO THE MID HUDSON VALLEY...NW
CT...SE CATSKILLS AND SRN BERKSHIRES BTWN 06Z-12Z. THE LOW STRATUS
CONTINUES TO FORM AND MOVE NORTH FROM THE LOWER TO MID HUDSON
VALLEY AND SW NEW ENGLAND. EXPECT MOSTLY CLOUDY CONDITIONS FROM
THE HUDSON RIVER VALLEY EASTWARD BY DAYBREAK. LOWS TONIGHT WILL BE
VERY MILD FOR EARLY MAY IN THE MID 50S TO LOWER 60S ACROSS THE
FCST AREA. THESE MINS ARE A GOOD 10 TO 15 DEGREES ABOVE NORMAL. A
SOUTHERLY BREEZE WILL CONTINUE IN THE CAPITAL REGION WITH THE
FUNNELING EFFECT UP THE HUDSON VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
FOR SUNDAY THE COLD FRONT WILL DROP SOUTHWARD ACROSS THE NORTHERN
HALF OF THE AREA DURING THE DAY. THERE WILL BE SCATTERED SHOWERS
AND THUNDERSTORMS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT.
THERE IS A STRONG THETA E RIDGE IN PLACE ACROSS THE REGION WITH
CAPES OVER 1000 J/KG NORTH OF THE GREATER CAPITAL DISTRICT. UPPER
LEVEL Q VECTOR DIVERGENCE IS WEAK AS ARE HELICITY VALUES WHICH ARE
GENERALLY UNDER 100 M2/S2 SO NOT EXPECTING ANY SEVERE WEATHER ON
SUNDAY. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE AS PWATS
REACH ABOVE 1.50 INCHES ACROSS NORTHERN PORTIONS OF THE FA. HIGHS
SUNDAY AFTERNOON ARE EXPECTED TO RANGE FROM THE UPPER 70S
NORTHWEST TO MID 80S SOUTHEAST.
DESPITE LOSS OF DAYTIME HEATING WILL CONTINUE CHANCES FOR SHOWERS
AND THUNDERSTORMS SUNDAY NIGHT AS THE FRONTAL BOUNDARY WILL LIKELY
STALL OVER THE AREA. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO
MID 60S.
BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE
CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING
EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL
TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY
INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN
ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG
THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON
HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25
TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2. HIGHS ON
MONDAY SHOULD BE IN THE UPPER 60S TO LOWER 80S.
MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH
PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE
FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES
EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS
TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA.
SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT
THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE
IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN THE 70S TO
AROUND 80.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED FORECAST FEATURES A RETURN TO MORE SEASONABLE TEMPS FOR
MID MAY FROM THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH MAINLY
DRY WEATHER AFTER WEDNESDAY...AS A CANADIAN SFC HIGH BUILDS IN FOR
THU INTO THE WEEKEND.
TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE EAST OF THE
REGION BY TUESDAY EVENING ACCORDING TO THE MEDIUM RANGE GUIDANCE
/ECMWF...GFS...CAN GGEM/...AND MOST OF THE GEFS. HOWEVER...THE
UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING
ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW
CHC OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN
CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE MUCH COOLER BY WED
MORNING WITH H850 TEMPS FALLING TO +1C TO +4C FROM NW TO SE ACROSS
THE REGION...AND THIS IS BEFORE THE SFC TROUGH PASSAGE. THE COLD
ADVECTION WILL CONTINUE ON WED...AS IT WILL BE BRISK AND COOL. LOWS
WILL BE IN THE MID AND U40S OVER THE MTNS...AND LOWER TO MID 50S
ACROSS THE VALLEY AREAS. HIGHS WED WILL BE SLIGHTLY BELOW NORMAL
WITH U50S TO M60S IN THE VALLEY AREAS...AND U40S TO U50S OVER THE
HIGHER TERRAIN.
WED NIGHT INTO THU...THE TREND TO COOLER AND DRIER WEATHER
CONTINUES...AS THE SHOWERS WILL END BY SUNSET. IN THE COLD ADVECTION
REGIME THE GFS HAS H850 TEMPS LOWER TO -1C TO -4C OVER THE FCST
AREA. THESE H850 TEMPS ARE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL
ACCORDING TO THE LATEST 12Z GEFS. THE SKIES WILL GRADUALLY
CLEAR...AND THE WINDS WILL BE LIGHTER THAN THU. LOWS WILL BE IN THE
40-45F RANGE IN THE CAPITAL DISTRICT...MID HUDSON VALLEY...SRN
TACONICS...ERN WINDHAM CTY VT...AND NW CT...AND MAINLY 30S ELSEWHERE
OVER THE W-CNTRL MOHAWK VALLEY...ERN CATSKILLS...SRN DACKS
REGION...LAKE GEORGE REGION...THE SRN GREENS AND BERKSHIRES. THERE
SHOULD BE ENOUGH WIND TO PRECLUDE ANY FROST ISSUES THURSDAY MORNING
WHERE THE GROWING SEASON HAS BEGIN. HIGHS ON THU WITH THE SFC HIGH
BUILDING IN FROM THE GREAT LAKES REGION WILL BE INN THE LOWER TO MID
60S IN THE VALLEYS...AND 50S OVER THE HIGHER TERRAIN. THE SFC HIGH
SHOULD HAVE PLENTY OF SUBSIDENCE WITH IT FOR MOSTLY SUNNY
CONDITIONS.
THU NIGHT INTO FRIDAY...THE SFC ANTICYCLONE BUILDS IN OVER THE
NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS.
THIS WILL LIKELY BE THE COLDEST NIGHT WITH TEMPS IN THE U30S TO L40S
IN THE VALLEY AREAS...AND LOWER TO M30S OVER THE HIGHER TERRAIN.
SOME FROST ISSUES MAY ARISE IN A FEW SPOTS WHERE THE GROWING SEASON
HAS BEGIN. BY FRIDAY AFTERNOON...THE SFC HIGH MOVES OFF THE THE MID
ATLANTIC COAST...AND MID LEVEL HEIGHTS INCREASE OVER THE NORTHEAST.
ANOTHER NICE DAY IS EXPECTED WITH TEMPS NUDGING SLIGHTLY ABOVE
NORMAL WITH HIGHS IN THE U60S TO L70S IN THE VALLEY AREAS...AND
LOWER TO M60S OVER THE MTNS.
FRI NIGHT INTO SATURDAY...THE FAIR WEATHER LOOKS TO CONTINUE INTO
THE FIRST PART OF THE WEEKEND WITH THE MID-LEVEL RIDGE AXIS OVER NY
AND NEW ENGLAND. A WEAK SYSTEM TRIES TO APPROACH FROM THE TN AND OH
VALLEYS. MOST OF THE GUIDANCE KEEPS IT SOUTH AND WEST OF THE ALY
FCST AREA. A SLIGHT CHC OF SHOWERS WAS ADDED TO THE ERN
CATSKILLS/WRN MOHAWK VALLEY SAT PM...BUT OVERALL DRY WEATHER IS
EXPECTED TO START THE WEEKEND WITH TEMPS SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL BECOME STATIONARY NORTH OF THE ST LAWRENCE RIVER
VALLEY TONIGHT WITH WEAK DISTURBANCES MOVING ALONG IT. THE FRONT
WILL SLOWLY BEGIN TO SAG SOUTH TOMORROW WITH INCREASED CHANCES OF
SHOWERS AND THUNDERSTORMS ESPECIALLY NORTH OF THE MOHAWK RIVER
VALLEY.
THE FORECAST AREA WILL REMAIN IN A WARM SECTOR TONIGHT. IT WILL BE
A WARM AND HUMID AIR MASS FOR MAY...AS LOW-LEVEL MOISTURE
CONTINUES TO INCREASE IN THE BOUNDARY LAYER. THE LOW-LEVEL
SOUTHERLY FLOW WILL ALLOW LOW STRATUS TO FORM FOR
KPOU...KPSF...KGFL...AND KALB TONIGHT. THE LOW STRATUS IS EXPECTED
TO FORM BTWN 03Z-06Z WITH MVFR CONDITIONS WITH CIGS BTWN 1-1.5 KFT
AGL. EXPECT THE CIGS TO LOWER TO IFR LEVELS WITH SOME MIST AT KPOU
AND KPSF PRIOR TO OR AROUND 06Z. THE IFR CIGS AND VSBYS WILL LAST
UNTIL 12Z-15Z AT THESE SITES. IT IS TOUGH TO DISCERN IF KALB WILL
HAVE IFR CIGS DUE TO A STEADY SOUTHERLY BREEZE UP THE HUDSON RIVER
VALLEY...SO LOW MVFR CIGS WERE LEFT THERE. KGFL...THE WINDS ARE
EXPECTED TO BECOME LIGHT TO CALM...AND IFR CIGS/VSBYS HAVE BEEN
FORECASTED FROM 09Z-13Z.
THE STRATUS WILL ERODE BELOW THE LOW-LEVEL INVERSION IN THE LATE
MORNING WITH CIGS/VSBYS RISING BACK TO VFR LEVELS DUE TO SOME
SUNSHINE AND MIXING. HOWEVER...MID CLOUDS WILL INCREASE AND THE
THREAT FOR SOME SCT SHOWERS AND THUNDERSTORMS WELL IN ADVANCE OF
THE COLD FRONT. VCSH GROUPS WERE ADDED TO KGFL/KALB/KPSF BTWN
18Z-21Z. OUR CONFIDENCE WAS NOT GREAT ENOUGH TO ADD THUNDER TO THE
TAF SITES YET.
THE WINDS WILL BE FROM THE SOUTH AT 5-12 KTS EARLY TONIGHT...AND
THEY WILL BECOME LIGHT TO CALM AT KPSF/KGFL/KPOU...BUT DUE TO THE
CHANNELING UP THE HUDSON RIVER VALLEY EXPECT SOUTHERLY WINDS OF
AROUND 10 KTS AT KALB THROUGHOUT THE NIGHT. THE WINDS WILL BE FROM
THE SOUTH TO SOUTHWEST TOMORROW AT 8-12 KTS WITH SOME GUSTS AROUND
20 KTS AT KALB.
OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
HAVE ISSUED A SPS FOR BERKSHIRE AND LITCHFIELD COUNTIES FOR
ELEVATED FIRE WEATHER POTENTIAL FOR SUNDAY.
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT
LAKES...WILL APPROACH OUR REGION THROUGH SUNDAY AND MAY STALL
ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS
CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY
INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT
NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND
TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH
INCREASING HUMIDITY LEVELS.
RELATIVE HUMIDITIES WILL RISE TO 80 TO 100 PERCENT TONIGHT...FALL
TO 35 TO 55 PERCENT ON SUNDAY...RISE TO 85 TO 100 PERCENT ON
SUNDAY NIGHT AND FALL TO 45 TO 65 PERCENT ON MONDAY.
WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TONIGHT AND
SUNDAY...SOUTH 5 TO 10 MPH SUNDAY NIGHT AND SOUTH AROUND 5 MPH ON
MONDAY.
&&
.HYDROLOGY...
DRY WEATHER LOOKS TO PERSIST THROUGH MUCH OF TONIGHT...WITH
GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
SPREADING SOUTH AND EAST FROM SUNDAY THROUGH EARLY NEXT WEEK AS A
LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY
MOVE THROUGH.
IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS.
THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH
THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST
PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/JPV
NEAR TERM...JPV/WASULA
SHORT TERM...11
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/11/JPV
AREA FORECAST DISCUSSION
NWS LINCOLN IL
329 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF
10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE
SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR
WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE
CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN
CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING
THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER
SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC
SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI.
GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT
RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS
MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE
AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE
CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA
STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON.
BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS
SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF
MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE
AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE
SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT
EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER
GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY
DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL
DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE
CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST
ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS
DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS
THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE
SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND
HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH
TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS
WILL TOP THE 80 DEGREE MARK.
&&
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS
EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL
TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING
INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS
THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS
ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE
MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN
PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA
MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING
FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE
AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED
POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON.
ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE
60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL
BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF
ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND
INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL
SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE
SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24
HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE
CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE
GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO
THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1200 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT THROUGH ALL TAFS, SO
WILL KEEP VCSH AT ALL TAFS THROUGH MORNING HOURS. AREA OF
CONVECTION IN OK/ARK/SRN MO WILL MOVE ENE ACROSS SOUTHERN IL
OVERNIGHT AND SHOULD REMAIN SOUTH OF THE TAFS. COULD BE SOME
LINGERING SHOWERS REACH UP INTO THE AREA, BUT WILL NOT INCLUDE
ANYTHING FOR NOW. MORE PCPN IS POSSIBLE TONIGHT SO WILL HAVE VCTS
IN TAFS STARTING LATE AFTERNOON THROUGH EVENING HOURS. NOT SURE
WHEN A TEMPO GROUP FOR THUNDERSTORMS IS WARRANTED SO WILL LEAVE
OUT FOR NOW. IFR CONDITIONS HAVE MOVED INTO THE AREA AT ALL SITES
AND WILL LIKELY CONTINUE OVERNIGHT. THEN BY MORNING CIGS WILL
IMPROVE INTO THE MVFR CATEGORY. BY EVENING WHEN THE STORMS WILL BE
AROUND, VFR CONDITIONS WILL PREVAIL. WINDS WILL BE NORTHEAST AT
PIA/BMI WHICH ARE NORTH OF THE FRONT FOR NOW. SOUTH TO SOUTHEAST
WINDS WILL PREVAIL AT SPI/DEC/CMI. PIA AND BMI WILL SEE WINDS
BECOME SOUTHERLY DURING THE AFTERNOON/EVENING AS THE FRONT LIFTS
NORTH OF THE SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1200 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 901 PM CDT SAT MAY 9 2015
SCATTERED SHOWERS CONTINUE ACROSS THE AREA THIS EVENING AND WITH
REMNANTS OF ANOTHER MCS COMING IN FOR LATER TONIGHT...SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE OVERNIGHT. SKIES
WILL REMAIN MOSTLY CLOUDY SO DO NOT THINK MUCH FOG WILL OCCUR LATE
TONIGHT LIKE LAST NIGHT. CLOUDS WILL KEEP TEMPS UP AS WELL AND
CURRENT FORECAST LOW LOOKS FINE. GIVEN RADAR TRENDS HAVE MADE SOME
ADJUSTMENTS TO THE POP/WX GRIDS. SO UPDATE WILL BE COMING SHORTLY.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 251 PM CDT SAT MAY 9 2015
A QUASI-STATIONARY FRONTAL BOUNDARY FROM JUST SOUTH OF ST LOUIS AND
FLORA TO TERRE HAUTE WILL SLOWLY LIFT BACK NORTH AS A WARM FRONT
TOWARD I-72 TONIGHT (STAYING SOUTH OF I-72 TONIGHT). AREA OF SHOWERS
AND THUNDERSTORMS WITH SOME HEAVY RAIN WAS ALONG AND SOUTH OF A
TAYLORVILLE TO MATTOON TO PARIS LINE AND LIFTING SLOWLY NORTHWARD.
THIS ASSOCIATED WITH MCV EAST OF ST LOUIS AND SLOWLY TRACKING NNE
INTO SW IL AT MID AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD
NORTHWARD ACROSS CENTRAL IL LATE THIS AFTERNOON AND EVENING WHILE
BECOMING MORE SCATTERED IN SOUTHEAST IL AS THEY GET INTO THE WARM
SECTOR. TAIL END OF HRRR MODEL AND RAP13 MODEL SHOW MORE CONVECTION
SPREADING NE INTO SW CWA LATER TONIGHT AHEAD OF YET ANOTHER MCV OVER
EASTERN OK. SPC KEEPS MARGINAL RISK OF SEVERE STORMS SW OF IL OVER
MO THROUGH TONIGHT. A FEW STRONGER THUNDERSTORMS COULD HAVE WIND
GUSTS OVER 40 MPH WITH PEA SIZE HAIL AND HEAVY RAINS NEAR 1 INCH IN
LESS THAN AN HOUR. LOWS TONIGHT RANGE FROM UPPER 50S TO AROUND 60F
NORTH OF LINCOLN TO THE MID 60S FROM JACKSONVILLE AND SPRINGFIELD TO
MATTOON SOUTH.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 251 PM CDT SAT MAY 9 2015
UNSETTLED AND UNSEASONABLY MILD WEATHER PATTERN WILL PERSIST ACROSS
CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. STILL A COUPLE MORE
WAVES IN THE PERSISTENT SOUTHWESTERLY FLOW ALOFT NEED TO MOVE
THROUGH THE AREA BEFORE THE VIGOROUS CUT-OFF UPPER LOW OVER THE FOUR
CORNERS REGION FINALLY DRIVES A COLD FRONT THROUGH THE AREA. THIS
FRONT WILL BE FOLLOWED BY COOLER & DRIER AIR FOR MUCH OF THE WORK
WEEK.
SUNDAY SHOULD START OUT WITH SHOWERS/STORMS ACROSS MUCH OF THE
REGION AS A DISTURBANCE, CURRENTLY PRODUCING VIGOROUS CONVECTION
ACROSS THE SOUTHERN PLAINS, TRACKS NORTHEAST ACROSS THE AREA. DO NOT
EXPECT THE MORNING STORMS TO BE SEVERE. THEN, ATTENTION TO THE UPPER
AND ASSOCIATED SURFACE LOW THAT WILL BE PICKING UP STEAM AS IT TRACK
NORTHEAST ACROSS THE PLAINS. A WARM FRONT EXTENDING SOUTHEAST FROM
THE LOW ACROSS THE MIDWEST WILL LIFT NORTH THROUGH THE DAY. STILL
SOME SIGNIFICANT MODEL DISAGREEMENT WITH RESPECT TO HOW QUICKLY THE
FRONT LIFTS NORTHWARD. THE POSITION OF THIS FRONT DURING PEAK
HEATING WILL BE KEY TO WHERE THE BEST SEVERE WEATHER THREAT WILL
EXIST. AT THIS POINT, IT APPEARS THE BEST SHEAR/INSTABILITY WILL CO-
EXIST ACROSS THE NORTHERN PORTION OF THE FORECAST AREA INTO NORTHERN
ILLINOIS. THE SHEAR PROFILES WILL BE SUBSTANTIALLY MORE IMPRESSIVE
FURTHER NORTHWEST, ACROSS IOWA, CLOSER TO THE TRACK OF THE
UPPER/SURFACE LOW. THE LOWS WILL TRACK ACROSS THE GREAT LAKES ON
MONDAY DRAGGING THE TRAILING COLD FRONT THROUGH ILLINOIS. STILL SOME
MODEL DISAGREEMENT IN THE SPEED OF THE COLD FRONT, WHICH WILL BE KEY
TO THE SEVERE WEATHER THREAT ON MONDAY. THE NAM, WHICH HAD BEEN THE
QUICKEST MODEL, IS NOW AMONG THE SLOWEST SOLUTIONS. CONTINUE TO
FAVOR A SLOWER SOLUTION GIVEN THE CURRENT POSITION/SPEED OF THE
SYSTEM OVER THE SOUTHWEST STATES, AND A TYPICAL MODEL BIAS OF BEING
TOO QUICK MOVING CUT-OFF LOWS. THESE FACTORS CONSIDERED, IT APPEARS
THAT THE BEST THREAT FOR SEVERE WEATHER ON MONDAY LOCALLY IS ACROSS
EAST CENTRAL AND SOUTHEAST ILLINOIS DURING THE MONDAY
AFTERNOON/EARLY EVENING HOURS.
QUIETER AND COOLER WEATHER IS EXPECTED TO ARRIVE MONDAY NIGHT AND
LINGER FOR MUCH OF THE REMAINDER OF THE WEEK. DAYTIME HIGHS THAT HAD
FREQUENTLY BEEN IN THE 80S AHEAD OF THE FRONT WILL MAINLY BE IN THE
60S AFTER FRONTAL PASSAGE. THE ECMWF, WHILE SLOWER THAN IT WAS A
COUPLE DAYS AGO, IS STILL THE QUICKEST TO BRING A SYSTEM BACK INTO
THE AREA BY THE END OF THE WEEK AS SOUTHWEST UPPER-LEVEL FLOW
REDEVELOPS AND TEMPERATURES TEND TO CLIMB BACK TOWARD NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1200 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT THROUGH ALL TAFS, SO
WILL KEEP VCSH AT ALL TAFS THROUGH MORNING HOURS. AREA OF
CONVECTION IN OK/ARK/SRN MO WILL MOVE ENE ACROSS SOUTHERN IL
OVERNIGHT AND SHOULD REMAIN SOUTH OF THE TAFS. COULD BE SOME
LINGERING SHOWERS REACH UP INTO THE AREA, BUT WILL NOT INCLUDE
ANYTHING FOR NOW. MORE PCPN IS POSSIBLE TONIGHT SO WILL HAVE VCTS
IN TAFS STARTING LATE AFTERNOON THROUGH EVENING HOURS. NOT SURE
WHEN A TEMPO GROUP FOR THUNDERSTORMS IS WARRANTED SO WILL LEAVE
OUT FOR NOW. IFR CONDITIONS HAVE MOVED INTO THE AREA AT ALL SITES
AND WILL LIKELY CONTINUE OVERNIGHT. THEN BY MORNING CIGS WILL
IMPROVE INTO THE MVFR CATEGORY. BY EVENING WHEN THE STORMS WILL BE
AROUND, VFR CONDITIONS WILL PREVAIL. WINDS WILL BE NORTHEAST AT
PIA/BMI WHICH ARE NORTH OF THE FRONT FOR NOW. SOUTH TO SOUTHEAST
WINDS WILL PREVAIL AT SPI/DEC/CMI. PIA AND BMI WILL SEE WINDS
BECOME SOUTHERLY DURING THE AFTERNOON/EVENING AS THE FRONT LIFTS
NORTH OF THE SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...07
LONG TERM...BAK
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1137 PM CDT SAT MAY 9 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
QUIET FOR THE REST OF SATURDAY AND THEN STORM CHANCES ENTER THE FCST
LATE IN THIS SHORT TERM PERIOD. A POCKET OF DRIER AIR HAS BEEN IN
PLACE MOST OF SATURDAY AFTERNOON ACROSS THE CWA ALLOWING FOR
SUNSHINE TO PUNCH THROUGH ACROSS THE CENTRAL TO NORTHERN PARTS OF
OUR CWA.
THE LARGE AREA OF LOW PRESSURE WE HAVE BEEN TALKING ABOUT
FOR THE PAST FEW DAYS HAS REACHED THE FOUR CORNERS REGION OF THE
CONUS. THIS LOW IS SLATED TO BE LOCATED OVER WESTERN NEBRASKA BY 12Z
SUN. THE NAM IS A SLIGHT OUTLIER...KEEPING THIS SYSTEM SLOWER AND
FURTHER TO THE SOUTH THAN THE REST OF GUIDANCE. THE GFS IS THE
FASTEST. LEANED TOWARDS THE EURO...WHICH IS IN THE MIDDLE...FOR
TIMING. FOR LOW LEVEL MOISTURE INIT...USUAL MODEL BIASES IN PLACE.
THE NAM IS THE MOST MOIST...WHILE THE GFS IS OVERLY DRY. LEANED
TOWARDS EURO ONCE AGAIN.
AHEAD OF THIS AREA OF LOW PRESSURE...A WARM FRONT WILL BE PASSING
THROUGH OUR CWA FROM SW TO NE. ALL MODELS SHOW THE GULF IS WIDE OPEN
FOR MOISTURE TRANSPORT VIA THE LLJ...THE NOSE OF WHICH WILL BE ALONG
THE WESTERN/CENTRAL PART OF OUR CWA AT 12Z SUN. REGARDING THE SEVERE
WEATHER POTENTIAL...THE RAP SHOWS 0-1KM BULK SHEAR VALUES IN THE 20
TO 25KT RANGE...HELICITY IN THE 200 TO 400 RANGE AND LOW ENOUGH LCL
HEIGHTS TO SUGGEST TORNADOES MAY BE A SEVERE MODE THREAT EARLY ON.
DCAPE VALUES ARE ALSO HIGH EARLY ON...SO DAMAGING WINDS IS ALSO A
THREAT. LOCATION-WISE...THIS WILL MAINLY BE IN THE WESTERN/SW CWA AT
12Z. THE EVOLUTION OF SUNDAY/S SEVERE WEATHER WILL BE HANDLED IN THE
LONG TERM.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SEVERE WEATHER POTENTIAL FOR
SUNDAY INTO SUNDAY NIGHT. THE REMAINDER OF THE FORECAST TIME FRAME
REMAINS RELATIVELY QUIET UNTIL LATE IN THE WORK WEEK.
SUNDAY INTO SUNDAY NIGHT...POTENTIAL EXISTS FOR AT LEAST TWO
ROUNDS OF SEVERE WEATHER ON MOTHERS DAY...WITH THE MORNING
CONVECTION SURGING NORTHWARD WITH THE WARM FRONT THROUGH 15Z AND
THEN THE DIURNALLY DRIVEN CONVECTION IN THE AFTERNOON ALONG THE
DRY LINE BY THE LATE AFTERNOON/EARLY EVENING. LEANED TOWARD THE
NAM12/ARWWRF FOR TIMING OF POPS SUNDAY INTO SUNDAY NIGHT EVEN
THOUGH MODELS ARE IN FAIRLY GOOD AGREEMENT WRT TO SURFACE LOW
TRACK AND TIMING OF COLD FROPA SUNDAY EVENING. THIS RESULTED IN
DELAYING THE AFTERNOON CONVECTION SLIGHTLY AS INITIATION LOOKS TO
BE AFTER 20Z SUNDAY OVER WESTERN PORTIONS OF THE FORECAST AREA.
THE WARM FRONT LOOKS TO SURGE NORTHWARD TO THE IOWA/MINNESOTA
BORDER BY AROUND 00Z MONDAY WITH THE SURFACE LOW CENTERED OVER
FAR NORTHWEST CORNER OF IOWA AND FAR SOUTHEAST SOUTH DAKOTA. THE
STRONGER AND DEEPER FORCING FOR ASCENT IS IN THIS LOCATION BUT
QUESTIONABLE WHETHER SURFACE INSTABILITY RECOVERS ENOUGH TO
SUPPORT LOW-LIVED TORNADIC SUPERCELLS. HOWEVER...ENOUGH ELEVATED
MUCAPE PRESENT COMBINED WITH STRONG LOW LEVEL SHEAR AND VORTICITY
WITHIN THE VICINITY OF THE WARM FRONT LOOKS TO COUNTERACT THE LACK
OF SURFACE INSTABILITY AND CERTAINLY PROVIDE A DECENT THREAT FOR
TORNADOES AND LARGE HAIL OVER WEST-CENTRAL TO NORTH-CENTRAL IOWA
TOMORROW AFTERNOON. DEEP LAYER SHEAR FROM 50 TO NEAR 70 KNOTS
PLENTY STRONG ENOUGH TO KEEP CONVECTION THROUGH THE EVENING SUNDAY
AS THE COLD FRONT PUSHES ACROSS IOWA. SEVERE POTENTIAL EXISTS
ALONG THE COLD FRONT WITH STRAIGHT-LINE WINDS THROUGH ROUGHLY 03Z
MONDAY BEFORE ENVIRONMENT BECOMES LESS FAVORABLE. THINKING ANY
SUPERCELLS THAT DEVELOP LATE TOMORROW AFTERNOON WILL MORPH INTO A
QLCS TYPE STRUCTURE WITH THE ADVANCEMENT OF THE COLD FRONT...WHICH
WOULD KEEP THE ROUNDS OF SEVERE WEATHER AT ONLY TWO. IF CONVECTION
PUSHES NORTH INTO MINNESOTA THEN A THIRD ROUND ALONG THE COLD
FRONT SEEMS FEASIBLE TOMORROW EVENING WITHIN THE DMX CWA.
MONDAY THROUGH WEDNESDAY...STRONG CAA DEVELOPS ON MONDAY INTO
MONDAY NIGHT AND MAY SEE A FEW SHOWERS ACROSS THE NORTH WITH
SOME WRAP-AROUND MOISTURE FROM THE SURFACE LOW. OTHERWISE...COOL
AND DRY CONDITIONS THROUGH WEDNESDAY.
THURSDAY INTO SATURDAY...LARGE UPPER LEVEL RIDGE BEGINS TO BREAK
DOWN WITH A FAIRLY STRONG VORT MAX EJECTING OUT OF THE SOUTHERN
ROCKIES THURSDAY. UNCERTAINTY IN TIMING WITH THE ECMWF ROUGHLY 12
HOURS QUICKER THAN THE GFS. BY THE END OF THE WORK WEEK AND INTO
NEXT WEEKEND...THE REGION IS PLACED BACK INTO SOUTHWEST FLOW ALOFT
AND EXTENDED MODELS HAVE MULTIPLE SHORTWAVES TO AFFECT THE FORECAST
AREA.
&&
.AVIATION...10/06Z
ISSUED AT 1136 PM CDT SAT MAY 9 2015
LATEST DATA SHOWS LITTLE CHANGE FROM PREVIOUS THINKING. STORMS
WILL FORM OVER NEBRASKA/WESTERN IA AND MOVE NORTH NORTHEAST
OVERNIGHT WITH POTENTIAL FOR SOME THUNDER AFT 09-10Z FOR KFOD AND
KDSM...LESSER CHANCES NOW FOR KALO|KOTM|KMCW OTHER THAN POSSIBLE
SHRA THROUGH 18Z AS INSTABILITY WILL WEAKEN FARTHER NORTH
OVERNIGHT AND EARLY SUNDAY. BREAK IN STORMS EXPECTED WEST/SOUTH
AFT 14-15Z SUN. CONDITIONS REMAIN LOW MVFR TO PERHAPS IFR NORTH
FOR MOST OF DAY...ELSEWHERE MVFR. RAP40 SHOWS POTENTIAL FOR SOME
TSRA REDEVELOPMENT AS EARLY AS 18Z SOUTHWEST/WEST WITH MAIN LINE
MOVING ACROSS AREA FROM 20|21Z THROUGH 06Z EAST AS DRY LINE IS
FORCED THROUGH THE AREA. BEST CHANCE FOR STRONG TO SVR STORMS WILL
BE WITH AFTERNOON PASSAGE OF DRY LINE. SOME LINGERING -SHRA AND SW
WINDS EXPECTED AFT 00Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KOTENBERG
LONG TERM...PODRAZIK
AVIATION...REV
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1154 PM CDT Sat May 9 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Sunday)
Issued at 322 PM CDT SAT MAY 9 2015
An intense upper level trough was located across northwest NM. An 80
KT H5 jet max was lifting northeast across west TX into southwest
KS. A dryline was sharpening up from southeast CO, south-southeast
across the eastern TX PNHDL, then south into the hill country of
west central TX. The center of a lee cyclone, north of TAD. The warm
front extended east south-southeast from the lee cyclone, across
southwest KS, then east along the KS and OK border. A band of
elevated thunderstorms that formed across southeast CO and the TX
PNHDL earlier this morning continues to slowly move northeast across
central and south central KS. The area of elevated thunderstorms
were beginning to weaken as they move northeast into a more stable
airmass across eastern KS. An MCS was forming across central OK and
will move east-northeast across northeast OK into southwest MO.
The CWA will see a gradual increase in isolated to scattered shower
and thunderstorms late this afternoon, but with MUCAPES only 500 to
1000 J/KG these storms will not become severe this afternoon. As the
warm front begins to push north, the isentropic lift will begin to
weaken and we may see a break in the shower and thunderstorms
activity through the mid evening hours. Farther west, the atmosphere
is beginning to recover from the morning convection across the
eastern TX PNHDL, eastern CO and western KS. As the upper low over
northwest NM lifts northeast into east-central CO, numerous
thunderstorms should develop along the dryline as it begins to push
northeast across the eastern TX PNHDL into southwest KS and east
central CO. Intense upper level ascent ahead of the lifting upper
low will allow scattered supercell thunderstorms across western KS
to congeal into a QLCS or an MCS through the evening hours across
western KS. This storm complex will lift northeast across north
central KS late this evening and through the early morning hours of
Sunday. If a complex of thunderstorms develop the primary hazards
will be large hail, damaging winds and heavy rain. The meso-scale
models such as the RAP and WRF move the more intense portions of the
MCS north-northeast into southern NE just west of the CWA. Though,
there may be enough ascent that scattered thunderstorms will develop
south-southeast of this complex of thunderstorms. The primary hazard
of any severe thunderstorms across the CWA later Tonight will be
large hail, damaging wind gusts and heavy rainfall. The vertical
wind shear and MUCAPE do increase later Tonight, thus if a supercell
thunderstorm develops the boundary layer may not be decoupled enough
to prevent isolated tornadoes. However, at this time the better
chances for tornadic supercells will be this evening across western
KS.
Due to the uncertainty in the intensity and areal extent of wide
spread deep moist convection, I will not be issuing a flash flood
watch for the CWA. There is a chance for locally heavy rainfall with
any convective complex that develops. The isolated to scattered
thunderstorms later Tonight will move quickly to the northeast, so
expect only brief heavy rainfall. The better chances for heavy
rainfall will be associated with MCS`s that are forecasted to move
southeast and northwest of the CWA.
Sunday, there may be a few morning storms across the eastern
counties of the CWA. The upper low will begin to slowly fill as it
lifts northeast-northeast into western NE during the day. A strong
H5 jet max of 50 to 60 KTS will over spread eastern KS through the
afternoon hours. A cold front will quickly occlude the dryline
across central KS during the mid and late morning hours and the cold
front will push east across the western half of the CWA during the
early Afternoon hours. The numerical models all show the 850mb winds
slowly veering to the southwest ahead of the surface front. However,
the numerical models forecast southerly or even southeasterly
surface wind ahead of the surface front. The deepest gulf moisture
may get shunted eastward across MO into eastern IA but several
mesoscale models are showing 10 to 12 DEG Td at 850mb remaining
ahead of the surface front. There should be enough deep moisture and
instability for scattered thunderstorms to begin to develop along
the surface cold front by 20Z. The front should extend roughly from
a Seneca to Manhattan to Council Grove line by 3 PM. Thunderstorms
that develop will rapidly become severe given MLCAPES of 1500 to
2500 J/KG and SFC to 6KM effective shear of 50 to 60 KTS. Even
though 850mb winds begin to veer slightly the surface winds may
remain back. Therefore as storms first form they may be isolated to
scattered supercells before congealing into a squall line which will
then push east across northeast and east central KS during the late
afternoon hours. The 0-1 SRH of 150 to 250 J/KG may support any
discrete supercell to produce isolated tornadoes. Once the isolated
to scattered supercells merge into a squall line then the primary
hazards will be damaging winds gusts, large hail and heavy rainfall.
The line will move fairly fast across the eastern counties of the
CWA and begin to weaken after 6 PM due to the loss of surface
heating. Highs just behind the surface front across the central
counties of the CWA may reach to around 80 degrees, with most other
areas getting into the mid to upper 70s.
.LONG TERM...(Sunday Night through Saturday)
Issued at 322 PM CDT SAT MAY 9 2015
Sunday Night through Monday Night ...
By Sunday evening, models are in fairly good agreement with the
surface and mid-level patterns. A closed mid-level low should be
centered over the northern High Plains with the deep trough
stretching all the way southward toward the U.S./Mexico border. At
the surface, the center of low pressure should be focused across
northeast Nebraska with the associated cold front extending
southward and essentially bisecting the forecast area (i.e.,
stretching from Marysville to Manhattan to Herington by early
evening). This front placement is a bit further west than what
models were suggesting yesterday. Model soundings show little to no
inhibition in place across the area by late afternoon/early evening.
Expect decent advection of warm, moist air ahead of this boundary
from the breezy southerly winds, resulting in a decent set-up for
some strong to severe thunderstorms late afternoon into the evening
hours. Models suggest that isolated storms should develop along and
ahead of the cold front by late afternoon/early evening and quickly
congeal into a line of storms as the wind profiles look to prevail
out of the southwest. With a north/south oriented boundary, this
southwesterly flow should help to advance this line of storms fairly
quickly eastward across eastern KS with most of the forecast area
dry by midnight. Increasing low-level cloud cover combined with
little inhibition may result in slightly lower CAPE values upwards
of 1500-1800J/kg. Wind profiles show fairly unidirectional winds out
of the southwest with a 60-70kt 500mb jet, however there are some
discrepancies with regards to how much winds will veer in the lowest
2km of the atmosphere. As a result, there is a notable range amongst
the models in 0-1km helicity values across far eastern Kansas. LCL
values should be fairly low at around 3000ft or less, but the lapse
rates do not look that great. With these conditions and model
discrepancies in mind, confidence is low in the tornado threat
across eastern Kansas Sunday evening however an isolated tornado or
two still cannot be ruled out. Expect upwards of 50-60kts of 0-6km
shear, so combined with the modest instability the primary severe
threats look to be large hail and strong winds. Some locally heavy
rainfall will also be possible, which may potentially result in some
localized flash flooding and/or river flooding as some locations
have already received a few inches of rain this week. However, with
1-hr and 3-hr flash flood guidance near 2 inches, do not expect
widespread flooding concerns with these fast-moving storms.
Winds will slowly veer toward the west overnight into Monday morning
with clearing skies. As a result, decent radiational cooling should
help to drop low temperatures into the 40s. The mid-level trough
will lift northward out of the area through the day on Monday with
surface high pressure advancing into the High Plains behind this
exiting system. West-northwesterly surface winds will usher cooler
air into the region, keeping Monday high temperatures below normal
in the low/mid 60s. These cool conditions and mostly clear skies
will persist into Monday night with even cooler overnight low
temperatures in the upper 30s to mid 40s.
Tuesday through Saturday...
Tuesday will have mostly sunny skies and highs in the upper 60s,
with lows dropping into the upper 40s Tuesday night. The surface
high pressure aiding in these mild conditions will move southeast of
the area late evening, allowing winds to veer to the south by Wednesday
morning. This warm air advection will push highs into the lower
70s, before another system pushes into the area bringing chances for
precipitation every day for the rest of the period.
Models are still inconsistent with the handling this next system,
but agree with the previous forecast that the ECMWF solution seems
more reasonable. An upper-level wave will move NE into the central
plains by late Thursday bringing the best chances for thunderstorms
Wednesday night though Thursday night. Severe potential is still
low as the best CAPE/shear seems to be south or west of our area,
depending on the model. From here, thunderstorm chances remain until
Saturday, but confidence in timing and the overall pattern are
low.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1153 PM CDT SAT MAY 9 2015
MVFR stratus lingering in the area and trends suggest more
persistent and lower cigs are likely through the next several
hours. Weak inversion should keep stratus in place through 15-17Z.
Caveat continues to be convection chances. At least some chance
remains even well ahead of dryline as moisture streams north but
again confidence too low for any early inclusion.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Heller/Hennecke
AVIATION...65
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW
WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME
THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS
WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST
UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN
EVENING AT IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 AM EDT SUN MAY 10 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM EDT SAT MAY 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG
THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY
TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM
PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL
LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4
CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST
AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY
SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE
FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER
MI WHERE STRONGEST UPSLOPE IS OCCURRING.
FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND
THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA
WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES.
OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE
HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS
FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS
DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL
FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE
FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST
WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A
RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT...
ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES
ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD.
TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF
LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE
AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE
FLOW CONTINUES.
IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE
A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE
TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH
SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM
MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING
CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF
THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP
LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA
COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS
REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC
POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST...
RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR...
50S INLAND. MAY REACH 60F IN A FEW SPOTS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW
WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME
THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS
WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST
UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN
EVENING AT IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT SAT MAY 9 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE
NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND
LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL
BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL
BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL
CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL
ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER
PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND
THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE
LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS.
ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT
SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO
E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS THRU THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT SUN MAY 10 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM EDT SAT MAY 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG
THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY
TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM
PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL
LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4
CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST
AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY
SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE
FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER
MI WHERE STRONGEST UPSLOPE IS OCCURRING.
FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND
THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA
WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES.
OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE
HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS
FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS
DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL
FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE
FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST
WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A
RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT...
ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES
ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD.
TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF
LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE
AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE
FLOW CONTINUES.
IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE
A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE
TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH
SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM
MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING
CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF
THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP
LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA
COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS
REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC
POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST...
RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR...
50S INLAND. MAY REACH 60F IN A FEW SPOTS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM EDT SAT MAY 9 2015
RAIN ASSOCIATED WITH AN UPPER SHORTWAVE AND SFC LOW WILL MOVE INTO
THE AREA FROM THE SW SUN NIGHT AND CONTINUE INTO MON. AS THE SFC LOW
SHIFTS ACROSS THE AREA MON EVENING INTO MON NIGHT...SHIFTING A DRY
SLOT ACROSS MOST OF THE CWA. THIS WILL DIMINISH THE RAIN UNTIL
MOISTURE MOVES BACK IN FROM THE W ON THE BACK SIDE OF THE SYSTEM
LATE MON NIGHT INTO TUE. MUCH COLDER AIR SURGES IN ON TUE WITH 850MB
TEMPS DROPPING TO AROUND -15C OVER AT LEAST NWRN UPPER MI BY 00Z
WED. THIS WILL SUPPORT A CHANGE OVER TO MIXED PRECIP OVER THE
NRN/NWRN PORTIONS OF UPPER MI ON TUE AND MOSTLY SNOW TUE NIGHT. THE
FORCING TUE INTO TUE NIGHT WILL COME FROM BOTH THE WRAP AROUND FROM
THE LOW AND FROM A WEAK SHORTWAVE MOVING IN FROM THE NW...WITH ONLY
LIGHT PRECIP EXPECTED AND LITTLE TO NO SNOW ACCUMULATION.
MON WILL SEE HIGHS IN THE 50S INLAND FROM LAKE SUPERIOR AND IN THE
40S ALONG THE BIG LAKE. TUE LOOKS TO BE THE COLDEST DAY OF THE WEEK
WITH HIGHS BARELY REACHING 50F OVER THE SCENTRAL AND IN THE 40S
ELSEWHERE. IT WILL ALSO BE CLOUDY AND BREEZY MAKING IT FEEL EVEN
COLDER. TEMPS WILL BE TRICKY TUE NIGHT AS CLOUDS WILL BE CLEARING
AND THE COLDER AIRMASS REMAINS. SHOULD SEE LOWS NEAR OR BELOW
FREEZING WITH THE CURRENT EXPECTATION OF CLOUDS CLEARING BY SUNRISE
WED...BUT MUCH COLDER TEMPS ARE POSSIBLE IF THE CLOUDS CLEAR EARLIER.
THE AIRMASS WILL BEGIN TO MODERATE ON WED AS 850MB TEMPS INCREASE TO
AROUND 0C BY 00Z THU WITH A 1031MB SFC HIGH MOVING OVER THE CWA.
SHOULD BE AN OVERALL PLEASANT DAY WITH SUNNY SKIES...LIGHT WINDS AND
HIGHS IN THE 50S INLAND TO UPPER 40S RIGHT ALONG LAKE SUPERIOR.
SIGNIFICANT UNCERTAINTY EXISTS IN THE THU-SAT PORTION OF THE
FORECAST AS MODELS CONTINUITY AND AGREEMENT IS POOR. THE GENERAL
IDEA IS UPPER RIDGING BUILDING INTO OR NEAR THE REGION...PROMOTING
WARMER TEMPS. RAIN CAN NOT BE RULED OUT. LET CONSENSUS OF GUIDANCE
HANDLE THIS PART OF THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW
WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME
THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS
WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST
UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN
EVENING AT IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT SAT MAY 9 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE
NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND
LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL
BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL
BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL
CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL
ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER
PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND
THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE
LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS.
ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT
SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO
E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS THRU THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
357 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 357 AM CDT SUN MAY 10 2015
WINDY AND COOLER TODAY WITH RAIN ON THE WAY. GENERALLY HAVE SLOWED
DOWN ONSET OF PRECIPITATION DUE TO THE MUCH DRIER THAN ORIGINALLY
ANTICIPATED AIR ACROSS THE REGION...BUT RAINFALL WILL INDEED SPREAD
ACROSS THE ENTIRE REGION BY THIS EVENING. MOST RAIN WILL FALL
OVERNIGHT TONIGHT...BUT CONTINUE THROUGH MONDAY. TOTAL RAINFALL
VALUES UP TO AN INCH OR SO ACROSS MUCH OF NORTHEAST MINNESOTA
THROUGH MONDAY EVENING...WITH LESSER AMOUNTS OF A QUARTER INCH TO A
HALF INCH OVER MOST OF NORTHWEST WISCONSIN. THERE IS STILL A CHANCE
FOR A FEW RUMBLES OF THUNDER TONIGHT...BUT WIDESPREAD THUNDERSTORMS
ARE NOT EXPECTED WITH THIS SYSTEM.
ON THE SYNOPTIC SCALE A VERY DYNAMIC PATTERN ACROSS THE NATIONS
MID-SECTION WITH AN UPPER LEVEL LOW OVER NORTHEAST COLORADO MOVING
NORTH INTO THE CENTRAL/NORTHERN PLAINS TODAY INTO TOMORROW. THE
ASSOCIATED SURFACE LOW OVER THE CENTRAL PLAINS WILL MOVE
NORTH-NORTHEAST INTO SOUTHERN MINNESOTA BY MONDAY MORNING...THEN
GRADUALLY WEAKEN AND MOVE EAST. WHILE THERE IS SOME LIGHT PRECIP
ONGOING THIS MORNING ACROSS THE BORDERLAND REGION DUE TO THE
ENTRANCE REGION OF THE H3 JET...THE MAIN EVENT WILL GRADUALLY ARRIVE
LATE TODAY AND REALLY INTENSIFY OVERNIGHT TONIGHT. NOSE OF A 100KT
H3 JET ASSOCIATED WITH THE UPPER LOW WILL MOVE INTO THE REGION THIS
EVENING...WITH THE BEST MID-LEVEL PVA ARRIVING TOWARDS MIDNIGHT AS
THE H5 LOW MOVES INTO THE CENTRAL/EASTERN DAKOTAS. WHILE THE SFC LOW
WILL JUST GRAZE THE SOUTHERN EDGE OF THE CWA ON MONDAY...THE
INCREASED PRESSURE GRADIENT CAUSED BY THE SFC LOW AND A STUBBORN
HIGH OVER NORTHERN MANITOBA/NORTHWEST ONTARIO WILL LEAD TO STRONG
EASTERLY WINDS TODAY INTO TOMORROW.
TODAY...CLOUDY AND WINDY...ESPECIALLY FROM THE TWIN PORTS WEST TO
THE BRAINERD LAKES REGION. LIGHT RAIN SHOWERS WILL GRADUALLY FROM
SOUTHWEST TO NORTHEAST. DO NOT EXPECT A STEADY RAIN TO DEVELOP JUST
YET...JUST SOME OFF AND ON LIGHT RAIN THROUGH THE DAY. WINDS WILL BE
THE MAIN STORY WITH GUSTY EAST-NORTHEASTERLY WINDS OF 10 TO 20 MPH
AND GUSTS UP TO 35 MPH OR SO. STRONGEST WINDS WILL BE IN THE TWIN
PORTS REGION WHERE A FEW GUSTS APPROACHING 45 MPH CANNOT BE RULED
OUT. HIGH TEMPERATURES WILL BE COOLER...IN THE LOW 40S BY LAKE
SUPERIOR TO THE LOW 50S IN NORTH CENTRAL MINNESOTA. WHILE COAST
WISCONSIN WILL BE LIMITED TO THE MID 40S TO LOW 50S...FURTHER INLAND
SUCH AS SAWYER AND PRICE COUNTY WILL WARM UP TO THE LOW 60S DUE TO A
COMBINATION OF LOW LEVEL WARM AIR ADVECTION AND DELAYED ONSET OF
THICK CLOUD COVER.
TONIGHT...RAIN...HEAVY AT TIMES. A FEW RUMBLES OF THUNDER DUE TO
ELEVATED CONVECTION MAINLY SOUTH OF HIGHWAY 2. SOME SNOW MAY MIX IN
ACROSS THE TIP OF THE ARROWHEAD AND ELSEWHERE ACROSS THE
REGION...BUT NO SNOW ACCUMULATION IS EXPECTED OVERNIGHT. EAST WINDS
WILL REMAIN WINDY AT 10 TO 20 MPH...STRONGEST ALONG THE COAST OF
LAKE SUPERIOR AND ESPECIALLY UP THE NORTH SHORE WHERE GUSTS TO 30
MPH CAN BE EXPECTED OVERNIGHT. TOTAL OVERNIGHT RAINFALL AMOUNTS OF A
HALF INCH TO THREE QUARTERS OF AN INCH...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. TEMPERATURES FALLING TO THE MID TO UPPER 30S.
MONDAY...OFF AND ON RAIN CONTINUES. COOL WITH WINDS GRADUALLY
DECREASING. A DRY SLOT MAY WORK ITS WAY INTO THE INTERSTATE 35
CORRIDOR EAST ACROSS NORTHWEST WISCONSIN AND WINDS WILL TURN TO
BECOME OUT OF THE NORTHEAST AS THE SFC LOW MOVES EAST. TOTAL
RAINFALL THROUGH THE DAYTIME PERIOD /7AM TO 7PM/ AROUND A QUARTER TO
HALF INCH...POTENTIALLY LOWER IN AREAS SOUTH OF HIGHWAY 2 IF DRY
SLOT BUILDS IN EARLIER THAN ANTICIPATED. HIGHS COOLER AS COLD AIR
MOVES IN BEHIND THE LOW...IN THE LOW 40S ACROSS NORTHEAST MINNESOTA
AND INTO THE MID 50S TO NEAR 60S ACROSS PARTS OF NORTHWEST WISCONSIN.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 357 AM CDT SUN MAY 10 2015
MONDAY NIGHT AND TUESDAY THE SPRING STORM SYSTEM WILL SLOWLY MOVE
EAST OF THE AREA...WITH AN AREA OF FRONTOGENESIS THAT WILL AFFECT
MUCH OF THE FORECAST AREA MONDAY NIGHT AND EARLY TUESDAY. AT THIS
TIME...THE SYSTEM WILL BE PULLING COLDER AIR INTO NORTHERN MINNESOTA
FROM THE NORTH...WITH 850MB TEMPERATURES DROPPING TO AROUND -4 BY
TUESDAY MORNING. SURFACE TEMPERATURES WILL ALSO BE DOWN IN THE LOW
TO MID 30S...MAKING ACCUMULATING SNOW A REAL POSSIBILITY WITH THIS
SYSTEM. HOWEVER...THE RAINFALL THAT WILL COME BEFORE IT AND THE
RELATIVELY WARM SUBSOIL TEMPERATURES IN THE LOW 40S ARE GOING TO
CAUSE THE SNOW TO DO A LOT OF MELTING AS SOON AS IT HITS THE
GROUND...AND IS UNLIKELY TO LAST PAST NOON TUESDAY. AN INCH OR TWO
OF SNOW MAY FALL...BUT DUE TO MELTING AND COMPACTION WE ARE UNLIKELY
TO SEE MORE THAN AN INCH OF SNOW ON THE GROUND AT ANY TIME. WOULD
BE A LOT MORE EXCITED ABOUT SNOWFALL ACCUMULATIONS IF THE STRONG
FORCING WE SEE EARLIER IN THIS SYSTEM WERE TO OVERLAP WITH THE COLD
TEMPERATURES.
QUIETER CONDITIONS RETURN FOR TUESDAY NIGHT AND EARLY WEDNESDAY AS A
RIDGE OF HIGH PRESSURE BUILDS ACROSS THE AREA. WITH THE COLD AIR
BEHIND THE RETREATING LOW PRESSURE SYSTEM...TUESDAY NIGHT COULD BE
PRETTY COLD...WITH MINS IN THE LOW 30S AND EVEN UPPER 20S FOR A
LARGE PORTION OF THE FORECAST AREA. WE ARE STILL GETTING FREEZING
TEMPERATURES OFTEN ENOUGH...WE HAD TWO NIGHTS OF NEAR OR BELOW
FREEZING JUST 5-6 DAYS AGO...THAT WE ARE UNLIKELY TO BE ISSUING ANY
FROST/FREEZE HEADLINES FOR THIS EVENT.
ANOTHER STRONG SPRING STORM SYSTEM IS EXPECTED TO MOVE ACROSS THE
MIDWEST WEDNESDAY THROUGH FRIDAY...WITH MAINLY RAIN EXPECTED THROUGH
THE PERIOD. TEMPERATURES TO START OUT AS FAIRLY COOL WITH HIGHS
NEAR TO BELOW NORMAL WEDNESDAY...GRADUALLY WARMING TO ABOVE NORMAL
BY FRIDAY AS THE SYSTEM ADVECTS MORE WARM AIR INTO THE AREA THROUGH
THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1227 AM CDT SUN MAY 10 2015
AN AREA OF LOW PRESSURE WILL TRACK NORTHEASTWARDS TONIGHT FROM
EASTERN COLORADO THROUGH NEBRASKA...AND INTO SOUTHWEST MINNESOTA BY
MONDAY MORNING. DURING THIS TIMEFRAME HIGH PRESSURE WILL BUILD
OVER NORTHERN ONTARIO. AS A RESULT A TIGHT PRESSURE GRADIENT WILL
DEVELOP OVER THE FORECAST AREA...WHICH WILL RESULT IN GUSTY EASTERLY
AND NORTHEASTERLY WINDS. GUSTY CONDITIONS ARE EXPECTED TO PERSIST
THROUGH MONDAY WITH THE HIGHEST GUSTS APPROACHING 40 KTS AT KDLH.
LATEST 00Z GUIDANCE AND HRRR TRENDS SHOW PRECIPITATION MOVE IN THE
VICINITY OF KINL. AS A RESULT...BROUGHT VCSH INTO KINL BETWEEN
11Z-16Z.
EXPECT PRECIPITATION ASSOCIATED WITH THE WARM FRONT FROM THE LOW TO
MOVE IN BETWEEN 18Z AND 01Z...AFFECTING THE KBRD SITE FIRST AND
SPREADING NORTHEASTWARDS TO OTHER TERMINALS. VFR CONDITIONS EXPECTED
AT KHYR AND KINL THROUGH THE FORECAST PERIOD...HOWEVER MVFR CIGS
POSSIBLE AT KHYR AFTER 02Z...BUT NOT CONFIDENT DUE TO DRIER AIR IN
LOWER LEVELS. ALL OTHER TERMINALS WILL SEE MVFR CONDITIONS DEVELOP
BETWEEN 22Z-01Z. KDLH AND KHIB MAY SEE IFR CIGS LATE IN THE
PERIOD...BUT NOT CONFIDENT ON THE TIMING. KBRD WILL SEE IFR CIGS
DEVELOP 01Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 43 38 40 35 / 50 100 70 70
INL 52 36 39 33 / 30 100 90 70
BRD 49 40 49 36 / 50 100 70 60
HYR 57 45 57 35 / 20 90 60 60
ASX 44 37 45 35 / 40 90 70 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ143>147.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM CDT TUESDAY FOR
LSZ121-140>148.
&&
$$
SHORT TERM...JJM
LONG TERM...LE
AVIATION...WL/LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1227 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1227 AM CDT SUN MAY 10 2015
UPDATED AVIATION SECTION BELOW.
UPDATE ISSUED AT 1010 PM CDT SAT MAY 9 2015
LOWERED MIN TEMPS ALONG THE NORTH SHORE A FEW DEGREES AS COLDER
AIR FROM LAKE SUPERIOR IS AFFECTING THE AREA. REST OF THE FORECAST
ON TRACK.
UPDATE ISSUED AT 717 PM CDT SAT MAY 9 2015
MADE SOME ADJUSTMENTS TO CLOUD COVER WITH LARGE AREA OF CLEAR SKY
IN NW WI AT 00Z. DELAYED THE ONSET OF THE PCPN UNTIL AFTER 12Z
SUNDAY PER THE LATEST SHORT TERM HRRR AND RAP. REST OF THE
FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
HIGH PRESSURE OVER SOUTHERN CANADA WILL CONTINUE TO GIVE THE
NORTHLAND DRY NORTH TO NE FLOW THROUGH TONIGHT. A STUBBORN LOW
LEVEL CLOUD DECK OVER NE MINNESOTA WILL SLOWLY SCATTER OUT THROUGH
THE REST OF THE THIS AFTERNOON AND EARLY THIS EVENING. THE CLOUD
DECK HAS BEEN SLOW TO ERODE BECAUSE OF THE LACK OF WIND TO MIX IT
OUT...BUT NW WISCONSIN HAS CLEARED OUT DUE TO STRONGER WINDS
COMING OFF OF LAKE SUPERIOR.
A LOW PRESSURE SYSTEM IN EASTERN COLORADO WILL MOVE INTO THE
CENTRAL PLAINS TONIGHT AND SUNDAY ON TRACK TOWARDS MINNESOTA. THIS
SYSTEM WILL BRING INCREASING MID LEVEL MOISTURE INTO THE UPPER
MIDWEST AND EVENTUALLY RAINS. IT WILL TAKE SOME TIME FOR THE LOW
LEVELS DUE TO THE THE RELATIVELY DRY FLOW FROM CANADA...SO THIS
MEANS IT WILL TAKE SOME TIME FOR THE RAINS TO MOVE INTO THE
REGION. THE GFS/NAM/SREF/GEM/ECMWF MODELS DRASTICALLY DELAYED THE
TIMING WITH WHICH THE PCPN MOVES INTO THE NORTHLAND...SO REFLECTED
THIS IN THE LATEST FORECAST.
SUNDAY IS MAINLY EXPECTED TO BE A COOL AND WINDY DAY. THERE WILL
BE INCREASING ENE WINDS WITH THE STRONGEST WINDS DOWNWIND OF LAKE
SUPERIOR...WHERE GUSTS OF 25 TO 35 MPH ARE POSSIBLE. TEMPERATURES
WILL ONLY REACH THE LOWER 40S NEAR LAKE SUPERIOR...BUT MORE INLAND
AREAS SHOULD REACH THE 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
FOCUS IN EXTENDED ON THE COOL TEMPERATURES AND SNOW CHANCES AS A
CUT OFF LOW TRACKS OUT OF THE DAKOTAS SUNDAY NIGHT...AND MIGRATES
SLOWLY ACROSS MINNESOTA/WESTERN LAKE SUPERIOR MONDAY/MONDAY
NIGHT.
THE LOW WILL BRING A PROLONGED PERIODS OF RAIN...AND ISOLATED
THUNDER. HAVE CONTINUED TO CARRY HIGH/DEFINITE POPS SUNDAY NIGHT
THROUGH MONDAY NIGHT. AT THIS TIME...THE HEAVIEST RAINFALL IS
EXPECTED ACROSS THE IRON RANGE/ARROWHEAD REGION OF NORTHEAST
MN...WITH TOTALS THROUGH TUESDAY OF AROUND INCH.
MODELS ARE IN GOOD AGREEMENT THAT BELOW ZERO H85 TEMPS WRAP
AROUND THE BACK SIDE OF THE LOW MONDAY...SPREADING OVER THE
NORTHLAND MONDAY NIGHT AND TUESDAY. THIS WILL BRING A CHANCE OF
SNOW OR A RAIN/SNOW MIX FOR THE MONDAY NIGHT AND TUESDAY PERIODS.
LATEST NAM/GFS BUFR SOUNDINGS AT KELO AND KHIB SHOW DEEPLY
SATURATED LOW AND MID LEVELS...PWATS AROUND 3/4 OF AN INCH...AND
TEMP PROFILES JUST ABOVE THE SFC REMAINING WELL BELOW THE ZERO
ISOTHERM. ALTHOUGH A PERIOD OF SNOW IS EXPECTED...AND SOME
ACCUMULATION WILL BE POSSIBLE IN THE MN ARROWHEAD/SOUTH SHORE
REGION...MOST LOCATIONS CAN EXPECT THE SNOW TO MELT AS IT REACHES
THE GROUND WITH ONLY ACCUMULATION ON ELEVATED SURFACES.
HAVE INCREASED POPS TUESDAY ABOVE THE SUPERBLEND GUIDANCE AS
STEEP LAPSE RATES...AROUND 100 J/KG OF CAPE...AND WRAP AROUND
MOISTURE WILL SUPPORT A TYPICAL POST-LOW DAY OF INSTABILITY
SHOWERS. THE SHOWERS WILL LIKELY MIX WITH SNOW DURING THE MORNING
HOURS...CHANGING TO ALL RAIN IN THE AFTERNOON...WITH LIGHT QPF ON
THE ORDER OF A FEW HUNDREDTHS. THE EXCEPTION IS ALONG THE GOGEBIC
RANGE IN NRN WISCONSIN WHERE TEMPERATURES WILL BE COOLER AND THE
RAIN/SNOW MIX MAY PERSIST THROUGH THE EVENING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1227 AM CDT SUN MAY 10 2015
AN AREA OF LOW PRESSURE WILL TRACK NORTHEASTWARDS TONIGHT FROM
EASTERN COLORADO THROUGH NEBRASKA...AND INTO SOUTHWEST MINNESOTA BY
MONDAY MORNING. DURING THIS TIMEFRAME HIGH PRESSURE WILL BUILD
OVER NORTHERN ONTARIO. AS A RESULT A TIGHT PRESSURE GRADIENT WILL
DEVELOP OVER THE FORECAST AREA...WHICH WILL RESULT IN GUSTY EASTERLY
AND NORTHEASTERLY WINDS. GUSTY CONDITIONS ARE EXPECTED TO PERSIST
THROUGH MONDAY WITH THE HIGHEST GUSTS APPROACHING 40 KTS AT KDLH.
LATEST 00Z GUIDANCE AND HRRR TRENDS SHOW PRECIPITATION MOVE IN THE
VICINITY OF KINL. AS A RESULT...BROUGHT VCSH INTO KINL BETWEEN
11Z-16Z.
EXPECT PRECIPITATION ASSOCIATED WITH THE WARM FRONT FROM THE LOW TO
MOVE IN BETWEEN 18Z AND 01Z...AFFECTING THE KBRD SITE FIRST AND
SPREADING NORTHEASTWARDS TO OTHER TERMINALS. VFR CONDITIONS EXPECTED
AT KHYR AND KINL THROUGH THE FORECAST PERIOD...HOWEVER MVFR CIGS
POSSIBLE AT KHYR AFTER 02Z...BUT NOT CONFIDENT DUE TO DRIER AIR IN
LOWER LEVELS. ALL OTHER TERMINALS WILL SEE MVFR CONDITIONS DEVELOP
BETWEEN 22Z-01Z. KDLH AND KHIB MAY SEE IFR CIGS LATE IN THE
PERIOD...BUT NOT CONFIDENT ON THE TIMING. KBRD WILL SEE IFR CIGS
DEVELOP 01Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 38 41 36 47 / 100 80 70 40
INL 37 40 34 50 / 80 90 70 40
BRD 39 49 37 52 / 90 70 60 30
HYR 45 54 35 48 / 90 60 60 50
ASX 40 41 35 43 / 80 70 60 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...GALE WARNING FROM 10 AM THIS MORNING TO 7 PM CDT MONDAY FOR
LSZ121-140>148.
&&
$$
UPDATE...LE/GSF/GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...GRANING
AVIATION...WL/LE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
355 AM CDT Sun May 10 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 355 AM CDT Sun May 10 2015
Warm front just north of the I-70 corridor will continue advancing
slowly northward this morning and should be well north of the
forecast area into Iowa and northern Illinois by 17-18Z. Deep
moisture combined with another passing MCV and low level warm
advection will continue to produce scattered showers and the
occasional thunderstorm this morning. The primary shortwave over
northeast Colorado is finally moving, opening up, and being drawn up
into the mean flow. Should see the surface low associated with the
wave tighten up and move from western Kansas into northeast Nebraska
or northwest Iowa by early evening. Short range guidance suggests
there will be another wave of rain and thunderstorms this afternoon
well ahead of the cold front, probably triggered by another MCV
generated by the convection now occurring over central Texas. NAM
and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm
sector across the area for this MCV to work with. Add in 40+ kts of
0-6km shear and severe thunderstorms look more likely today than the
past couple of days. Not sure what the mode of thunderstorm
development will ultimately be, but would a few discrete rotating
storms will be possible before everything congeals into clusters or
broken lines.
Carney
.LONG TERM: (Tonight through Saturday)
Issued at 355 AM CDT Sun May 10 2015
Southwest flow aloft will persist for much of this period, only
ending when the main TROF ejects thru our region. Thrown into the
mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system currently over the central High Plains. This will yield high
PoPs thru Monday.
Severe storm potential still on track today and tonight, with the
best timeframe from mid-afternoon into mid-evening as better bulk
shear enters the fray during this time and there should still be
enough instability to create the conditional risk with a good
synoptic signal to also trigger widespread convection intiation from
the west with this beginning entering our CWA during this time. The
highest risk locations in our CWA will be to the west of STL
metro--in northeast and central MO. Outside of these locations and
times, this does not necessarily preclude severe wx occurrence.
Monday continues to look marginal on severe for our area, with the
highest risk locations being where the surface cold front will be as
things start to heat up for the day and this should be just east of
STL metro. The best timeframe for our CWA is a bit more sped
up--late morning and early afternoon--and this accounts for SPC`s
push of the main severe threat further east.
A localized heavy rainfall threat also continues thru Monday in this
favorable synoptic pattern, and indeed, localized heavy rainfall has
already occurred in spots scattered across our CWA, with these spots
rather small in coverage and between 2-3" over a 3-day period. No
FFA issuance with this package but the beginnings of a clearer
signal and focus are coming into play tonight and Monday morning to
perhaps justify one eventually but would like to see a bit more
favorable antecedent conditions (i.e. more rainfall today) before
this occurs as current QPF not enough to make up for this.
Preferred the higher MOS temps on Monday with SW flow and what
should be afternoon clearing, but if the rain and thicker clouds are
slower to exit, will need to chop the temps down by about 5 degrees.
For Tuesday and Wednesday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. The much
drier column and lack of upper level disturbances or surface fronts
will give us a rare two-day dry period. Temps should actually be a
bit below average with cool nighttime mins in the 40s.
The RIDGE aloft on Thursday will then gradually transition back to
an active SW flow aloft pattern for next weekend. While there
remain model discrepancies during this period, it looks to be one
where at least Climo PoPs [25-30%] are justified and more with
general agreement on moisture return and lifting mechanisms. Temps
will make a return back to average or even above average during this
time.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1153 PM CDT Sat May 9 2015
Band of light SHRA will continue moving nwd, but continue to break
up and may not reach UIN, those shud reach STL/SUS/CPS. FG may
develop tonight, but with extensive cloud cover across the region,
do not anticipate anything below MVFR. Expect most of Sun to be
dry with TSRA approaching the region during the late afternoon
into evening hours.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1212 AM CDT Sun May 10 2015
.SHORT TERM...(This Evening through Sunday)
Issued at 305 PM CDT SAT MAY 9 2015
Thunderstorm chances will increase through this evening and tonight
as a 50-60kt low level jet sets up along the MO/KS border and
overruns the stationary boundary near the I-44 corridor. Large
amounts of more moist air will spread into the region ahead of a
shortwave trough currently over central OK. Short term forecast
progs show K-index values around 40, well over the baseline of 30
generally needed for heavy rainfall. We`re also seeing tall and
skinny CAPE on RUC forecast soundings. With fairly saturated soils
from previous two nights of rainfall, will be issuing a Flash
Flood Watch for areas along and west of an Osceola to Cassville to
Gainesville line through 1 AM Monday. Later shifts may need to
modify areal coverage and timing.
Severe storm threat will remain on the lower end for hail and
straight line winds, but not zero. Better instability and more
favorable vertical wind shear for rotating storms will remain to our
west, in closer proximity to the main upper low pressure system over
the four corners region.
With better instability and upper level dynamics ahead of the
upper low which finally ejects to the northeast into the central Plains,
severe threat will be higher on Sunday afternoon/evening.
.LONG TERM...(Sunday Night through Saturday)
Issued at 305 PM CDT SAT MAY 9 2015
As the upper low continues to shift northward into the upper
Midwest, a cold front will finally push east of the region Monday
morning and bring a much drier and slightly cooler air mass into
the MO Ozarks/SE KS. We may see a few lingering showers over our
far eastern counties, so will keep storms in the forecast east of a
Warsaw to Cassville line through the morning, and east of a Rolla
to Gainesville line through the afternoon.
Surface high pressure will remain over the region through
Wednesday before another lee side trough sets up over the southern
Rockies ahead of an upper low moving into the southern CA coast
late next week. So expect increasingly stormy conditions from late
next week into the weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1203 AM CDT SUN MAY 10 2015
For the KSGF/KJLN/KBBG tafs: Periods of showers and tstms will
occur during the taf period. Hard to pinpoint timing but used a
mix of the high resolution models and then increased chances for
precip late in the taf period with the approach of a sfc front.
Expect a period of MVFR/IFR conditions at times with lower ceilings
and/or fog toward 12z and with any heavier showers.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH through late tonight FOR MOZ066-067-077-078-
088-089-093>095-101>105.
KS...FLASH FLOOD WATCH through late tonight FOR KSZ073-097-101.
&&
$$
SHORT TERM...Terry
LONG TERM...Terry
AVIATION...DSA
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
350 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
...LOCATION OF SEVERE STORMS TODAY IS THE MAIN CHALLENGE...
EXCEPTIONALLY ACTIVE/DYNAMIC PATTERN CONTINUES OVER THE CENTRAL
UNITED STATES TODAY AS LARGE UPPER LOW SPINS OVER THE HIGH PLAINS.
WATER VAPOR IMAGERY SHOWED THE CLOSED AND WRAPPED UP CIRCULATION
DRIFTING NORTHEAST AROUND 30 KNOTS...OUT OF NORTHEAST COLORADO
AND HEADED FOR NORTHWEST NEBRASKA THIS MORNING.
A COMPLEX AND HIGHLY BAROCLINIC SURFACE PATTERN WAS ANALYZED AT
06Z WITH A CLOSED 1004MB LOW NEAR THE KANSAS-COLORADO BORDER AND A
TIGHT THERMAL AND PRESSURE GRADIENT NORTH OF THE LOW. WARM FRONT
EXTENDED FROM THE LOW EASTWARD WITH LOW TO MID 60S DEW POINTS OVER
KANSAS...AND AN INVERTED TROF EXTENDED NORTHEAST INTO THE SIOUX
CITY AREA. AIRMASS NORTH OF THE LOW WAS COLD ENOUGH FOR WIDESPREAD
SNOW IN THE WESTERN HIGH PLAINS THIS MORNING.
AS THIS PATTERN EVOLVES THROUGHOUT THE DAY...THE FEATURES BY MID-
LATE AFTERNOON APPEAR TO BE SETTING UP FOR A NEARLY CLASSIC
LOOKING COLD CORE SUPERCELL OUTBREAK. UNFORTUNATELY THERE ARE
SMALL BUT IMPORTANT DIFFERENCES IN THE SUITE OF MODEL SOLUTIONS
REGARDING WHERE THE UPPER AND SURFACE LOWS WILL TRACK...AND THESE
DIFFERENCES COULD RESULT IN THE LOCATION OF THE SUPERCELLS VARYING
BY SEVERAL COUNTIES DEPENDING ON THE SOLUTION.
THE CONSENSUS SOLUTION OF THE SREF MEAN FOR THE PLACEMENT/TRACK
OF THE UPPER AND SURFACE LOWS IS SIMILAR TO THE GOING FORECAST AS
WELL AS CURRENT TRAJECTORIES OF THE UPPER LOW. USING THE SREF MEAN
SOLUTION...THE FORECAST PATTERN IN THE 18-21Z TIME FRAME INCLUDES
THE FOLLOWING INGREDIENTS TO SUPPORT SUPERCELLS OVER NORTHEAST
NEBRASKA AND WEST CENTRAL IOWA: UPPER LOW OVER WESTERN NEBRASKA
WITH 500 MB TEMPERATURES AROUND -19C... TRIPLE POINT AND DEEP
SURFACE LOW NEAR O`NEILL...100+ KNOT UPPER LEVEL JET OVER EASTERN
NEBRASKA...WELL PRONOUNCED DRY SLOT OVER EASTERN NEBRASKA WHICH
WILL SUPPORT ML CAPE VALUES EXCEEDING 1200 J/KG AND A DIFFERENTIAL
THERMAL BOUNDARY ON THE EASTERN EDGE OF THE DRY SLOT... AND 0-1KM
SHEAR VALUES AT OR ABOVE 20 KNOTS.
HOWEVER...NUMEROUS FACTORS INCREASE THE UNCERTAINTY IN THESE
SCENARIOS INCLUDING THE ABOVE MENTIONED SPREAD IN MODEL SOLUTIONS.
IF THE MODELS DISPLAYING A NORTHERN TREND ARE CORRECT...MUCH OF
THE FORECAST AREA WOULD BE DRY AND SUNNY UNDER THE DRY SLOT WITH
THE STRONG STORM DEVELOPMENT NORTH OF THE AREA. IF THE SOUTHERN
SOLUTIONS ARE CORRECT...THE STORMS COULD DEVELOP AS FAR SOUTH AS
INTERSTATE 80 AND TRACK NORTH THROUGHOUT THE AFTERNOON. THE
FORECAST PROBABILITY OF STORMS WILL BE A FUNCTION OF THE
DISTRIBUTION OF THESE MODEL SOLUTIONS. THE MOST LIKELY AREA FOR
SEVERE STORMS WILL BE THE FAR NORTHEAST CORNER OF NEBRASKA AND
WEST CENTRAL IOWA...WITH A CHANCE FOR SEVERE STORMS EXTENDING
SOUTH TO INTERSTATE 80.
LATEST OPERATIONAL HRRR SOLUTIONS SUPPORT THUNDERSTORM
DEVELOPMENT BY EARLY AFTERNOON AND JUST EAST OF THE MISSOURI
RIVER.
THE STORMS AND SHOWERS SHOULD EXIT THE FORECAST AREA BY EVENING.
LOW AMPLITUDE UPPER RIDGING AND SURFACE HIGH PRESSURE BUILDS INTO
THE PLAINS MONDAY-TUESDAY WITH COOL BUT DRY WEATHER EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
THE UPPER PATTERN RETURNS TO BROAD SCALE TROFFING OVER THE WESTERN
US AND PACIFIC COASTAL AREAS WITH SHORTWAVES ONCE AGAIN RETURNING
TO THE PLAINS. AFTER THE DRY BEGINNING OF THE WEEK...GOOD CHANCES
FOR RAIN AND THUNDERSTORMS RETURN FOR THE PERIOD BEGINNING
WEDNESDAY NIGHT AND PERSISTING INTO THE WEEKEND.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1138 PM CDT SAT MAY 9 2015
MVFR CEILINGS WILL OVERTAKE ALL TAF SITES TONIGHT...AND SHOWERS
SHOULD BE INCREASING IN COVERAGE AND SHOULD REACH TAF SITES LATER
TONIGHT AS WELL. WITH LOW CONFIDENCE IN COVERAGE OF THUNDER...HAVE
OPTED TO NOT MENTION AT KOFK AND BRING IN A TEMPO FOR AN HOUR AT
KOMA/KLNK. OVERNIGHT ACTIVITY WILL CLEAR SITES IN THE
MORNING...LEAVING A GAP BETWEEN THAT ACTIVITY AND POTENTIAL
SHOWERS/STORMS THIS AFTERNOON. AFTERNOON SHOWERS/STORMS SHOULD BE
PRETTY ISOLATED TO SCATTERED IN COVERAGE...ESPECIALLY AT KLNK
WHERE CONFIDENCE IN SEEING SHOWERS/STORMS IS LOWEST. HAVE KEPT
JUST A SHORT PERIOD OF VCSH AT ALL SITES UNTIL CONFIDENCE
INCREASES...FOLLOWED BY WINDS VEERING TO WESTERLY AND INCREASING.
MODELS HINT AT LOWER CEILINGS COMING IN BEHIND THE FRONT LATE IN
THE TAF PERIOD...AND HAVE INTRODUCED POTENTIAL AT KOFK/KOMA.
&&
.HYDROLOGY...
ISSUED AT 350 AM CDT SUN MAY 10 2015
FLOODING CONTINUES IN SOUTHEAST NEBRASKA MAINLY ALONG THE BIG BLUE
RIVER. FORTUNATELY THIS AREA IS NOT EXPECTED TO RECEIVE
SIGNIFICANT RAINFALL OVER THE NEXT FEW DAYS...THEREFORE THE RIVER
LEVELS SHOULD CONTINUE TO FALL AS PREDICTED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...NIETFELD
LONG TERM...NIETFELD
AVIATION...MAYES
HYDROLOGY...NIETFELD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1132 PM CDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
TONIGHT AND TOMORROW...FORECASTING CONCERNS CENTER ON
THE SEVERE THREAT THIS EVENING...SNOW THREAT IN THE WEST AND
NORTHWEST OVERNIGHT TONIGHT AND SUNDAY...AS WELL AS THE THREAT FOR
HEAVY RAIN AND POSSIBLE FLASH FLOODING CONCERNS. A VIGOROUS UPPER
LEVEL LOW...CURRENTLY OVER SOUTH CENTRAL COLORADO...WILL MIGRATE
INTO NORTHEASTERN COLORADO THROUGH 12Z SUNDAY...BEFORE LIFTING INTO
NORTHERN NEBRASKA BY 00Z MONDAY. IN ASSOCIATION WITH THIS
FEATURE...STRONG TO POSSIBLY SEVERE THUNDERSTORMS WILL BE POSSIBLE
THIS EVENING...FOLLOWED BY THE THREAT FOR HEAVY RAIN
OVERNIGHT...THEN ACCUMULATING SNOWS IN THE EASTERN PANHANDLE AND
NORTHWESTERN SANDHILLS OVERNIGHT. FIRST FOR THE SEVERE THREAT
TONIGHT...A BULGING DRYLINE WILL PUSH FROM SWRN KS INTO NWRN KS BY
06Z SUNDAY. THUNDERSTORMS WILL INITIATE ALONG THIS FEATURE AND
QUICKLY LIFT NORTH INTO SWRN AND SOUTH CENTRAL NEBRASKA. WITH THE
LOW CLOUDS AND COOL CONDS TODAY...THE SEVERE THREAT CONTINUES TO
DIMINISH ACROSS THE SWRN CWA. WITH THIS KIND OF SETUP...DRYLINE TO
THE SOUTH...WARM FRONT TO THE SOUTH...THIS IS TYPICALLY A GOOD SETUP
FOR LARGE HAIL AND THIS WILL BE THE MAIN HAZARD MENTIONED IN THE
HWO. THEN THERE IS THE THREAT FOR SNOW IN THE PANHANDLE AND
NORTHWESTERN SANDHILLS LATER THIS EVENING. ALREADY AS OF 2 PM THIS
AFTERNOON...LIGHT SNOW WAS BEING REPORTED AT CHADRON...WHICH WAS
EARLIER THAN ANTICIPATED WITH THE CURRENT FORECAST. ALREADY HAVE
INCREASED SNOW ACCUMULATIONS IN THE PINE RIDGE AND NERN
PANHANDLE...TO REFLECT AN EARLIER CHANGEOVER OF SNOW. THESE HIGHER
ACCUMS APPG A FOOT WILL BE INCORPORATED IN THE UPDATE OF THE WINTER
STORM WARNING FOR SHERIDAN COUNTY TO BE ISSUED WITH THE AFTERNOON
PACKAGE. SOUTH AND EAST OF SHERIDAN COUNTY...SNOW IS EXPECTED AS
WELL...HOWEVER A MUCH TIGHTER ENVELOPE FOR ACCUMS EXISTS GIVEN
INCREASED MOISTURE AND WARMER TEMPS EXPECTED OVERNIGHT. NO
DOUBT...THE RAIN/SNOW LINE WILL BE VERY TIGHT AND AS IT STANDS RIGHT
NOW...THIS FEATURE RUNS RIGHT THROUGH SHERIDAN COUNTY. TURNING TO
THE HEAVY RAIN THREAT TONIGHT...STRONG MOISTURE ADVECTION CONTINUES
FROM THE SOUTHERN PLAINS INTO NEBRASKA PER 300K MOISTURE TRANSPORT
VECTORS. PW/S WILL INCREASE BY MID EVENING TO 1.1 INCHES AT NORTH
PLATTE...WHICH IS NEAR RECORD FOR THIS TIME OF YEAR. THIS MOISTURE
WILL SHIFT QUICKLY NORTH OVERNIGHT AS THE UPPER LEVEL LOW PUSHES
INTO NORTHEASTERN COLORADO...HOWEVER PW/S WILL STILL BE A HALF TO
2/3RDS OF AN INCH EVEN BEHIND THE DEEPEST AREA OF MOISTURE WHICH
SHIFTS INTO EASTERN NEBRASKA AND SERN SOUTH DAKOTA BY SUNDAY
MORNING. WIDESPREAD PRECIPITATION IS EXPECTED OVERNIGHT...WITH THE
MOST PERSISTENT AREAS TRANSITIONING FROM THE PANHANDLE INTO SWRN AND
CENTRAL NEBRASKA BY LATE EVENING. THIS IS IN RESPONSE TO EXPECTED
CONVECTIVE DEVELOPMENT OVER NORTHWESTERN KS. THE LATEST HRRR AND THE
NAM SOLN FROM THIS MORNING TO A LESSER DEGREE...FOLLOW THIS TREND OF
HEAVIER RAIN SHIFTING INTO SWRN AND CENTRAL NEBRASKA LATER THIS
EVENING...WITH DECREASED QPF IN THE WEST. THIS LULL WILL BE
TEMPORARY HOWEVER. LOOK FOR PCPN TO INCREASE SUNDAY MORNING IN THE
WEST AS DEFORMATION PCPN DEVELOPS ON THE BACK SIDE OF THE EXITING
LOW. THE LATEST 3 HR FLASH FLOOD GUIDANCE IS LESS THAN 1.5 INCHES IN
THE SERN PANHANDLE...KEITH AND PERKINS COUNTIES. THIS AREA HAS
LARGELY ESCAPED THE HEAVY RAIN EARLIER THIS MORNING AND THIS
AFTERNOON. WITH THE HRRR INDICATING HEAVIER RAIN EAST OF THESE
AREAS...WILL FORGO ISSUANCE OF A FLASH FLOOD WATCH FOR THESE AREAS.
FURTHER EAST...3 HR FFG IS AROUND 2 INCHES FOR CUSTER COUNTY SOUTH
OF THE SANDHILLS. AGAIN HRRR QPF/S ARE AROUND 1 TO 2 INCHES IN
CUSTER COUNTY TONIGHT...WHICH IS BELOW FFG SO WILL FORGO A FLASH
FLOOD WATCH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
MODELS VARY SOME WITH AMOUNT OF COLD AIR MOVING THROUGH NORTHERN
NEBRASKA SUNDAY NIGHT AND HAVE GONE WITH COLDER SOLUTION OF THE
NAM. DEFORMATION ZONE WILL CONTINUE TO LIFT THROUGH THE NORTHERN
NEBRASKA SANDHILLS WITH A MIX OF RAIN...RAIN SNOW MIX AND SNOW.
HAVE A COUPLE OF INCHES OF ACCUMULATION WITH THE LIFT ASSOCIATED
WITH THE DEFORMATION ZONE...OVER A VERY SMALL PORTION OF NORTHERN
CHERRY COUNTY. WINDS WILL STAY UP THROUGH MONDAY WITH PRECIP
ENDING THROUGH THE MORNING. LOW TEMPERATURES IN THE 20S NORTHWEST
TO THE MID 30S NORTH CENTRAL...ONEILL. HIGHS IN THE 40S WEST AND
THE 50S SOUTHWEST AND EAST. CLEARING SKIES THROUGH THE DAY WITH
MOSTLY CLEAR SKIES OVER NIGHT. WINDS FALLING OFF AND BECOMING
SOUTH OVER NIGHT WILL ALLOW TEMPERATURES TO FALL TO AROUND
FREEZING. HAVE HELD OFF ON HIGHLIGHTS FOR NOW WITH CURRENT
HIGHLIGHTS OUT. TEMPERATURES REBOUND MONDAY AND TUESDAY AS RIDGE
EXPANDS WEST. WEAK WAVE TO MOVE THROUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING SLIGHT CHANCES RETAINED FOR SOUTHWEST INTO NORTH
CENTRAL NEBRASKA. CHANCES FOR PRECIPITATION RETURN TO THE FORECAST
THURSDAY AND CONTINUE THROUGH THE END OF THE PERIOD AS ENERGY
EJECTS FROM A CLOSED LOW OFF THE PACIFIC COAST AND TEMPERATURES
RISING INTO THE 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1118 PM CDT SAT MAY 9 2015
A POWERFUL UPPER LEVEL STORM SYSTEM WILL TRACK ACROSS EASTERN
COLORADO INTO WESTERN NEBRASKA OVERNIGHT TONIGHT INTO SUNDAY.
WIDESPREAD RAIN AND MVFR TO IFR CIGS ARE EXPECTED AT THE KLBF AND
KVTN TERMINALS THROUGH 00Z MONDAY. RAIN MAY MIX WITH SNOW AT THE
KVTN TERMINAL WITH VISBYS AS LOW AS 2SM OVERNIGHT. FLT CONDS WILL
IMPROVE SUNDAY EVENING WITH CIGS INCREASING TO 5000 FT AGL AT THE
KLBF TERMINAL...AND 1500 FT AGL AT THE KVTN TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SAT MAY 9 2015
THE ONGOING LARGE SCALE AND LONG DURATION HEAVY PRECIP EVENT OVER
THE HIGH PLAINS WILL LEAD TO FLOODING CONCERNS NEXT WEEK ON THE
SOUTH PLATTE RIVER IN SOUTHWEST NEBRASKA INCLUDING
DEUEL...KEITH...AND LINCOLN COUNTIES. AS OF SATURDAY MORNING THE
SOUTH PLATTE RIVER IS ALREADY EXPERIENCING ABOVE NORMAL FLOWS DUE TO
SNOW MELT RUNOFF IN THE FRONT RANGE MOUNTAINS OF COLORADO. LATEST
RIVER FORECAST PROJECTIONS SHOW AN INCREASING THREAT FOR SIGNIFICANT
FLOODING BY THE SECOND HALF OF NEXT WEEK. HOWEVER...HIGH UNCERTAINTY
STILL REMAINS IN THE AMOUNT OF OBSERVED/FORECAST RAINFALL IN
NORTHEAST COLORADO AND WESTERN NEBRASKA...AS WELL AS HOW IT WILL
IMPACT UPSTREAM FLOWS ON THE SOUTH PLATTE RIVER. RIVER FORECASTS
WILL BE CLOSELY MONITORED AND UPDATED AS MORE INFORMATION BECOMES
AVAILABLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM MDT SUNDAY FOR NEZ022-023-056-
094.
WINTER STORM WARNING UNTIL 6 PM MDT SUNDAY FOR NEZ004.
&&
$$
SHORT TERM...CLB
LONG TERM...POWER
AVIATION...CLB
HYDROLOGY...MARTIN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1256 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1245 AM CDT SUN MAY 10 2015
THE DEVELOPING SPRING STORM REMAINS THE FOCUS THIS MORNING.
RECENT RADAR/SATELLITE IMAGERY AND SURFACE OBSERVATION VALIDATION
INDICATE THAT PRECIPITATION REMAINS UNFROZEN AND GENERALLY
SOUTHEAST OF A LINE FROM AMIDON TO CARRINGTON. UPDATES TO THE QPF
AND SNOW AMOUNTS WERE BASED ON THIS INFORMATION...ALONG WITH WPC
QPF A LITTLE FURTHER SOUTH THROUGH 12 UTC THIS MORNING. WHILE THIS
DOES NOT GREATLY REDUCE SNOWFALL FORECASTS...IT DOES PUSH BACK THE
START OF SNOW ACCUMULATION A FEW HOURS.
UPDATE ISSUED AT 926 PM CDT SAT MAY 9 2015
JUST GETTING A LOOK AT LATEST NAM IN THROUGH 36 HOURS. NOT SEEING
SNOW YET WHERE NAM H850 TEMPS ARE MARGINALLY CLOSE TO SNOW TYPE
ACROSS NORTHWEST SD AND SOUTHWEST ND. LOWER BOUNDARY LAYER TEMPS
STILL TOO WARM AS OF YET. DO THINK THERE WILL BE A CHANGE OVER TO
SNOW AFTER MIDNIGHT SOUTHWEST WHERE H850 TEMP IS CLOSE TO -3 C ON
NAM. STILL A LOT OF UNCERTAINTY OUTSIDE OF THE SOUTHWEST. WILL LET
THE WINTER STORM WATCH BEGIN AT 06Z AS PLANNED NORTH OF WARNING
AREA AND AFTER 12Z NORTH AND EAST OF MISSOURI RIVER.
UPDATE ISSUED AT 701 PM CDT SAT MAY 9 2015
THIS UPDATE WILL MAINLY CONCERN CLOUDS AND WINDS AS PRECIP JUST
MOVING INTO THE REGION AT THIS TIME. WITH A NORTHEAST WIND SOME
EVAPORATION OCCURRING BELOW CLOUD BASE WHICH WILL EVENTUALLY
SATURATE THE LAYERS TONIGHT. UPDATED CURRENT TEMPS...WINDS...AND
CLOUDS. WILL WAIT FOR A NEW RUNS LATER THIS EVENING OF SOME SHORT
RANGE MODELS HRRR FOR FURTHER REFINEMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
IMPENDING WINTER STORM DOMINATES THE FORECAST HIGHLIGHTS IN THE
SHORT TERM PERIOD. 12Z MODELS IN DECENT AGREEMENT WITH MAIN
FEATURES.
CURRENTLY...DEEP LOW PRESSURE SWINGING EAST ACROSS THE CENTRAL
ROCKIES...WHICH WILL LIFT NORTHEAST INTO THE HIGH PLAINS TONIGHT.
SFC RIDGE OF HIGH PRESSURE STRETCHING FROM LAKE WINNIPEG SOUTHWEST
THROUGH NORTHEASTERN NORTH DAKOTA INTO SOUTHWESTERN ND. EMBEDDED
S/WV IMPULSES CONTINUE TO LIFT NORTH OUT OF THE UPPER LOW ACROSS
THE DAKOTAS...TRIGGERING PRECIPITATION MAINLY ON THE SOUTHERN EDGE
AND ALONG TO EAST OF THE SFC RIDGE AXIS. CLEAR TO PARTLY CLOUDY
ACROSS MY NORTH WITH STRONGER SUBSIDENCE NEAR THE SFC RIDGE.
PRECIPITATION MAINLY IN THE FORM OF RAIN WILL CONTINUE TO DEVELOP
ACROSS MY FAR SOUTH AND SOUTHEASTERN QUARTER NOW INTO THIS
EVENING WHILE DRIER CONDITIONS LINGER WEST AND NORTH. SFC RIDGE
WASHES OUT/LIFTS NORTH THIS EVENING INTO THE OVERNIGHT WITH A SFC
TROUGH DEVELOPING ACROSS EASTERN SOUTH DAKOTA INTO THE JAMES RIVER
BASIN. PRECIPITATION BAND DEVELOPS IN EARNEST ACROSS SOUTH DAKOTA
OVERNIGHT...LIFTING NORTH ACROSS SOUTHWEST AND CENTRAL NORTH
DAKOTA LATE TONIGHT INTO SUNDAY AS THE UPPER LOW LUMBERS NORTH
INTO SOUTH DAKOTA. INHERITED POP GRIDS LOOKED GOOD SO ONLY SOME
MINOR TWEAKS WERE MADE.
SIGNIFICANT SNOWFALL LIKELY WHERE CURRENT WINTER STORM WARNINGS
ARE IN EFFECT. THERMAL PROFILES ARE MORE SUPPORTIVE OF ALL SNOW OR
MAINLY SNOW WEST OF THE MISSOURI RIVER AND ALONG AND SOUTH OF
INTERSTATE 94 WHERE THERE IS VERY NICE MODEL AGREEMENT ON COOLING
925/850MB TEMPS DUE IN PART TO DYNAMIC COOLING AND ALSO MID LEVEL
CAA. STILL LINGERING UNCERTAINTY NORTH AND EAST OF THIS AREA WHERE
TEMPS ALOFT ARE SLIGHTLY WARMER AND THE BIG QUESTION IS EVENTUAL
SFC TEMPERATURES TONIGHT INTO SUNDAY. 2-3 DEGREES WILL HAVE
SIGNIFICANT IMPACTS TO PRECIP TYPE FOR THIS AREA...AND THUS SNOW
ACCUMULATIONS. FOR EXAMPLE...I RAN TWO SCENARIOS FOR BISMARCK ON
TONIGHT THROUGH SUNDAY. THE FIRST WAS A MORE AVERAGE SOLUTION FOR
TEMPERATURES WHERE I GOT 1-3 INCHES OF WET SNOW THROUGH SUNDAY
AFTERNOON (THIS WAS UTILIZED FOR THIS FORECAST PACKAGE). THE
SECOND SCENARIO WAS 2 DEGREES COOLER...WHICH RESULTED IN 6-9
INCHES (THIS WAS NOT USED). OPTED TO UPGRADE MORTON COUNTY TO A
WINTER STORM WARNING BASED ON FORECAST TEMPS ALOFT (AS DISCUSSED
ABOVE). WILL KEEP THE REMAINDER OF THE WATCH AS IS THROUGH SUNDAY
DUE TO THE LINGERING UNCERTAINTY (SEE LONG TERM BELOW FOR WATCH
EXTENSION DISCUSSION).
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
A STRONG SPRING STORM WILL LINGER THROUGH MONDAY EVENING. THIS
WILL BE THE MAIN FOCUS FOR THE LONG TERM FORECAST.
THE 12 UTC MODELS ARE IN FAIRLY GOOD AGREEMENT WITH RESPECT TO
TIMING AND LOCATION OF THE HEAVIEST PRECIPITATION AND EVOLUTION OF
THE STORM SUNDAY INTO MONDAY. THE 12 UTC GEM AND NAM APPEAR TO BE
ON THE FRINGES WITH THE FORMER LIKELY TOO WET AND TOO FAR TO THE
WEST AND THE LATER TO DRY AND TOO FAR TO THE EAST. FOR THIS
FORECAST UTILIZED A BLEND OF THE GFS/ECMWF/SREF.
THE WINTER STORM WATCH HAS BEEN EXPANDED A LITTLE FURTHER TO THE
EAST AS THERE IS AN INCREASED POTENTIAL FOR ACCUMULATING SNOW
ACROSS PORTIONS OF THE JAMES RIVER VALLEY.
SUNDAY EVENING AND OVERNIGHT...MODERATE TO HEAVY PRECIPITATION IS
EXPECTED TO SPREAD EAST OF THE MISSOURI RIVER AND ALONG I-94 AS A
DEEP SURFACE LOW PROPAGATES ACROSS THE EASTERN DAKOTAS. A
TROWAL...COUPLED WITH STRONG FRONTOGENETIC FORCING WILL LIKELY
PRODUCE HEAVY BANDS OF RAIN/SNOW. AS MUCH AS THREE INCHES OF
LIQUID IS POSSIBLE EAST OF THE MISSOURI RIVER AND ALONG/SOUTH OF
I-94. THE 12 UTC RUNS CONTINUE TO INDICATE H85 TEMPERATURES AROUND
-2C TO -3C AND SURFACE TEMPERATURES HOVERING NEAR FREEZING. THIS
IN TURN COULD LEAD TO ACCUMULATIONS OF HEAVY WET SNOW. AS SUCH
ISSUED A WATCH FOR PORTIONS OF THE JAMES RIVER VALLEY.
HOWEVER...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
PRECIPITATION TYPE AS A FEW DEGREES DIFFERENCE IN SURFACE
TEMPERATURE COULD MEAN THE DIFFERENCE BETWEEN NO SNOW AND 6+
INCHES. IN ADDITION TO HEAVY PRECIPITATION...THIS POTENT STORM
WILL ALSO PRODUCE STRONG WINDS. AS THE LOW WRAPS UP ACROSS THE
EASTERN DAKOTAS...THE PRESSURE GRADIENT WILL STEEPEN. WINDS AROUND
35 MPH WILL BE LIKELY SUNDAY AND MONDAY. DUE TO THE TIMING (RATHER
LATE IN THE SEASON FOR SNOW) AND POTENTIAL IMPACTS FELT IT WAS
NECESSARY TO ISSUE A WATCH AND GIVE A HEADS UP...BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO WARRANT A MAJOR ALERT.
PRECIPITATION WILL CONTINUE ACROSS MAINLY CENTRAL AND EASTERN
PORTIONS OF NORTH DAKOTA THROUGH MONDAY. NORTHWEST NORTH DAKOTA
MAY GET LEFT HIGH AND DRY. TEMPERATURES ACROSS THE SOUTH AND EAST
WILL STRUGGLE TO GET OUT OF THE 30S AND 40S OVER THE NEXT SEVERAL
DAYS...WHILE THE NORTHWEST MAY REACH THE 50S AND 60S.
THERE WILL BE ADDITIONAL CHANCES FOR RAIN
WEDNESDAY/THURSDAY...WITH A WARM UP EXPECTED LATE WEEK INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1245 AM CDT SUN MAY 10 2015
SIGNIFICANT SPRING SNOW STORM WILL IMPACT SOUTHERN NORTH DAKOTA
BEGINNING TONIGHT. VFR AND MVFR CONDITIONS WILL SLOWLY DETERIORATE
AT KDIK/KBIS/KJMS. CONDITIONS WILL CONTINUE THROUGH SUNDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH THROUGH MONDAY MORNING FOR NDZ020-033-040.
WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ034-
041>045.
WINTER STORM WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY
EVENING FOR NDZ022-023-035>037-046-047.
&&
$$
UPDATE...SCHECK
SHORT TERM...NH
LONG TERM...AJ
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS NORMAN OK
430 AM CDT SUN MAY 10 2015
.DISCUSSION...
YET ANOTHER ROUND OF CONVECTION IS SET TO MOVE INTO PART OF
WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA OVER THE NEXT SEVERAL
HOURS. THE HRRR HAS BEEN FAIRLY CONSISTENT IN MOVING THIS COMPLEX
ACROSS AREAS SOUTH AND EAST OF I-44 THROUGH THE MID TO LATE
MORNING...WITH ADDITIONAL STORMS IN SOUTHEAST OKLAHOMA THIS
AFTERNOON. MOST MEDIUM RANGE MODELS ARE SIMILAR WITH THE
HRRR...BUT CONTINUE CONVECTION OVER SOUTH CENTRAL AND SOUTHEAST
OKLAHOMA INTO THE AFTERNOON/EVENING. AREAS ALONG AND SOUTHEAST OF
SEMINOLE...PAULS VALLEY AND HENRIETTA...TEXAS MAY SEE ANOTHER 2 TO
4 INCHES OF RAIN THROUGH THE AFTERNOON/EVENING WHICH WILL RESULT
IN SIGNIFICANT FLASH FLOODING. THE MAIN HAZARDS WITH THE MORNING
CONVECTION WILL BE LARGE HAIL...AND FLOODING RAINFALL.
DEPENDING ON HOW MUCH CONVECTION LINGERS OVER SOUTHEAST
OKLAHOMA...ADDITIONAL THUNDERSTORMS MAY DEVELOP ACROSS NORTH
CENTRAL...CENTRAL AND SOUTHWEST OKLAHOMA AS A COLD FRONT
APPROACHES...SIMILAR TO THE 06Z NAM. INSTABILITY AND SHEAR WILL
SUPPORT THE RISK OF VERY LARGE HAIL AND DAMAGING WINDS.
A COLD FRONT WILL SWEEP ACROSS ALL OF OKLAHOMA AND WESTERN
NORTH TEXAS BY EARLY MONDAY...WHICH WILL BRING A MUCH NEEDED
BREAK FROM SEVERE STORMS AND FLOODING RAIN. ANOTHER SHORT WAVE
TROUGH IS FORECAST TO LIFT ACROSS THE CENTRAL PLAINS ON
WEDNESDAY...WITH ANOTHER ACTIVE SOUTHWEST FLOW PERIOD FROM FRIDAY
INTO NEXT WEEKEND.
FOR NOW...WILL LEAVE THE FLOOD WATCH THE SAME...BUT SHOULD BE
ABLE TO REMOVE NORTHWEST PARTS OF THE WATCH LATER THIS AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 76 51 70 50 / 60 40 0 0
HOBART OK 78 49 70 48 / 20 10 0 0
WICHITA FALLS TX 78 55 72 51 / 70 20 10 0
GAGE OK 74 43 68 43 / 0 10 0 0
PONCA CITY OK 77 48 69 45 / 50 40 0 0
DURANT OK 76 60 75 54 / 90 80 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH MONDAY MORNING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH MONDAY MORNING FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
306 AM EDT SUN MAY 10 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
CONUS THROUGH MONDAY. SUMMER LIKE WEATHER WILL BE ENJOYED BY
MOST...EXCEPT FOR A MOIST MARITIME FLOW BRINGING PERIODS OF LOW
CLOUDS AND FOG TO PORTIONS OF THE LOWER TO MIDDLE SUSQUEHANNA
RIVER VALLEY THROUGH SUNDAY. A SHARP COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM
BUILDING SOUTHEAST INTO PA THE LATER HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
SCT RING OF FIRE CONVECTION CONTINUES TO FIRE WITHIN PLUME OF
ANOMALOUS PWATS ON NW PERIPHERY OF UPPER RIDGE FROM THE MISS
VALLEY INTO NW PA. EXPECT SHOWERS TO DWINDLE OVR WARREN CO EARLY
THIS MORNING...AS BLYR COOLS/STABILIZES. LATEST HRRR SUPPORTS THIS
IDEA WITH SHOWERS TAPERING OFF BTWN 06Z-09Z.
ACROSS THE SE HALF OF THE STATE...FOCUS WILL BE ON MARINE STRATUS
ADVECTING WESTWARD INTO THE AREA TOWARD DAWN. LATEST SREF AND HRRR
OUTPUT SUPPORT THE STRATUS REACHING TO ABOUT THE SUSQ RIVER.
UNCERTAIN IF STRATUS WILL REACH FURTHER WEST INTO THE
RIDGE/VALLEY REGION...BUT IF IT DOESN/T PATCHY RADIATION FOG
APPEARS LIKELY FROM KAOO THRU KUNV AND KIPT. HAVE REMOVED MENTION
OF DZ ACROSS THE EASTERN COUNTIES...WHERE MDL SOUNDINGS INDICATE
DEPTH OF MOISTURE WILL REMAIN TOO SHALLOW TO SUPPORT ANY PRECIP.
TEMPS ON TRACK TO BOTTOM OUT THIS MORNING IN THE L60S MOST SPOTS.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/...
AM LOW CLOUDS/FOG SHOULD ONCE AGAIN MIX OUT BY LATE AM...WITH
AREAS EAST OF KMDT SEEING THE MOST PERSISTENT CLOUD COVER. ENS
MEAN 8H TEMPS SUPPORTIVE OF MAX TEMPS IN THE LOW TO MID 80S.
WARM MID LVL TEMPS ARE LIKELY TO ONCE AGAIN SUPPRESS CONVECTION
OVER MOST OF CENTRAL/SOUTHERN PA. HOWEVER...GEFS/SREF OUTPUT
SUPPORTS A DECENT CHANCE OF PM TSRA ACROSS THE NW MTNS ON NORTHERN
PERIPHERY OF UPPER RIDGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
DID NOT CHANGE MUCH FOR SUNDAY NIGHT INTO TUE. HARD TO SEE MUCH
GOING ON BEFORE MONDAY NIGHT...WHEN THE COLD FRONT MOVES INTO THE
AREA. DID UP TEMPS A LITTLE HERE AND THERE. DID CUT BACK ON POPS
SOME.
WEAK UPPER LEVEL SYSTEM LIFTING NE SUNDAY NIGHT COULD TOUCH OFF
A SHOWER OR STORM.
LACK OF SFC COVERGENCE...HEIGHT FALLS...AND TIMING OF THE COLD
FRONT FOR TUE...HARD TO SEE A LOT OF WIDESPREAD SEVERE STORMS.
STILL HAVE TO WATCH ANY MOISTURE WORKING INTO SE PA FROM
TS ANA.
RATHER STRONG MID LEVEL WIND FIELDS FOR WED. IT WILL BE BREEZY
AND COOL...WITH SOME CLDS AND PERHAPS A SHOWER TO THE NORTH.
MORE DETAIL BELOW.
THE FLOW ALOFT WILL TRANSITION TO A TROUGHING PATTERN BY WED.
CHILLY TEMPS ALOFT WILL LIKELY LEAD TO PLENTY OF STRATOCU/CU
ACROSS THE AREA WED...WITH A SHRA EVEN POSSIBLE ACROSS THE N MTNS
W/PASSAGE OF UPPER TROF AXIS. LOOK FOR TEMPERATURES TO DROP TO
NEAR/BELOW NORMAL WED-THU WITH A COUPLE OF VERY CHILLY MORNINGS
THU/FRI...AS SFC HIGH BUILDS OVR THE AREA. MAY HAVE TO CONTEND
W/POSSIBLE FROST OVR THE NW MTNS THOSE MORNINGS WITH MINS LKLY IN
THE 30S. GROWING SEASON STARTS MAY 11 OVER PARTS OF THE ALLEGHENY
MTNS. CONFIDENCE IN NEAR-FREEZING TEMPS IS HIGHEST IN
MCKEAN/POTTER AND ELK BUT THE GROWING SEASON DOES NOT BEGIN IN
THESE COUNTIES UNTIL MAY 21.
WENT WITH A DRY FCST FOR THU INTO SAT...AS THE UPPER LVL RIDGE
STARTS TO BUILD ACROSS THE EAST AGAIN.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
EARLY THIS OVERNIGHT IN THE NW MTNS...A CLUSTER OF SHOWERS/TSTMS
WILL SLIP BETWEEN KERI-KBFD...IMPACTING KJHW BUT MISSING KBFD. BY
09Z...THIS AREA OF SHOWERS WILL BE QUICKLY DIMINISHING.
MARINE STRATUS/FOG WILL AGAIN WORK IN FROM THE SE. IFR CONDITIONS
HAVE ALREADY REACHED KLNS...AND WILL CONTINUE TO EDGE FURTHER
NORTH/WEST TOWARD THE CENTRAL MTNS MAINLY AFTER 08Z. OVERALL
EXTEND WILL LIKELY BE LARGER THAN LAST NIGHT...POSSIBLY ALL THE
WAY TO KAOO-KUNV-KIPT. THESE REDUCTIONS WILL CLEAR BY MID/LATE
MORNING WITH KMDT-KLNS HOLDING ON TO RESTRICTIONS THE LONGEST.
UPPER RIDGE REMAINS OVER THE REGION SUNDAY. WITH LOW LEVEL
MOISTURE INCREASING...POSS OF CONVECTION WILL BE A BIT HIGHER THAN
SAT. BEST CHANCES WILL BE IN THE NW MTNS...WITH LOW PROBS IN THE
LAURELS AND SE. OVERALL PROBS TOO LOW TO MENTION IN TAFS OUTSIDE
OF KBFD.
OUTLOOK...
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...FITZGERALD/GARTNER/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
156 AM EDT SUN MAY 10 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
CONUS THROUGH MONDAY. SUMMER LIKE WEATHER WILL BE ENJOYED BY
MOST...EXCEPT FOR A MOIST MARITIME FLOW BRINGING PERIODS OF LOW
CLOUDS AND FOG TO PORTIONS OF THE LOWER TO MIDDLE SUSQUEHANNA
RIVER VALLEY THROUGH SUNDAY. A SHARP COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM
BUILDING SOUTHEAST INTO PA THE LATER HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
SCT RING OF FIRE CONVECTION CONTINUES TO FIRE WITHIN PLUME OF
ANOMALOUS PWATS ON NW PERIPHERY OF UPPER RIDGE FROM THE MISS
VALLEY INTO NW PA. EXPECT SHOWERS TO DWINDLE OVR WARREN CO EARLY
THIS MORNING...AS BLYR COOLS/STABILIZES. LATEST HRRR SUPPORTS THIS
IDEA WITH SHOWERS TAPERING OFF BTWN 06Z-09Z.
ACROSS THE SE HALF OF THE STATE...FOCUS WILL BE ON MARINE STRATUS
ADVECTING WESTWARD INTO THE AREA TOWARD DAWN. LATEST SREF AND HRRR
OUTPUT SUPPORT THE STRATUS REACHING TO ABOUT THE SUSQ RIVER.
UNCERTAIN IF STRATUS WILL REACH FURTHER WEST INTO THE
RIDGE/VALLEY REGION...BUT IF IT DOESN/T PATCHY RADIATION FOG
APPEARS LIKELY FROM KAOO THRU KUNV AND KIPT. HAVE REMOVED MENTION
OF DZ ACROSS THE EASTERN COUNTIES...WHERE MDL SOUNDINGS INDICATE
DEPTH OF MOISTURE WILL REMAIN TOO SHALLOW TO SUPPORT ANY PRECIP.
TEMPS ON TRACK TO BOTTOM OUT THIS MORNING IN THE L60S MOST SPOTS.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/...
AM LOW CLOUDS/FOG SHOULD ONCE AGAIN MIX OUT BY LATE AM...WITH
AREAS EAST OF KMDT SEEING THE MOST PERSISTENT CLOUD COVER. ENS
MEAN 8H TEMPS SUPPORTIVE OF MAX TEMPS IN THE LOW TO MID 80S.
WARM MID LVL TEMPS ARE LIKELY TO ONCE AGAIN SUPPRESS CONVECTION
OVER MOST OF CENTRAL/SOUTHERN PA. HOWEVER...GEFS/SREF OUTPUT
SUPPORTS A DECENT CHANCE OF PM TSRA ACROSS THE NW MTNS ON NORTHERN
PERIPHERY OF UPPER RIDGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
RESENT TO ADD SATURDAY TO HEADER ON LINE ABOVE.
DID NOT CHANGE MUCH FOR SUNDAY NIGHT INTO TUE. HARD TO SEE
MUCH GOING ON BEFORE MONDAY NIGHT...WHEN THE COLD FRONT MOVES
INTO THE AREA. DID UP TEMPS A LITTLE HERE AND THERE. DID CUT BACK
ON POPS SOME.
WEAK UPPER LEVEL SYSTEM LIFTING NE SUNDAY NIGHT COULD TOUCH OFF
A SHOWER OR STORM.
LACK OF SFC COVERGENCE...HEIGHT FALLS...AND TIMING OF THE COLD
FRONT FOR TUE...HARD TO SEE A LOT OF WIDESPREAD SEVERE STORMS.
STILL HAVE TO WATCH ANY MOISTURE WORKING INTO SE PA FROM
TS ANA.
RATHER STRONG MID LEVEL WIND FIELDS FOR WED. IT WILL BE BREEZY
AND COOL...WITH SOME CLDS AND PERHAPS A SHOWER TO THE NORTH.
MORE DETAIL BELOW.
THE FLOW ALOFT WILL TRANSITION TO A TROUGHING PATTERN BY WED.
CHILLY TEMPS ALOFT WILL LIKELY LEAD TO PLENTY OF STRATOCU/CU
ACROSS THE AREA WED...WITH A SHRA EVEN POSSIBLE ACROSS THE N MTNS
W/PASSAGE OF UPPER TROF AXIS. LOOK FOR TEMPERATURES TO DROP TO
NEAR/BELOW NORMAL WED-THU WITH A COUPLE OF VERY CHILLY MORNINGS
THU/FRI...AS SFC HIGH BUILDS OVR THE AREA. MAY HAVE TO CONTEND
W/POSSIBLE FROST OVR THE NW MTNS THOSE MORNINGS WITH MINS LKLY IN
THE 30S. GROWING SEASON STARTS MAY 11 OVER PARTS OF THE ALLEGHENY
MTNS. CONFIDENCE IN NEAR-FREEZING TEMPS IS HIGHEST IN
MCKEAN/POTTER AND ELK BUT THE GROWING SEASON DOES NOT BEGIN IN
THESE COUNTIES UNTIL MAY 21.
WENT WITH A DRY FCST FOR THU INTO SAT...AS THE UPPER LVL RIDGE
STARTS TO BUILD ACROSS THE EAST AGAIN.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST HALF OF TONIGHT.
STREAMING MOISTURE ALONG A BOUNDARY IS SLOWLY PROGRESSING INTO
THE NW MTNS. THIS WILL BRING SHOWERS AND POSSIBLE MVFR CIGS AND
FOR A SHORT TIME...IFR IS POSSIBLE...TO BFD. TONIGHT WE LIKELY SEE
A REPEAT PERFORMANCE OF THE MARINE STRATUS/FOG WORKING INTO THE SE
COUNTIES - MAINLY AFTER 08Z. LATEST MDL SOUNDINGS/SREF OUTPUT
SUGGESTS THE THREAT OF LOW CLOUDS/FOG WILL EXTEND FURTHER NW THAN
THIS AM...POSSIBLY ALL THE WAY TO KAOO- KUNV-KIPT. HAVE INCLUDED
UNV...BUT HELD OFF ON IPT AND AOO THOUGH MVFR CIGS REMAIN
POSSIBLE. ALL REDUCING CIGS AND VSBYS WILL CLEAR BY LATE MORNING
WITH MDT AND LNS BEING HOLDING ONTO RESTRICTIONS THE LONGEST.
OUTLOOK...
SUN...AM LOW CLOUDS/FOG POSSIBLE MAINLY SE. ISOLD PM TSRA IMPACTS
POSS W MTNS.
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...FITZGERALD/GARTNER/MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
412 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE
LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO
OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC
LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO
CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST
LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO
THE AREA BY MID TO LATE MORNING.
MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED
SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE
AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW
MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE
MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT
SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z.
TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL
INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG
RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK
SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING
VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE
RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE
LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z
WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER
AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND
EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS
THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND
DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE
RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1
EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED
TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z.
SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST
THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL
BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY
QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL
BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE
UPPER 30S TO MID 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY
ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND
COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY
STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS
THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER
ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL
ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD
REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE
MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY
SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S.
LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY
BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY
WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE
MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH
SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS
THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE
MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE
WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER
CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE
STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS
HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN
TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING
GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE
70S BY LATE IN THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1016 PM CDT SAT MAY 9 2015
CONDITIONS WILL GRADUALLY DIMINISH OVERNIGHT AS A STRONG LOW
PRESSURE SHIFTS NORTHWARD. SHOWERS WILL INCREASE IN COVERAGE FROM
THE SOUTH AND SOUTHWEST AND A FEW THUNDERSTORMS WILL ALSO BE
POSSIBLE FROM ABOUT 9Z THROUGH 14Z. OTHERWISE CEILINGS WILL LOWER
TO MVFR AND POSSIBLY IFR AT TIMES AS THE STRONG LOW LEVEL JET AND
MOISTURE ALOFT INCREASE. WHILE THERE IS LIKELY TO BE A BIT OF A
LULL IN ACTIVITY FROM LATE MORNING INTO THE EARLY AFTERNOON STRONG
TO SEVERE THUNDERSTORMS WILL BECOME POSSIBLE OVER FAR SOUTHEAST
SOUTH DAKOTA, NORTHEAST NEBRASKA AND NORTHWEST IOWA AFTER ABOUT
21Z. MVFR CEILINGS WILL BE POSSIBLE THROUGH MUCH OF THE PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...JH
AVIATION...08
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
416 AM CDT SUN MAY 10 2015
.DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...
06Z TAFS
WEAK UPPER DISTURBANCE WAS MOVING EAST THROUGH AR AT 0445Z. THIS
FEATURE WILL LIKELY HELP SUSTAIN SHRA/ISOLATED TSRA INTO THE
MIDSOUTH OVERNIGHT. TS POTENTIAL WILL LIKELY BE BEST IN THE JBR
AREA.
MUCH OF SUNDAY SHOULD SEE VFR. SLIGHT RIDGING SHOULD KEEP
MENTIONABLE TS CHANCES AT BAY UNTIL AFTERNOON...OR MORE LIKELY...
EARLY SUNDAY EVENING AT JBR.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY
AFTERNOON FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-
LAWRENCE-LEE AR-MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST.
FRANCIS.
MO...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY
AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1145 PM CDT SAT MAY 9 2015
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 806 PM CDT SAT MAY 9 2015/
UPDATE...
MAIN UPDATE TO THE FORECAST WAS TO INCREASE PRECIP CHANCES ACROSS
WESTERN PORTIONS OF THE CWA WHERE A COMPLEX OF SHOWERS AND
THUNDERSTORMS WAS ONGOING. WHILE LARGE SCALE FORCING REMAINS
WEAK...CONTINUED CONVERGENCE DRIVEN BY SOUTHEASTERLY FLOW AHEAD
THE SYSTEM WILL AT LEAST MAINTAIN THIS COMPLEX FOR THE NEXT 1-2
HOURS...IF NOT LONGER. TEMPERATURES ACROSS THIS AREA WERE COOLER
THAN FORECAST AS WELL...THEREFORE...ADJUSTED TRENDS TO REFLECT
THIS THROUGH MIDNIGHT.
A VERY COMPLEX SURFACE PATTERN WILL CONTINUE THROUGH TOMORROW WITH SEVERAL
OUTFLOW BOUNDARIES LIKELY STREWN ACROSS THE CWA. PRECIP CHANCES
MAY NEED TO BE ADJUSTED ONCE MORE LATER THIS EVENING AS TRENDS
EVOLVE THROUGH THE NIGHT.
TVT
PREV DISCUSSION... /ISSUED 650 PM CDT SAT MAY 9 2015/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 320 PM CDT SAT MAY 9 2015/
DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON PLACES A QUASI-
STATIONARY BOUNDARY OVER PORTIONS OF SOUTHERN MISSOURI AND BACK
INTO OKLAHOMA AND PORTIONS OF THE TEXAS/OKLAHOMA PANHANDLE.
SHOWERS AND THUNDERSTORM COVERAGE HAS DECREASED IN COVERAGE ACROSS
THE MID SOUTH THIS AFTERNOON AS THE ATMOSPHERE HAS STABILIZED
SOMEWHAT. A CLUSTER OF SHOWERS ARE LOCATED ACROSS PORTIONS OF
NORTH CENTRAL AND NORTHEAST ARKANSAS AS OF LATE THIS AFTERNOON.
TEMPERATURES AS OF 3 PM CDT ARE IN THE UPPER 70S TO LOWER 80S AT
MOST LOCATIONS.
WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES OVER THE PAST FEW
HOURS HAVE INDICATED ANOTHER MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS
DEVELOPED ACROSS OKLAHOMA AND THE RED RIVER VALLEY OF TEXAS.
WRF/GFS/ECMWF MODELS INDICATE THIS ACTIVITY SHOULD REMAIN MAINLY
WEST OF THE FORECAST AREA THIS EVENING. INTERESTINGLY ENOUGH...THE
19Z HRRR INDICATES CONVECTIVE ACTIVITY OVER NORTHEAST
TEXAS/EASTERN OKLAHOMA...AND SOUTHWEST ARKANSAS MAY SPREAD INTO
PORTIONS OF THE MID SOUTH ALONG AND WEST OF THE RIVER BY EARLY TO
MIDDLE EVENING. THIS HIGH RESOLUTION MODEL/S OUTPUT MAY BE TRYING
TO SUGGEST A COLD POOL DEVELOPING UPSTREAM AND BRINGING THE
CONVECTION INTO THE FORECAST AREA. WILL GO WITH CHANCE POPS ALONG
AND WEST OF THE MISSISSIPPI RIVER TONIGHT. EVENING SHIFT WILL
MONITOR MESOSCALE TRENDS AND ADJUST FORECAST AS NECESSARY
ESPECIALLY IF THE OUTLYING HRRR ENDS UP BEING THE CORRECT SHORT
TERM FORECAST SOLUTION.
SHORT TERM MODELS INDICATE SOUTHWEST FLOW ALOFT WILL REMAIN IN
PLACE ACROSS THE MID SOUTH ON SUNDAY WITH MOST IF NOT ALL SHOWERS
AND THUNDERSTORMS OCCURING UPSTREAM OF THE MID SOUTH.
CONSEQUENTLY...HAVE KEPT POPS ISOLATED AT BEST DURING THE DAY WITH
THE EXCEPTION OF EXTREME NORTHEAST MISSISSIPPI. ADDITIONAL SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND SPREAD INTO THE MID SOUTH
SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS INTO THE MID SOUTH.
THE BEST UPPER LEVEL FORCING AND FAVORABLE WINDS WILL MOVE
NORTHEAST OF THE FORECAST AREA BY MONDAY. SUFFICIENT
INSTABILITY...0-6 KM BULK SHEAR AND THE APPROACHING FRONT MAY BE
ENOUGH TO PRODUCE A CONDITIONAL THREAT FOR A FEW STRONG TO
PERHAPS SEVERE THUNDERSTORMS ACROSS THE MID SOUTH LATE SUNDAY
NIGHT INTO MONDAY.
THIS FRONT IS EXPECTED TO PUSH SOUTH OF THE FORECAST AREA BY
TUESDAY AFTERNOON/TUESDAY NIGHT AND BRING MAINLY RAIN FREE WEATHER
THROUGH WEDNESDAY NIGHT. SHOWER/THUNDERSTORM CHANCES WILL RETURN
LATE NEXT WEEK AS THE FRONT RETURNS BACK NORTH ACROSS THE MID
SOUTH.
CJC
&&
.AVIATION...
06Z TAFS
WEAK UPPER DISTURBANCE WAS MOVING EAST THROUGH AR AT 0445Z. THIS
FEATURE WILL LIKELY HELP SUSTAIN SHRA/ISOLATED TSRA INTO THE
MIDSOUTH OVERNIGHT. TS POTENTIAL WILL LIKELY BE BEST IN THE JBR
AREA.
MUCH OF SUNDAY SHOULD SEE VFR. SLIGHT RIDGING SHOULD KEEP
MENTIONABLE TS CHANCES AT BAY UNTIL AFTERNOON...OR MORE LIKELY...
EARLY SUNDAY EVENING AT JBR.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1138 PM CDT SAT MAY 9 2015
.AVIATION...
VFR AND LIGHT WINDS EXPECTED THRU THE TAF PERIOD WITH THE
EXCEPTION OF THE POSSIBILITY OF SOME LOW CLOUDS AT KCDS THIS
MORNING. KCDS REMAINS ON THE MOIST SIDE OF A SFC TROUGH THAT HAS
BEEN MOSTLY STATIONARY THRU THE EVENING BUT WILL BEGIN TO MOVE EWD
AGAIN TOWARD SUNRISE. SEEING SOME AREAS OF LOW CLOUD NORTH AND NE
OF KCDS ATTM WITH MODELS CONTINUING TO INDICATE A WINDOW FOR IFR
OR MVFR CIGS BTWN 06Z AND 12Z.
&&
.PREV DISCUSSION... /ISSUED 903 PM CDT SAT MAY 9 2015/
UPDATE...
HAVE REMOVED EVENING THUNDER MENTION FOR THE FAR ERN SLIVER OF
THE FCST AREA AS THAT THREAT HAS MOVED EAST OF THE REGION. TEMP
AND HUMIDITY FCST FOR THE ROLLING PLAINS AND FAR SERN PANHANDLE
PROBLEMATIC AS THE DRYLINE DID NOT QUITE GET ENTIRELY EAST OF THE
FCST AREA. CURRENTLY SEEING A BATTLE BETWEEN OUTFLOW-REINFORCED
MOIST AIRMASS MOVING EWD AND THE DRYLINE/SFC TROUGH. THIS TROUGH
SHOULD END UP MOVING TO THE EAST AGAIN AS THE UPPER LOW OVER
COLORADO MOVES ONTO THE PLAINS. HOWEVER UNTIL THEN...DEW POINTS
IN THE 60S WILL KEEP TEMPS THERE MILD UNTIL LATE TONIGHT AND MAY
SEE SOME LOW CLOUDS MOVE INTO THE CHILDRESS AREA AROUND MIDNIGHT
AND LINGER FOR SEVERAL HOURS BEFORE DRIER LOW LEVEL AIR CAN
FINALLY SWEEP THE MOISTURE EWD.
PREV DISCUSSION... /ISSUED 634 PM CDT SAT MAY 9 2015/
AVIATION...
DRYLINE HAS SHIFTED AS FAR EAST AS JUST OUTSIDE KCDS. GUSTY WSW
WINDS BEHIND SHOULD DIMINISH BY MID-EVENING WITH VFR CONDITIONS
EXPECTED AT BOTH KLBB AND KPVW. HOWEVER...EAST OF THE DRYLINE
VCTY KCDS RICH LOW LEVEL MOISTURE REMAINS. WITH A PUSH OF THE
DRYLINE A BIT TO THE WEST TONIGHT WOULD EXPECT MOISTURE TO BE
REINFORCED FROM DOWN THE RED RIVER VALLEY. THUS HAVE SIDED WITH
THE HI-RES HRRR AND INTRODUCED LOW CLOUDS IN THE KCDS TAF FROM
LATE EVENING TO AROUND SUNRISE SUNDAY. MAY VERY WELL END UP BEING
IFR THERE IF THESE CLOUDS DEVELOP...BUT HAVE STARTED JUST ABOVE
THAT CUTOFF ATTM.
PREV DISCUSSION... /ISSUED 534 PM CDT SAT MAY 9 2015/
SHORT TERM...
PACIFIC FRONT/DRYLINE HAS SURGED EAST THIS AFTERNOON AS EXPECTED AS
DRY SLOTTING HAS MOVED IN ALOFT ACROSS THE REGION. CORE OF THE UPPER
LOW CURRENTLY NEAR THE FOUR CORNERS REGION WILL LIFT TOWARD THE
FRONT RANGE INTO THIS EVENING WITH A SURFACE LOW HUGGING THE FRONT
RANGE/CENTRAL HIGH PLAINS. DEWPOINTS HAVE CRASHED INTO THE 20S/30S
ACROSS MUCH OF THE CAPROCK...BUT OUTFLOW BOUNDARIES FROM THIS
MORNING/S CONVECTION COUPLED WITH STOUT MOIST SOUTHEASTERLY FLOW
ACROSS THE BIG COUNTRY HAVE HUNG UP THE DRYLINE ON A LINE FROM LAKE
MACKENZIE TO ROARING SPRINGS TO HASKELL. HAVE LEFT A SLIGHT CHANCE
FOR STORMS IN THE FORECAST ALONG AND EAST OF HIGHWAY 83 AS SURFACE
CONVERGENCE ALONG THIS BOUNDARY MAY BE JUST ENOUGH TO INITIATE
ISOLATED DEVELOPMENT WHEN COUPLED WITH CONTINUED WEAK HEIGHT FALLS
ALOFT. THIS CHANCE WILL BE HIGHLY CONDITIONAL ON WHETHER ENOUGH
HEATING WILL BE ABLE TO OCCUR IN A WORKED OVER/COLD POOL PLAGUED
AIRMASS.
WILL CONTINUE TO SEE A FEW LOBES OF ADDITIONAL ENERGY ROUND THE BASE
OF THE UPPER LOW THROUGH EARLY SUNDAY...BUT DRIER AIR COURTESY OF
DOWNSLOPE SURFACE WINDS WILL KEEP STORMS MAINLY CONFINED EAST OF THE
FAR EASTERN EDGE OF THE ROLLING PLAINS. SUNDAY MORNING LOOKS TO
BRING THE NEXT/LAST APPRECIABLE ROUND OF UPPER ENERGY TOWARD WEST
TEXAS...SO WILL KEEP A MENTION SOUTHEAST OF A GUTHRIE TO ASPERMONT
LINE AS 40 DEGREE DEWPOINTS MAY BE ENOUGH TO SPARK A QUICK STORM.
OTHERWISE...BREEZY WEST/SOUTHWEST WINDS SHOULD ACCOMPANY
TEMPERATURES TOPPING OUT IN THE MID 70S NORTHWEST TO LOW 80S SOUTH
AND EAST UNDER MOSTLY CLEAR SKIES.
LONG TERM...
WE/LL SEE A BREAK IN OUR ACTIVE WEATHER PATTERN THROUGH MONDAY...BUT
THE CHANCE FOR SHOWERS AND T-STORMS WILL INCREASE AGAIN NEXT WEEK.
THE COLD FRONT WILL BE EXITING THE FORECAST AREA MONDAY MORNING WITH
BREEZY NORTHERLY WINDS DIMINISHING AND SWINGING AROUND TO THE E-SE
BY MONDAY EVENING. IT WILL BE ON THE COOL SIDE BEHIND THE FRONT
MONDAY WITH HIGHS MAINLY IN THE UPPER 60S AND LOWER 70S. SHORTWAVE
RIDGING WILL DEVELOP OVER WEST TEXAS TUESDAY DOWNSTREAM OF A UPPER
TROUGH MOVING ACROSS THE WEST COAST. INDICATIONS ARE THAT THIS
TROUGH WILL BE PROGRESSIVE AND MAY BEGIN TO AFFECT THE REGION BY
TUESDAY EVENING. THE NAM IS THE MOST BULLISH OF THE MODELS WITH THE
QPF FORECAST...GENERATING A SWATH OF RAIN COMING IN FORM THE SW TUES
AFTERNOON AND EVENING. THIS MAY BE OVERDONE GIVEN THAT IT WILL TAKE
SOME TIME FOR LOW-LEVEL MOISTURE TO RECHARGE AND THE ECMWF AND GFS
ARE SLOWER WITH THE LIFT. WE WILL MAINTAIN A CHANCE OF PRECIP IN THE
SW SPLNS...TAPERING DOWN FARTHER EAST TUESDAY EVENING AND
OVERNIGHT. THE GFS AND ECMWF STILL INDICATE THAT WED WILL BE THE
PRIMARY PERIOD FOR RAIN CHANCES WITH A WELL-DEVELOPED SHORTWAVE
OUT OF NM AND ACROSS WEST TEXAS...AT ROUGHLY THE SAME TIME DEEP
GULF MOISTURE IS MOVING BACK INTO THE AREA. PROGGED QPF AMOUNTS
ARE QUITE HIGH...WITH A SIMILAR APPEARANCE TO OUR LAST STRONGLY
FORCED CONVECTION MAY 5TH. HOWEVER...THIS IS STILL 5 DAYS OUT AND
WE MAY NOT SEE LIFT AND MOISTURE QUITE AS SYNCHRONIZED THIS TIME.
SHORTWAVE LIFTS NWD AWAY FROM THE AREA ON THURSDAY BUT THE UPPER
TROUGH TO OUR WEST WILL BE QUICK TO RELOAD AS NEXT ROUND OF
ENERGY DROPS INTO THE SW. THE EMCWF AND GFS BEGIN TO DIVERGE BY
THIS TIME AS THE ECMWF DROPS A UPPER LOW ALL THE WAY INTO SRN
CALIFORNIA WHILE THE GFS BREAKS THE ENERGY UP INTO SEVERAL PIECES
MOVING ACROSS THE GREAT BASIN AND 4-CORNERS REGIONS. EITHER WAY
LOW-LEVEL MOISTURE SHOULD BE DRAWN WEST INTO ERN NM AND
PERTURBATIONS IN THE SWRLY FLOW OVER WTX SHOULD BE SUFFICIENT TO
SUPPORT AT LEAST SOME DIURNAL T- STORM DEVELOP EACH AFTN AND
EVENING FRI...SAT AND PERHAPS INTO SUNDAY JUST DEPENDING ON HOW
THE UPPER TROUGH/LOW ACROSS THE WEST EVOLVES.
FIRE WEATHER...
WARM...DRY AND BREEZY CONDITIONS WILL PERSIST THROUGH EARLY EVENING
ACROSS THE CAPROCK. OVERNIGHT MOISTURE RECOVERY WILL BE POOR AS
THE DRYLINE REMAINS TO THE EAST. SIMILAR CONDITIONS ARE EXPECTED
ACROSS THE ENTIRE FORECAST AREA ON SUNDAY. HOWEVER...THE FIRE
WEATHER CONCERNS WILL REMAIN LOW DUE TO THE RECENT WIDESPREAD WETTING
RAINS A GREENUP. A COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY MORNING BRINGING A PERIOD OF GUSTY NORTHERLY WINDS.
SEASONABLE COOL AND DRY CONDITIONS ARE EXPECTED MONDAY...WITH
MOISTURE LEVELS AND RAIN CHANCES ON THE INCREASE BY LATE TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 74 41 69 / 0 0 10 0
TULIA 48 74 44 69 / 0 0 10 0
PLAINVIEW 45 75 45 69 / 0 0 10 0
LEVELLAND 46 77 46 71 / 0 0 10 0
LUBBOCK 46 78 47 71 / 0 0 10 0
DENVER CITY 48 78 47 73 / 0 0 0 0
BROWNFIELD 48 79 48 73 / 0 0 10 0
CHILDRESS 59 81 51 71 / 0 0 10 0
SPUR 54 81 51 71 / 0 0 10 0
ASPERMONT 60 83 54 73 / 10 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT SUN MAY 10 2015
.DISCUSSION...
TODAY...ANA WILL DRIFT NORTH ACROSS THE CAROLINAS...CONTINUING THE
SLOW MIGRATION OF THE LOW LEVEL ATLANTIC RIDGE NORTHWARD. EARLY
MORNING VISIBLE SATELLITE IMAGERY CLEARLY SHOWED CLOUD LINES
DELINEATING THE RIDGE AXIS ACROSS THE NORTHERNMOST BAHAMAS.
MORNING SOUNDINGS AND GPS PRECIPITABLE WATER DATA SHOWED MOISTENING
AT MIAMI BUT DRIER AIR LINGERING FROM TAMPA TO OKEECHOBEE. THE GFS
MOVES THIS DRIER RIBBON NORTHWARD AND INCREASES MOISTURE CONVERGENCE
IN OUR SOUTHERN AREAS...WHILE DECREASING MOISTURE ACROSS THE NORTH.
THEREFORE...EXPECT A SLIGHT CHANCE FOR STORMS ALONG THE INLAND
MOVING SEA BREEZE FROM THE TREASURE COAST TO OKEECHOBEE AND SOUTH
OSCEOLA. THIS FITS THE 12Z HRRR MODEL AND THE TYPICAL PATTERN OF
HIGHER MOISTURE CONVERGENCE ZONE OCCURRING JUST NORTH OF THE RIDGE
AXIS.
ANY SHOWER/STORM CHANCES ACROSS THE NORTH WILL BE LATE AND WELL
INLAND WITH THE EAST/WEST COAST SEA BREEZE COLLISION.
WILL NOT CHANGE THE CURRENT FORECAST THAT DEPICTS LOW THRESHOLD
POPS. TEMPS ALOFT ARE QUITE COOL THOUGH...SO WHERE THE GREATEST
BOUNDARY COLLISIONS OCCUR...STRONG STORMS ARE POSSIBLE.
&&
.AVIATION...MAINLY VFR. ONLY A SLIGHT CHANCE FOR STORMS MAINLY
INLAND BETWEEN KMLB-KSUA AND PROBABLY SOUTH OF KMCO/KISM. LIGHT WIND
REGIME...EXCEPT KMLB-KSUA WHERE THE SEA BREEZE SHOULD BE GUSTY TO
NEAR 20 KNOTS.
&&
.MARINE...
TODAY-TONIGHT...ATLANTIC HIGH PRESSURE RIDGE AXIS WILL CONTINUE TO
MIGRATE SLOWLY NORTHWARD FROM THE NORTHERN BAHAMAS. THIS WILL
PRODUCE A SOUTHERLY WIND FLOW...MAINLY AROUND 10 KNOTS. DIURNAL
INCREASES TO 15 KNOTS WILL OCCUR WITH THE SEA BREEZE NEAR SHORE AND
OFFSHORE OVERNIGHT. SO OVERALL THERE WILL BE A LITTLE MORE WIND
WAVE COMPARED TO THE LAST COUPLE DAYS. SMALL CHANCES FOR SHOWERS AND
STORMS WILL EXIST ON ATLANTIC CLOUD LINES INTO TONIGHT.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1046 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1045 AM CDT SUN MAY 10 2015
WILL UPDATE THE FORECAST LATE THIS MORNING FOR SOME ADJUSTMENT TO
CHANCES OF SHOWERS AND THUNDERSTORMS REST OF THE DAY...AS
CONVECTION AS BEEN MORE WIDELY SCATTERED THIS MORNING. ALSO HAVE
LINGERING FOG OVER NORTHERN COUNTIES NORTH OF WARM FRONT AND
LOCALLY DENSE THIS MORNING. THE WARM FRONT CURRENTLY WAS SLOWLY
LIFTING NORTH AND WAS SOUTH OF MACOMB AND PEORIA AND JUST PASSED
NORTH OF BLOOMINGTON AIRPORT A HALF HOUR AGO. THE FRONT WILL
SLOWLY PUSH NORTH ACROSS NORTHERN COUNTIES THIS AFTERNOON AND THIS
AREA WILL HAVE BEST CHANCES OF DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS IN WARM/HUMID AIRMASS. ANOTHER AREA OF CONVECTION
WILL SPREAD NE ACROSS CENTRAL IL DURING THE EVENING. SPC CONTINUES
SLIGHT RISK OF SEVERE STORMS LATER THIS AFTERNOON AND EVENING
ACROSS MUCH OF CENTRAL IL ESPECIALLY FROM I-57 WEST WHERE CAPES
GET TO 1500-2500 J/KG BY 00Z/7 PM CENTRAL AND WESTERN CWA AND BULK
SHEAR TO 25-35 KTS WESTERN CWA BY SUNSET. HIGHS TO RANGE FROM LOW
TO MID 70S FAR NORTHERN 3 COUNTIES OF KNOX...STARK AND MARSHALL...
TO THE UPPER 70S AND LOWER 80S FROM PEORIA SOUTH.
&&
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF
10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE
SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR
WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE
CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN
CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING
THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER
SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC
SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI.
GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT
RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS
MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE
AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE
CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA
STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON.
BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS
SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF
MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE
AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE
SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT
EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER
GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY
DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL
DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE
CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST
ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS
DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS
THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE
SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND
HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH
TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS
WILL TOP THE 80 DEGREE MARK.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS
EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL
TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING
INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS
THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS
ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE
MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN
PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA
MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING
FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE
AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED
POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON.
ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE
60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL
BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF
ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND
INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL
SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE
SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24
HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE
CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE
GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO
THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 600 AM CDT SUN MAY 10 2015
A WARM FRONT...CURRENTLY LOCATED FROM JUST NORTH OF KSPI AND KCMI
WILL EDGE NORTHWARD TODAY WITH MOSTLY LIFR TO VLIFR CIGS AND VSBYS
TO ITS NORTH...WHILE MVFR AND VFR CIGS WERE PREVALENT TO ITS
SOUTH THIS MORNING. HOW QUICKLY THE CIGS AND VSBYS IMPROVE AS THE
FRONT MOVES NORTH WILL BE THE PRIMARY CONCERN EARLY ON DURING THIS
FORECAST PERIOD...WITH TIMING OF STRONG TO LOCALLY SEVERE STORMS
AFTER 20Z THE NEXT CONCERN DURING THE SECOND HALF OF THE FORECAST
PERIOD. WITH MOST OF THE SHORT TERM MODELS NOT PUSHING THE FRONT
TO THE NORTH OF THE TAF SITES BY EARLY THIS AFTERNOON...WILL BRING
CIGS AND VSBYS UP IN THE AREAS NORTH OF THE FRONT THIS MORNING
WHILE MVFR TO LOW VFR CIGS EXPECTED OVER THE REMAINDER OF THE
TAF SITES THIS AFTERNOON. BASED ON THE LATEST SOUNDING DATA...
IT APPEARS BASES WILL IMPROVE TO SCT-BKN CIGS FROM AROUND 2500-3500
FEET BY EARLY THIS AFTERNOON.
CONVECTION LOOKS TO DEVELOP OVER PARTS OF CENTRAL AND SOUTH
CENTRAL MISSOURI BY THIS AFTERNOON AND PUSH EAST AND NORTHEAST
INTO OUR FORECAST AREA BETWEEN 21Z AND 00Z AND LAST THRU ABOUT
05Z BEFORE TAPERING OFF TO SHOWERS FOR THE REMAINDER OF THE
TIME PERIOD. SURFACE WINDS WILL BE EASTERLY AT 5 TO 12 KTS
NORTH OF THE WARM FRONT FOR THE NEXT SEVERAL HOURS...BUT MOST
AREAS SHOULD SEE SOUTH TO SOUTHEAST WINDS AT 10 TO 15 KTS TODAY
WITH SOUTHEASTERLY FLOW EXPECTED TONIGHT AT 8 TO 15 KTS...WHICH
SHOULD BECOME SOUTH LATE TONIGHT AT 12 TO 17 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
605 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF
10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE
SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR
WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE
CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN
CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING
THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER
SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC
SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI.
GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT
RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS
MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE
AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE
CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA
STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON.
BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS
SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF
MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE
AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE
SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT
EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER
GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY
DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL
DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE
CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST
ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS
DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS
THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE
SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND
HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH
TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS
WILL TOP THE 80 DEGREE MARK.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS
EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL
TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING
INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS
THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS
ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE
MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN
PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA
MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING
FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE
AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED
POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON.
ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE
60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL
BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF
ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND
INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL
SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE
SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24
HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE
CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE
GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO
THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 600 AM CDT SUN MAY 10 2015
A WARM FRONT...CURRENTLY LOCATED FROM JUST NORTH OF KSPI AND KCMI
WILL EDGE NORTHWARD TODAY WITH MOSTLY LIFR TO VLIFR CIGS AND VSBYS
TO ITS NORTH...WHILE MVFR AND VFR CIGS WERE PREVALENT TO ITS
SOUTH THIS MORNING. HOW QUICKLY THE CIGS AND VSBYS IMPROVE AS THE
FRONT MOVES NORTH WILL BE THE PRIMARY CONCERN EARLY ON DURING THIS
FORECAST PERIOD...WITH TIMING OF STRONG TO LOCALLY SEVERE STORMS
AFTER 20Z THE NEXT CONCERN DURING THE SECOND HALF OF THE FORECAST
PERIOD. WITH MOST OF THE SHORT TERM MODELS NOT PUSHING THE FRONT
TO THE NORTH OF THE TAF SITES BY EARLY THIS AFTERNOON...WILL BRING
CIGS AND VSBYS UP IN THE AREAS NORTH OF THE FRONT THIS MORNING
WHILE MVFR TO LOW VFR CIGS EXPECTED OVER THE REMAINDER OF THE
TAF SITES THIS AFTERNOON. BASED ON THE LATEST SOUNDING DATA...
IT APPEARS BASES WILL IMPROVE TO SCT-BKN CIGS FROM AROUND 2500-3500
FEET BY EARLY THIS AFTERNOON.
CONVECTION LOOKS TO DEVELOP OVER PARTS OF CENTRAL AND SOUTH
CENTRAL MISSOURI BY THIS AFTERNOON AND PUSH EAST AND NORTHEAST
INTO OUR FORECAST AREA BETWEEN 21Z AND 00Z AND LAST THRU ABOUT
05Z BEFORE TAPERING OFF TO SHOWERS FOR THE REMAINDER OF THE
TIME PERIOD. SURFACE WINDS WILL BE EASTERLY AT 5 TO 12 KTS
NORTH OF THE WARM FRONT FOR THE NEXT SEVERAL HOURS...BUT MOST
AREAS SHOULD SEE SOUTH TO SOUTHEAST WINDS AT 10 TO 15 KTS TODAY
WITH SOUTHEASTERLY FLOW EXPECTED TONIGHT AT 8 TO 15 KTS...WHICH
SHOULD BECOME SOUTH LATE TONIGHT AT 12 TO 17 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
755 AM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 748 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL FAVOR MVFR CIGS AT SAW UNTIL
WINDS VEER MORE TO THE E WHEN SOME IMPROVEMENT TO VFR IS EXPECTED.
VFR CONDITIONS AT CMX ARE EXPECTED TO GIVE WAY MVFR AS WINDS BECOME
MORE EASTERLY WHICH WILL DRAW IN MORE UPSTREAM LOW LEVEL MOSITURE.
WINDS VEERING TO ENE AT IWD WILL BE LESS FAVORABLE FOR LOWER CIGS.
SO...VFR CONDITIONS SHOULD PERSIST UNTIL AT LEAST LATER IN THE
AFTERNOON. SOME LIGHT RAIN MAY MOVE INTO IWD BY LATE THIS EVENING AND
LATE TONIGHT AT SAW WHICH WILL HELP LOWER CIGS BACK INTO THE MVFR
RANGE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
714 AM CDT Sun May 10 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 355 AM CDT Sun May 10 2015
Warm front just north of the I-70 corridor will continue advancing
slowly northward this morning and should be well north of the
forecast area into Iowa and northern Illinois by 17-18Z. Deep
moisture combined with another passing MCV and low level warm
advection will continue to produce scattered showers and the
occasional thunderstorm this morning. The primary shortwave over
northeast Colorado is finally moving, opening up, and being drawn up
into the mean flow. Should see the surface low associated with the
wave tighten up and move from western Kansas into northeast Nebraska
or northwest Iowa by early evening. Short range guidance suggests
there will be another wave of rain and thunderstorms this afternoon
well ahead of the cold front, probably triggered by another MCV
generated by the convection now occurring over central Texas. NAM
and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm
sector across the area for this MCV to work with. Add in 40+ kts of
0-6km shear and severe thunderstorms look more likely today than the
past couple of days. Not sure what the mode of thunderstorm
development will ultimately be, but would a few discrete rotating
storms will be possible before everything congeals into clusters or
broken lines.
Carney
.LONG TERM: (Tonight through Saturday)
Issued at 355 AM CDT Sun May 10 2015
Southwest flow aloft will persist for much of this period, only
ending when the main TROF ejects thru our region. Thrown into the
mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system currently over the central High Plains. This will yield high
PoPs thru Monday.
Severe storm potential still on track today and tonight, with the
best timeframe from mid-afternoon into mid-evening as better bulk
shear enters the fray during this time and there should still be
enough instability to create the conditional risk with a good
synoptic signal to also trigger widespread convection intiation from
the west with this beginning entering our CWA during this time. The
highest risk locations in our CWA will be to the west of STL
metro--in northeast and central MO. Outside of these locations and
times, this does not necessarily preclude severe wx occurrence.
Monday continues to look marginal on severe for our area, with the
highest risk locations being where the surface cold front will be as
things start to heat up for the day and this should be just east of
STL metro. The best timeframe for our CWA is a bit more sped
up--late morning and early afternoon--and this accounts for SPC`s
push of the main severe threat further east.
A localized heavy rainfall threat also continues thru Monday in this
favorable synoptic pattern, and indeed, localized heavy rainfall has
already occurred in spots scattered across our CWA, with these spots
rather small in coverage and between 2-3" over a 3-day period. No
FFA issuance with this package but the beginnings of a clearer
signal and focus are coming into play tonight and Monday morning to
perhaps justify one eventually but would like to see a bit more
favorable antecedent conditions (i.e. more rainfall today) before
this occurs as current QPF not enough to make up for this.
Preferred the higher MOS temps on Monday with SW flow and what
should be afternoon clearing, but if the rain and thicker clouds are
slower to exit, will need to chop the temps down by about 5 degrees.
For Tuesday and Wednesday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. The much
drier column and lack of upper level disturbances or surface fronts
will give us a rare two-day dry period. Temps should actually be a
bit below average with cool nighttime mins in the 40s.
The RIDGE aloft on Thursday will then gradually transition back to
an active SW flow aloft pattern for next weekend. While there
remain model discrepancies during this period, it looks to be one
where at least Climo PoPs [25-30%] are justified and more with
general agreement on moisture return and lifting mechanisms. Temps
will make a return back to average or even above average during this
time.
TES
&&
.AVIATION: (For the 12z TAFs through 12z Monday Morning)
Issued at 644 AM CDT Sun May 10 2015
A warm front is lifting slowly northward across the area. Surface
analysis from 11Z suggests the front was just south of a line from
KMBY to KPPQ, but just north of KIJX and KSPI. Front will continue
moving north this morning as low pressure strengthens and becomes
more organized over the Great Plains. IFR flight conditions will
continue to prevail along and north of the front this morning
across northern Missouri into west central Illinois, with ceilings
and visibilities improving to VFR as the wind shifts to the south
after FROPA. Widely scattered showers will be possible almost any
time today, but more widespread showers and thunderstorms are
likely later this afternoon into the evening as another
disturbance moves across the area. Some of the storms this
afternoon and evening could be strong or severe producing wind
gusts in excess of 50kts and large hail.
Unsure how the rest of the forecast period will play out. Think
the most likely scenario is lingering marginal cigs/vsbys with
periods of showers and thunderstorms continuing tonight. Think the
most likely areas for rain and storms will be along and south of
I-70.
Specifics for KSTL:
Warm front is north of the terminal at this time, so low
ceiling/visibility threat should be much diminished at Lambert for
the time being. Cannot rule out a passing shower just about any
time through early afternoon, but expect there will be far more
dry time than precipitation. Latest short-range guidance suggests
that the best chance for rain/thunderstorms will be mid to late
afternoon (probably after 20Z) as another disturbance moves over
our area from the southwest. There is a chance that the storms
could be severe with wind in excess of 50kts and/or large hail.
Unsure how the rest of the forecast period will play out. Think
the most likely scenario is lingering marginal cigs/vsbys with
periods of showers and thunderstorms continuing tonight. Think the
most likely areas for rain and storms will be along and south of
I-70. The cold front looks to move through the terminal mid to
late Monday morning; this will finally bring an end to the recent
bout of unsettled weather.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
615 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
...LOCATION OF SEVERE STORMS TODAY IS THE MAIN CHALLENGE...
EXCEPTIONALLY ACTIVE/DYNAMIC PATTERN CONTINUES OVER THE CENTRAL
UNITED STATES TODAY AS LARGE UPPER LOW SPINS OVER THE HIGH PLAINS.
WATER VAPOR IMAGERY SHOWED THE CLOSED AND WRAPPED UP CIRCULATION
DRIFTING NORTHEAST AROUND 30 KNOTS...OUT OF NORTHEAST COLORADO
AND HEADED FOR NORTHWEST NEBRASKA THIS MORNING.
A COMPLEX AND HIGHLY BAROCLINIC SURFACE PATTERN WAS ANALYZED AT
06Z WITH A CLOSED 1004MB LOW NEAR THE KANSAS-COLORADO BORDER AND A
TIGHT THERMAL AND PRESSURE GRADIENT NORTH OF THE LOW. WARM FRONT
EXTENDED FROM THE LOW EASTWARD WITH LOW TO MID 60S DEW POINTS OVER
KANSAS...AND AN INVERTED TROF EXTENDED NORTHEAST INTO THE SIOUX
CITY AREA. AIRMASS NORTH OF THE LOW WAS COLD ENOUGH FOR WIDESPREAD
SNOW IN THE WESTERN HIGH PLAINS THIS MORNING.
AS THIS PATTERN EVOLVES THROUGHOUT THE DAY...THE FEATURES BY MID-
LATE AFTERNOON APPEAR TO BE SETTING UP FOR A NEARLY CLASSIC
LOOKING COLD CORE SUPERCELL OUTBREAK. UNFORTUNATELY THERE ARE
SMALL BUT IMPORTANT DIFFERENCES IN THE SUITE OF MODEL SOLUTIONS
REGARDING WHERE THE UPPER AND SURFACE LOWS WILL TRACK...AND THESE
DIFFERENCES COULD RESULT IN THE LOCATION OF THE SUPERCELLS VARYING
BY SEVERAL COUNTIES DEPENDING ON THE SOLUTION.
THE CONSENSUS SOLUTION OF THE SREF MEAN FOR THE PLACEMENT/TRACK
OF THE UPPER AND SURFACE LOWS IS SIMILAR TO THE GOING FORECAST AS
WELL AS CURRENT TRAJECTORIES OF THE UPPER LOW. USING THE SREF MEAN
SOLUTION...THE FORECAST PATTERN IN THE 18-21Z TIME FRAME INCLUDES
THE FOLLOWING INGREDIENTS TO SUPPORT SUPERCELLS OVER NORTHEAST
NEBRASKA AND WEST CENTRAL IOWA: UPPER LOW OVER WESTERN NEBRASKA
WITH 500 MB TEMPERATURES AROUND -19C... TRIPLE POINT AND DEEP
SURFACE LOW NEAR O`NEILL...100+ KNOT UPPER LEVEL JET OVER EASTERN
NEBRASKA...WELL PRONOUNCED DRY SLOT OVER EASTERN NEBRASKA WHICH
WILL SUPPORT ML CAPE VALUES EXCEEDING 1200 J/KG AND A DIFFERENTIAL
THERMAL BOUNDARY ON THE EASTERN EDGE OF THE DRY SLOT... AND 0-1KM
SHEAR VALUES AT OR ABOVE 20 KNOTS.
HOWEVER...NUMEROUS FACTORS INCREASE THE UNCERTAINTY IN THESE
SCENARIOS INCLUDING THE ABOVE MENTIONED SPREAD IN MODEL SOLUTIONS.
IF THE MODELS DISPLAYING A NORTHERN TREND ARE CORRECT...MUCH OF
THE FORECAST AREA WOULD BE DRY AND SUNNY UNDER THE DRY SLOT WITH
THE STRONG STORM DEVELOPMENT NORTH OF THE AREA. IF THE SOUTHERN
SOLUTIONS ARE CORRECT...THE STORMS COULD DEVELOP AS FAR SOUTH AS
INTERSTATE 80 AND TRACK NORTH THROUGHOUT THE AFTERNOON. THE
FORECAST PROBABILITY OF STORMS WILL BE A FUNCTION OF THE
DISTRIBUTION OF THESE MODEL SOLUTIONS. THE MOST LIKELY AREA FOR
SEVERE STORMS WILL BE THE FAR NORTHEAST CORNER OF NEBRASKA AND
WEST CENTRAL IOWA...WITH A CHANCE FOR SEVERE STORMS EXTENDING
SOUTH TO INTERSTATE 80.
LATEST OPERATIONAL HRRR SOLUTIONS SUPPORT THUNDERSTORM
DEVELOPMENT BY EARLY AFTERNOON AND JUST EAST OF THE MISSOURI
RIVER.
THE STORMS AND SHOWERS SHOULD EXIT THE FORECAST AREA BY EVENING.
LOW AMPLITUDE UPPER RIDGING AND SURFACE HIGH PRESSURE BUILDS INTO
THE PLAINS MONDAY-TUESDAY WITH COOL BUT DRY WEATHER EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
THE UPPER PATTERN RETURNS TO BROAD SCALE TROFFING OVER THE WESTERN
US AND PACIFIC COASTAL AREAS WITH SHORTWAVES ONCE AGAIN RETURNING
TO THE PLAINS. AFTER THE DRY BEGINNING OF THE WEEK...GOOD CHANCES
FOR RAIN AND THUNDERSTORMS RETURN FOR THE PERIOD BEGINNING
WEDNESDAY NIGHT AND PERSISTING INTO THE WEEKEND.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 613 AM CDT SUN MAY 10 2015
IFR/MVFR CEILINGS EARLY THIS MORNING...WHICH SHOULD SCATTER OUT BY
16 TO 18Z. SOUTHEAST WINDS AROUND 12 KNOTS...WITH GUSTS DEVELOPING
INTO THE LOWER TO MID 20 KNOT RANGE BY 18Z. THUNDERSTORMS WILL BE
POSSIBLE PRIMARILY AT THE KOMA TAF SITE 19-23Z. WINDS THEN SHIFT
TO THE SOUTH...SOUTHWEST AND EVENTUALLY WEST NORTHWEST AS A COLD
FRONT MOVES ACROSS THE AREA. COULD SEE MVFR CEILINGS AND SPOTTY
SHOWERS DEVELOP AT KOFK BY 11/03Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...NIETFELD
LONG TERM...NIETFELD
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
835 AM PDT SUN MAY 10 2015
.SYNOPSIS...CLOUDS AND PERHAPS A SHOWER WILL PASS ACROSS NORTHERN
MOHAVE COUNTY TODAY AS MOISTURE LINGERS ON THE BACK SIDE OF A
DEPARTING STORM SYSTEM. OTHERWISE EXPECT DRY CONDITIONS WITH A
CONTINUED WARMING TREND THROUGH MONDAY. A SYSTEM WILL PASS BY
NORTHWEST OF THE AREA MONDAY NIGHT INTO TUESDAY BRINGING SOME CLOUDS
AND BREEZY CONDITIONS. ANOTHER STORM SYSTEM COULD IMPACT THE AREA
LATE NEXT WEEK WITH COOLER WEATHER AND SHOWERS POSSIBLE ON FRIDAY
AND SATURDAY.
&&
.UPDATE...
ONLY MADE MINOR ADJUSTMENTS TO TEMPS AND SKY THIS MORNING TO ACCOUNT
FOR CURRENT CONDITIONS/TRENDS. ONLY A SMALL CHANCE OF A SHOWER
ACROSS NORTHERN MOHAVE COUNTY TODAY. LAST FEW RUNS OF THE HRRR DON`T
SHOW MUCH OF ANYTHING. EXPECT A WARMER DAY THAN YESTERDAY AS RIDGING
ALOFT BUILDS OVER THE REGION. NO OTHER UPDATES ANTICIPATED THIS
MORNING.
&&
.PREVIOUS DISCUSSION...
305 AM PDT SUN MAY 10 2015
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT.
A NICE MOTHER`S DAY IS EXPECTED ACROSS THE AREA TODAY FOR THE MOST
PART AS MID/UPPER LEVEL RIDGE STARTS TO BUILD IN. THIS WILL PROMOTE
FURTHER WARMING AND LOTS OF SUNSHINE. HIGH TEMPS WILL RISE ABOUT 8-
10 DEGREES FROM SATURDAY BUT IN MOST SPOTS STILL BE A FEW DEGREES
BELOW NORMAL. THE ONLY EXCEPTION TO TODAY`S STELLAR WEATHER WILL BE
IN THE ARIZONA STRIP AREA WHERE LINGERING MOISTURE AND ENERGY ON THE
BACK SIDE OF THE HIGH PLAINS COLD LOW`S BROAD CIRCULATION TRIGGERS
SOME CLOUDS AND POSSIBLY A QUICK SHOWER OR SPRINKLE THIS AFTERNOON.
OUR ATTENTION WILL NOW TURN TO THE NEXT AREA OF LOW PRESSURE
PRESENTLY OFF THE COAST OF WASHINGTON. THIS FEATURE IS EXPECTED TO
SWING ACROSS THE PAC NW MONDAY THROUGH TUESDAY NIGHT. FOR OUR AREA
IT WILL STAY WELL ENOUGH TO THE NORTHWEST THAT ALL WE WILL SEE IS AN
INCREASE IN CIRRUS (ALTHOUGH IT DOES NOT LOOK LIKE AN OVERABUNDANCE
OF IT) AND AN INCREASE IN SOUTHWEST TO WEST WINDS BOTH MONDAY AND
TUESDAY IN THE AFTERNOON AND EVENING HOURS WITH GUSTS OF 15-25 MPH.
THE INCREASED SOUTHWEST FLOW WILL HELP TO MIX THE ATMOSPHERE BETTER
AND PUSH TEMPS BACK UP A FEW MORE DEGREES FOR MONDAY WITH NEAR
STATUS-QUO TEMPS ON TUESDAY. THIS WILL PUT HIGHS A FEW DEGREES ABOVE
NORMAL FOR A CHANGE WHICH MEANS BACK TO THE 90-102 RANGE FOR THE
LOWER ELEVATIONS OF THE MOJAVE DESERT. I SIDED WITH THE WARMER END
OF GUIDANCE BOTH DAYS FOR HIGH TEMPS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY.
DRY SOUTHWEST FLOW TO START THE PERIOD WILL GIVE WAY TO INCREASING
SOUTHERLY FLOW BY THURSDAY AS LOW PRESSURE NEARS THE WEST COAST. BY
FRIDAY THERE ARE CRITICAL MODEL DISAGREEMENTS ON THE POSITION AND
DEPTH OF THE LOW AS WELL AS A MOISTURE PLUME WRAPPING AROUND ITS
SOUTHEAST SEMICIRCLE. THIS WILL MAKE A BIG DIFFERENCE IN THE
PROBABILITY AND PLACEMENT OF SHOWERS AND THUNDERSTORMS OVER THE CWA
FRIDAY AND SATURDAY. FOR NOW HAVE KEPT THE BRUSH BROAD AND THE MAX
POPS RELATIVELY LOW DUE TO THESE UNCERTAINTIES. NEAR NORMAL
TEMPERATURES WEDNESDAY WILL START TO COME DOWN ON THURSDAY AND THEN
CRASH FRIDAY AND SATURDAY AS THE LOW MOVES IN. EXPECT BREEZY SOUTH
WINDS WEDNESDAY AND THURSDAY AND POTENTIALLY STRONGER WEST WINDS
FRIDAY AND SATURDAY /DEPENDING ON HOW FAR SOUTH THE LOW CENTER
DIGS/.
&&
.AVIATION...FOR MCCARRAN...WINDS SHOULD FAVOR TYPICAL DIURNAL
DIRECTIONAL TRENDS AT 8 KTS OR LESS THROUGH TONIGHT UNDER A
RELATIVELY CLEAR SKY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...AN ISOLATED SHRA IS POSSIBLE THIS AFTERNOON IN NORTHERN
MOHAVE COUNTY WITH SCT-BKN CLOUDS AOA 6K-10K FEET. OTHERWISE A
RELATIVELY CLEAR SKY IS EXPECTED ACROSS THE AREA. OVERALL WINDS
SHOULD MAINLY FOLLOW DIURNAL DIRECTIONAL TRENDS AT 12 KTS OR LESS
THROUGH TONIGHT.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT
REQUESTED THROUGH WEDNESDAY NIGHT. SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES LATER THIS WEEK.
&&
$$
UPDATE...PADDOCK
SHORT TERM/AVIATION...STACHELSKI
LONG TERM...MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS NORMAN OK
655 AM CDT SUN MAY 10 2015
.AVIATION...
CONVECTION THIS MORNING SHOULD MAINLY INFLUENCE OKC/OUN/PNC
THROUGH 15Z. THE RAIN SHOULD ALSO HELP TO IMPROVE IFR CONDITIONS
AT THESE SITES. A COLD FRONT WILL SWEEP ACROSS THE AREA THIS
MORNING INTO TONIGHT. THE FRONT MAY ALSO HELP WITH THE DEVELOPMENT
OF STORMS LATER THIS AFTERNOON...MAINLY AT LAW/OKC/OUN.
OTHERWISE...LOW CEILINGS AND FOG AT CSM/GAG/WWR SHOULD IMPROVE
BY 14Z.
&&
.PREV DISCUSSION... /ISSUED 430 AM CDT SUN MAY 10 2015/
DISCUSSION...
YET ANOTHER ROUND OF CONVECTION IS SET TO MOVE INTO PART OF
WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA OVER THE NEXT SEVERAL
HOURS. THE HRRR HAS BEEN FAIRLY CONSISTENT IN MOVING THIS COMPLEX
ACROSS AREAS SOUTH AND EAST OF I-44 THROUGH THE MID TO LATE
MORNING...WITH ADDITIONAL STORMS IN SOUTHEAST OKLAHOMA THIS
AFTERNOON. MOST MEDIUM RANGE MODELS ARE SIMILAR WITH THE
HRRR...BUT CONTINUE CONVECTION OVER SOUTH CENTRAL AND SOUTHEAST
OKLAHOMA INTO THE AFTERNOON/EVENING. AREAS ALONG AND SOUTHEAST OF
SEMINOLE...PAULS VALLEY AND HENRIETTA...TEXAS MAY SEE ANOTHER 2 TO
4 INCHES OF RAIN THROUGH THE AFTERNOON/EVENING WHICH WILL RESULT
IN SIGNIFICANT FLASH FLOODING. THE MAIN HAZARDS WITH THE MORNING
CONVECTION WILL BE LARGE HAIL...AND FLOODING RAINFALL.
DEPENDING ON HOW MUCH CONVECTION LINGERS OVER SOUTHEAST
OKLAHOMA...ADDITIONAL THUNDERSTORMS MAY DEVELOP ACROSS NORTH
CENTRAL...CENTRAL AND SOUTHWEST OKLAHOMA AS A COLD FRONT
APPROACHES...SIMILAR TO THE 06Z NAM. INSTABILITY AND SHEAR WILL
SUPPORT THE RISK OF VERY LARGE HAIL AND DAMAGING WINDS.
A COLD FRONT WILL SWEEP ACROSS ALL OF OKLAHOMA AND WESTERN
NORTH TEXAS BY EARLY MONDAY...WHICH WILL BRING A MUCH NEEDED
BREAK FROM SEVERE STORMS AND FLOODING RAIN. ANOTHER SHORT WAVE
TROUGH IS FORECAST TO LIFT ACROSS THE CENTRAL PLAINS ON
WEDNESDAY...WITH ANOTHER ACTIVE SOUTHWEST FLOW PERIOD FROM FRIDAY
INTO NEXT WEEKEND.
FOR NOW...WILL LEAVE THE FLOOD WATCH THE SAME...BUT SHOULD BE
ABLE TO REMOVE NORTHWEST PARTS OF THE WATCH LATER THIS AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 76 51 70 50 / 60 40 0 0
HOBART OK 78 49 70 48 / 20 10 0 0
WICHITA FALLS TX 78 55 72 51 / 70 20 10 0
GAGE OK 74 43 68 43 / 0 10 0 0
PONCA CITY OK 77 48 69 45 / 50 40 0 0
DURANT OK 76 60 75 54 / 90 80 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH MONDAY MORNING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH MONDAY MORNING FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
629 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE
LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO
OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC
LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO
CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST
LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO
THE AREA BY MID TO LATE MORNING.
MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED
SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE
AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW
MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE
MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT
SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z.
TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL
INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG
RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK
SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING
VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE
RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE
LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z
WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER
AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND
EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS
THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND
DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE
RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1
EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED
TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z.
SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST
THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL
BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY
QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL
BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE
UPPER 30S TO MID 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY
ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND
COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY
STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS
THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER
ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL
ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD
REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE
MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY
SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S.
LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY
BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY
WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE
MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH
SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS
THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE
MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE
WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER
CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE
STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS
HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN
TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING
GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE
70S BY LATE IN THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 623 AM CDT SUN MAY 10 2015
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO LIFT THROUGH THE AREA
DURING THE MORNING...THEN THE ACTIVITY WILL LESSEN INTO THE
AFTERNOON. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER
20Z TODAY...AND SOME OF THESE MAY BE SEVERE THROUGH FAR
SOUTHEASTERN SOUTH DAKOTA...NORTHWESTERN IOWA...AND NORTHEASTERN
NEBRASKA THROUGH 00Z. MVFR TO SOME IFR CEILINGS WILL BE COMMON
THROUGH THE TAF PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...JH
AVIATION...JM
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
628 AM CDT SUN MAY 10 2015
.DISCUSSION...
UPDATED FOR 12Z AVIATION.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/
DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...
12Z TAFS
UPPER LEVEL DISTURBANCES WILL BRING SEVERAL ROUNDS OF SHOWERS AND
STORMS TO JBR THROUGHOUT THE PERIOD...BUT MAINLY LATER FOR
MEM...MKL AND TUP. IN THE HEAVIEST STORMS EXPECT MVFR/IFR
CONDITIONS...OTHERWISE THE SITES WILL BE VFR. STRONGER SOUTH
WINDS ANTICIPATED WITH GUSTS NEAR 20 KTS AT JBR AND MEM. WINDS
WILL SUBSIDE SOME TONIGHT...BUT REMAIN GUSTY AT MEM AND JBR.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
225 PM MST SUN MAY 10 2015
.SYNOPSIS...
NEAR NORMAL TEMPERATURES WITH PLENTY OF SUNSHINE CAN BE EXPECTED
THROUGH THURSDAY ACROSS THE DESERT SOUTHWEST. FRIDAY THROUGH SUNDAY
...ANOTHER UNSEASONABLY COOL STORM WILL ARRIVE...USHERING IN MUCH
COOLER TEMPERATURES...BREEZY CONDITIONS...AND HEIGHTENED CHANCES FOR
RAIN.
&&
.DISCUSSION...
BENIGN WEATHER ACROSS OUR FORECAST AREA THIS AFTERNOON WITH NEARLY
ZERO CLOUD COVER. SOME WEAK ECHOES HAVE DEVELOPED OVER THE RIM/WHITE
MTNS RESULTING IN SOME THUNDER. BASED ON HRRR TRENDS/FLOW NOT
EXPECTING THAT ACTIVITY TO IMPACT OUR AREA.
TAKE-HOME MESSAGE AT THIS TIME IS NEAR/ABOVE NORMAL TEMPERATURES
EARLY IN THE WEEK WILL GIVE WAY TO ANOTHER ROUND OF UNSEASONABLY
COOL AND SHOWERY WEATHER BY FRIDAY THAT WILL LAST THROUGH THE
WEEKEND.
FIRST HALF OF THE WEEK...NOT MUCH TO DISCUSS. SHORT TERM MODELS ARE
LOCKED INTO THE DEPARTING LOW AND INCOMING SHORT WAVE RIDGE YIELDING
LITTLE DIFFERENCE IN FORECAST MAX/MIN TEMP VALUES. TUESDAY COULD BE A
BIT INTERESTING AS A SHORT WAVE RIDES THE SOUTHERLY FLOW AND ADVECTS
SOME MOISTURE INTO EASTERN ARIZONA...THOUGH POTENTIAL IMPACT TO OUR
FORECAST AREA IS MINIMAL AT THIS TIME.
GLOBAL ENSEMBLE DATA AND DETERMINISTIC RUNS OF EC/GFS ARE IN REALLY
GOOD AGREEMENT ON THE BROAD DETAILS FOR FRIDAY THROUGH SUNDAY.
ANOTHER LARGE CLOSED LOW...OF WHICH THE CURRENT ENERGY IS NEAR THE
ALEUTIAN ISLANDS...WILL MOVE INTO SOCAL AND AZ FRIDAY. THERE WILL BE
A LEADING SHORT WAVE WHICH WILL LIKELY GIVE US OUR BEST CHANCE OF
RAIN...CURRENTLY TIMES TO ARRIVE DURING THE DAY FRIDAY. WE COULD SEE
SOME ENHANCED WINDS AS THE SYSTEM LAYS INTO ARIZONA...IF HUMIDITY
VALUES ARE STILL LOW WHEN THIS HAPPENS WE COULD HAVE A PERIOD OF
CRITICAL FIRE WEATHER CONDITIONS. SOMETHING TO WATCH.
BROAD TROUGHING WILL CONTINUE THROUGH THE WEEKEND. HARD TO SAY
IF/WHEN SHOWERS WILL OCCUR AS THAT/LL HINGE ON THE FINER DETAILS OF
SHORT WAVE ENERGY ROTATING AROUND THE PARENT LOW. THERE DOES SEEM TO
BE QUITE HIGH CERTAINTY THAT WE/RE IN FOR ANOTHER WEEKEND IN MAY OF
COOL TEMPS. CURRENT FORECAST HIGH TEMPS ON SATURDAY RANGE FROM 10 TO
20 DEGREES BELOW NORMAL. AN ANALYSIS OF HISTORICAL PHOENIX RECORDS
INDICATE THAT THERE HAVE ONLY BEEN FIVE INSTANCES/YEARS WHERE THE
MONTH OF MAY HAD TWO OR MORE SATURDAYS WITH A HIGH TEMP BELOW 80F
/LAST WAS IN 1971/. WITH A CURRENT FORECAST HIGH OF 78 FOR THIS
COMING SATURDAY...2015 WOULD BE THE SIXTH.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
DRY WESTERLY FLOW ALOFT PROVIDING CLEAR SKIES AND LIGHT WINDS
THROUGH MONDAY EVENING. WIND DIRECTIONS SHOULD MOSTLY FOLLOW TYPICAL
DIURNAL PATTERNS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WARM TEMPERATURES AND LOW HUMIDITY VALUES WILL BE ESTABLISHED MID-
WEEK BUT THAT WILL CHANGE BY FRIDAY AS ANOTHER UNSEASONABLY COOL
STORM SYSTEM ENTERS THE SOUTHWEST. BREEZY WINDS WILL ACCOMPANY THE
SYSTEM AS IT MOVES IN THURSDAY AND EARLY FRIDAY AND COULD COMBINE
WITH STILL DEPRESSED HUMIDITY VALUES FOR A PERIOD OF CRITICAL FIRE
WEATHER CONDITIONS. AS THE SYSTEM EASES IN LATER FRIDAY...
TEMPERATURES WILL DROP AND HUMIDITY VALUES WILL INCREASE. CHANCES
FOR WETTING RAIN...ESPECIALLY ACROSS CENTRAL ARIZONA...WILL ALSO
INCREASE. THIS WEATHER PATTERN WILL LIKELY REMAIN THROUGH THE
WEEKEND.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
931 AM MST SUN MAY 10 2015
.UPDATE...
LITTLE CHANGE IN THE FORECAST FOR TODAY. BROAD CYCLONIC FLOW REMAINS
ACROSS THE REGION AS A LARGE CLOSED LOW MOVES OUT INTO THE PLAINS
FROM THE MOUNTAIN WEST. NOTED A JET STREAK COMING DOWN THE BACK SIDE
IN THIS MORNING/S RAOBS AND MODEL INITIAL FIELDS. MOISTURE IS SCANT
THOUGH AND WITH MID-LEVELS ALREADY WARMING NOT EXPECTING MUCH IN WAY
OF SHOWER/TSTM ACTIVITY FOR OUR AREA. CU FIELDS ARE OFF TO AN EARLY
START ACROSS NORTHERN ARIZONA BUT LIMITED DEVELOPMENT AND MOVEMENT
WILL PRECLUDE US FROM SEEING MUCH IF ANY ACTIVITY. HRRR RUNS SEEM
DIALED INTO THAT SOLUTION. DID MAKE MODEST ADJUSTMENTS TO MAX TEMPS
FOR TODAY BASED ON PAST FEW HRRR RUNS...TEMPERATURES NEAR NORMAL LOOK
ON-TRACK. OVERALL A QUIET AND PLEASANT SUNDAY UNFOLDING.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM IN THE PLAINS WILL CONTINUE TO BRING BELOW
NORMAL TEMPERATURES TO THE DESERT SOUTHWEST TODAY. HIGH PRESSURE
WILL THEN ALLOW TEMPERATURES TO RETURN TO NORMAL VALUES BY EARLY NEXT
WEEK ALTHOUGH MID TO LATE WEEK TROUGHING ACROSS THE PACIFIC NORTHWEST
SHOULD PREVENT TEMPERATURES FROM CLIMBING INTO THE TRIPLE DIGITS.
THERE WILL ALSO BE AN INCREASING CHANCE OF PRECIPITATION LATE IN THE
WEEK AS A TROUGH APPROACHES THE AREA.
&&
.DISCUSSION...
UPPER LEVEL LOW PRESSURE OVER COLORADO REMAINS THE DOMINANT WEATHER
FEATURE ACROSS THE WESTERN CONUS...AND CONTINUES TO USHER BELOW
NORMAL TEMPERATURES INTO THE REGION. LATE DAY SHOWERS AND CU ACROSS
THE REGION HAVE LONG SINCE DISSIPATED...BUT ONE FINAL SHORTWAVE
TROUGH WAS MAKING ITS WAY THROUGH NORTHWEST ARIZONA THIS MORNING.
REGIONAL RADAR MOSAIC INDICATED VERY ISOLATED SHOWERS SOUTH OF LAS
VEGAS EARLIER THIS MORNING...BUT EVEN THESE HAVE STARTED DYING OFF
SINCE 08Z. THIS HAS RESULTED IN ANOTHER MORNING OF MOSTLY CLEAR
SKIES...LOW DEWPOINTS...AND UNSEASONABLY COOL TEMPERATURES ACROSS THE
DESERTS. REGIONAL OBS AS OF 09Z REVEAL TEMPERATURES IN THE MID 50S TO
LOWER 60S...WHICH IS ALREADY 5-10 DEGREES BELOW NORMAL FOR MAY 10TH.
THE AFOREMENTIONED SHORTWAVE WILL QUICKLY MOVE THROUGH THE AREA
TODAY...ONLY BRINGING A SLIGHT INCREASE IN MID CLOUDS TO THE AREA.
PRECIP CHANCES ARE LARGELY NIL TODAY ALTHOUGH I CAN`T RULE OUT A
STRAY SHOWER OVER THE MOUNTAINS NORTH/EAST OF PHOENIX.
ACCORDINGLY...I HAVE RETAINED 5-10 POPS EAST OF GLOBE. ANY SHOWERS
THAT DEVELOP WILL DISSIPATE QUICKLY WITH THE LOSS OF DAYTIME
HEATING...NOT TO MENTION INCREASING ANTICYCLONIC FLOW ALOFT AS
RIDGING BEGINS TO STRENGTHEN ACROSS SOUTHERN CALIFORNIA.
THE UPPER RIDGE WILL DEVELOP AND STRENGTHEN ACROSS SOUTHERN
CALIFORNIA AND ARIZONA MONDAY THROUGH TUESDAY WITH TEMPERATURES
QUICKLY RETURNING TO NORMAL VALUES. BIAS CORRECTED CONSENSUS GUIDANCE
HAS BEEN SUGGESTING HIGHS IN THE MID 90S MONDAY THROUGH WEDNESDAY AND
THIS IS STILL THE CASE WITH TODAY`S 00Z VALUES. VERY HIGH
CONFIDENCE/LITTLE CHANGE IN THE FORECAST THROUGH MID WEEK.
THINGS TURN A BIT MORE INTERESTING AS WE GET CLOSER TO THURSDAY...AND
CERTAINLY BY FRIDAY INTO THE WEEKEND. ENSEMBLE MEANS OVER THE PAST
FEW DAYS HAVE ADVERTISED PERSISTENT TROUGHING ACROSS THE WESTERN
CONUS AS AN UPPER LOW MOVES THROUGH THE PAC NW INTO THE GREAT
BASIN. DETERMINISTIC GUIDANCE HAS BEEN IN AGREEMENT FOR THE MOST
PART DURING THIS LATE-WEEK PERIOD...ALTHOUGH NOT SURPRISINGLY EACH
RUN OF EACH MODEL HAS VARIED SOMEWHAT UP UNTIL RECENTLY. YESTERDAY`S
12Z AND TODAY`S 00Z DETERMINISTIC GFS AND ECMWF HAVE COME INTO MUCH
BETTER AGREEMENT...AND SUGGEST A SUBSTANTIAL INCREASE IN BL MOISTURE
LATE IN THE WEEK COINCIDENT WITH THE ARRIVAL OF A VERY POTENT 500MB
SHORTWAVE TROUGH. GFS IN PARTICULAR INDICATES PWATS CLIMBING INTO THE
0.8 TO 1.0 INCH RANGE ON FRIDAY...WHICH WOULD BE WELL INTO THE 99TH
PERCENTILE OF OBSERVED PWATS ACROSS ARIZONA FOR THE MIDDLE OF MAY.
WITH A PROLONGED RESIDENCE TIME OVER THE EASTERN PACIFIC...IT WILL
CERTAINLY HAVE MORE THAN ENOUGH TIME TO ADVECT MOISTURE INTO THE
AREA AND THE 00Z NAEFS AGREES /INTEGRATED WV TRANSPORT CLIMBS WELL
INTO THE 90TH PERCENTILE ON FRIDAY/. ECMWF IS A BIT SLOWER AND
SLIGHTLY DRIER...BUT HAS THE SAME BASIC IDEA. I WENT AHEAD AND
INCREASED POPS ABOVE CLIMO /INTO THE 10-30 PERCENT RANGE/ FOR FRIDAY
AND SATURDAY ALTHOUGH THE EXACT TIMING WILL NEED TO BE NAILED
DOWN...AS ITS UNLIKELY WE`D SEE PERSISTENT SHOWERS FOR 2 STRAIGHT
DAYS. ALSO TOOK A BIG SWING DOWNWARD WITH TEMPERATURES...CONSENSUS
GUIDANCE YIELDS HIGHS IN THE UPPER 70S AND THIS SEEMS MORE THAN
REASONABLE.
OVERALL...CONFIDENCE IS HIGH IN THE DEVELOPMENT OF A
COOL/WET LATE-WEEK PATTERN. CONFIDENCE IN EXACT TIMING OF THE ONSET
OF SHOWERS AND STORM TOTAL PRECIP AMOUNTS IS LOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
DRY WESTERLY FLOW ALOFT PROVIDING CLEAR SKIES AND LIGHT WINDS
THROUGH MONDAY AFTERNOON. WIND DIRECTIONS SHOULD MOSTLY FOLLOW
TYPICAL DIURNAL PATTERNS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE AND ITS ASSOCIATED WARMTH WILL RETURN TO THE DISTRICTS
EARLY NEXT WEEK. THIS WILL RESULT IN TEMPERATURES RETURNING TO NEAR
NORMAL VALUES WITH DRY CONDITIONS. MINIMUM AFTERNOON HUMIDITY LEVELS
WILL FALL INTO THE SINGLE DIGITS AND TEENS WITH FAIR OVERNIGHT
RECOVERY. BY THE MIDDLE PART OF THE WEEK ANOTHER SERIES OF PACIFIC
STORMS WILL MOVE INTO THE WESTERN CONUS AND GENERATE BREEZY TO
LOCALLY WINDY CONDITIONS FOR THE FIRE WEATHER ZONES. FIRST ON
THURSDAY...LOWERING DAYTIME HUMIDITIES COUPLED WITH STRONG WINDS MAY
DEVELOP AREAS OF CRITICAL FIRE WEATHER CONDITIONS OVER PORTIONS OF
SOUTH-CENTRAL AZ. NEXT FOR THE LATE WEEK/NEXT WEEKEND...TEMPERATURES
WILL BE BEGIN TO COOL AND DEWPOINTS COME UP SLIGHTLY AS A LARGER AND
COOLER PACIFIC STORM IS NOW FORECAST INTO THE AREA.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ/LEINS
AVIATION...INIGUEZ
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
323 PM MDT SUN MAY 10 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 323 PM MDT SUN MAY 10 2015
NORTH TO NORTHWESTERLY FLOW CONTINUES ON THE BACK SIDE OF THE LOW
PRESSURE SYSTEM THAT BROUGHT ALL THE SNOW AND RAIN YESTERDAY. THE
NAM12/EC/GFS ALL SHOW A SHORTWAVE MOVING OVER THE FORECAST AREA
THIS EVENING BRINGING ANOTHER ROUND OF PRECIP WITH MOUNTAINOUS
TERRAIN SEEING MORE SNOWFALL. HOWEVER...THESE MODELS DID NOT
INITIALIZE WELL THIS MORNING AND ARE CURRENTLY OVERDOING
QPF/PRECIP. MEANWHILE...THE HRRR AND RAP13 APPEARED TO BE DOING
MUCH BETTER WITH NAILING PRECIP AND WILL FOLLOW THESE SOLUTIONS
IN THE SHORT TERM.
FOR THIS AFTERNOON THEN...WITH COLD AIR ADVECTING IN...MINOR
INSTABILITY EXISTS AND WITH CLOUDS BREAKING UP SOME...A FEW
RUMBLES POSSIBLE THIS AFTN MAINLY FOR ERN UT AND SWRN CO. FOR THIS
EVENING AND TONIGHT...THE RAP13 SHOWS ALMOST NO PRECIP WHILE THE
HRRR DOES SHOW THE WAVE MOVING THROUGH BUT PRECIP AMTS ARE LIGHT
AS THE DISTURBANCE QUICKLY MOVES OVERHEAD. PUT ISOLD/SCTD PRECIP
FOR NORTHERN VALLEYS AND ALL HIGHER TERRAIN TONIGHT.
NORTHERLY FLOW WILL ALSO BRING COOLER TEMPERATURES TO THE REGION
WITH NORTHERN VALLEYS AND SOUTHERN VALLEYS SEEING FREEZING OR JUST
BELOW FREEZING TEMPS. THESE TEMPS WILL BOTTOM OUT JUST BEFORE
SUNRISE SO OPTED TO NOT ISSUE ANY FREEZE WARNINGS. HIGH PRESSURE
WILL THEN BUILD IN BRINGING A PLEASANT START TO THE WORK WEEK.
ANOTHER LOW DRIFTING SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST
WILL CAUSE A RIDGE TO BUILD OVER THE REGION. DECENT WARM AIR
ADVECTION (WAA) COMBINED WITH A DRY SOUTHWEST FLOW WILL BRING MORE
QUIESCENT WEATHER TO FORECAST AREA MONDAY. HOWEVER...12Z GFS DID
SUGGEST THERE MAY BE ENOUGH RESIDUAL MOISTURE OVER THE EASTERN
UINTA MOUNTAINS TO FUEL A FEW DIURNAL SHOWERS/THUNDERSTORMS.
DESPITE WARMING...AFTERNOON HIGHS WILL REMAIN SEVERAL DEGREES
BELOW NORMAL.
DRY CONDITIONS PERSIST MONDAY NIGHT THOUGH THE RIDGE AXIS WILL
SHIFT EAST OF THE CONTINENTAL DIVIDE BY 12Z/TUE AS THE NORTHWEST
PACIFIC LOW PRESSURE SYSTEM MOVES ASHORE OVER SOUTHWEST OREGON.
OVERNIGHT LOWS WILL FALL TO NEAR NORMAL LEVELS AS LOSS OF CLOUD
COVER IS BALANCED BY WAA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 323 PM MDT SUN MAY 10 2015
THE LOW REMAINS NEARLY STATIONARY DURING THE DAY ON TUESDAY AS A
STRONG VORTICITY LOBE MOVES THROUGH ITS BASE. MEANWHILE...
ISENTROPIC FIELDS INDICATED A SURGE OF LOW LEVEL MOISTURE
ORIGINATING FROM THE GULF OF MEXICO WILL MOVE NORTHWARD OVER THE
CONTINENTAL DIVIDE FUELING SCATTERED SHOWERS AND THUNDERSTORMS
DURING THE AFTERNOON. OVER NORTHEAST UTAH...MODELS DIVIDED ON
WHETHER ENOUGH MOISTURE WILL REMAIN OVER THE EASTERN UINTAS TO
GENERATE MOIST CONVECTION DURING THE AFTERNOON. GIVEN MODEL
DIFFERENCES WILL CONTINUE WITH LOW CHANCES OVER THE EASTERN UINTA
MOUNTAINS. AS WAA ADVECTION CONTINUES...AFTERNOON HIGHS ARE
EXPECTED TO CONTINUE TO INCREASE WITH LATEST GUIDANCE INDICATING
HIGHS AROUND 5 DEGREES ABOVE NORMAL.
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO TUESDAY EVENING AND
MAY PERSIST OVER THE SAN JUAN MOUNTAINS LATE INTO THE NIGHT AS A
SHORTWAVE IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHWEST.
EXPECT ANOTHER ROUND OF DIURNALLY DRIVEN MOIST CONVECTION
WEDNESDAY AFTERNOON/EVENING WITH SOME ENHANCEMENT ACROSS THE SOUTH
ASSOCIATED WITH THE SHORTWAVE TROUGH MENTIONED PREVIOUSLY. ON
THURSDAY...THE TROUGH ALONG THE PACIFIC NORTHWEST SLIPS SOUTHWARD
ALLOWING MOISTURE TO CONTINUE STREAMING NORTHWARD OVER THE DIVIDE.
AS A RESULT...EXPECT SIMILAR CONDITIONS TO WEDNESDAY WITH STORMS
LARGELY ANCHORED TO THE COLORADO MOUNTAINS. AFTERNOON HIGHS WILL
CONTINUE TO RUN SEVERAL DEGREES ABOVE NORMAL AS WAA IN SOUTHWEST
FLOW PERSISTS.
HOWEVER...THE WARM PERIOD ENDS FRIDAY AS A SLUG OF PACIFIC
MOISTURE DRIVEN ACROSS THE SOUTHWEST BY A VORTICITY LOBE EJECTED
FROM THE LOW CENTERED OVER SAN FRANCISCO COMBINES WITH GULF
MOISTURE ALREADY IN PLACE. DIABATIC COOLING ASSOCIATED WITH
INCREASED CLOUDS AND SHOWERS WILL DRIVE COOLING WITH HIGHS
DROPPING OFF BY ABOUT 10 DEGREES RELATIVE TO THURSDAY/S FORECAST
HIGHS WITH READINGS COMING IN ABOUT 5 DEGREES BELOW NORMAL. MODELS
IN FAIRLY GOOD AGREEMENT FOR THE WEEKEND WITH BOTH THE GFS AND
ECMWF DEPICTING ANOTHER MOIST...COOL...AND UNSETTLED PERIOD AS THE
LOW MOVES FROM THE WEST COAST AND ACROSS THE FORECAST AREA
EVENTUALLY REACHING THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON MONDAY)
ISSUED AT 1100 AM MDT SUN MAY 10 2015
KASE...KEGE...AND KTEX WILL LIKELY SEE THE BIGGEST IMPACT TODAY
WITH CLOUDS AND PRECIP OFF AND ON THROUGH THE DAY. VFR/MVFR WILL
BE COMMON. REMAINING TAF SITES WILL SEE CONDITIONS SLOWLY IMPROVE
FROM SOUTH TO NORTH THROUGH THE DAY WITH VFR EXPECTED FOR THE MOST
PART. SOME FOG IS POSSIBLE TOWARDS DAYBREAK BUT NOT QUITE CONFIDENT
ENOUGH YET TO INCLUDE IN TAFS. MTN OBSCURATIONS WILL CONTINUE INTO
THE OVERNIGHT PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...TGR/NL
LONG TERM...NL
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1058 AM MDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1048 AM MDT SUN MAY 10 2015
SHORT RANGE GUIDANCE...THE HRRR AND RAP...CONTINUE TO DOWNPLAY
PRECIP FROM THIS NEXT WAVE THAT IS PROGGED TO MOVE OVER THE AREA
THIS EVENING. RAP HAS ALMOST NO PRECIP WHILE HRRR DOES SHOW SOME
QPF BUT VERY QUICK MOVING AND LIGHT. NAM AND GFS GUIDANCE NOT
PANNING OUT SO FAR THIS MORNING AS THEY BOTH PAINT MUCH MORE
WIDESPREAD PRECIP THAN IS OCCURRING. ALL ROADS ARE NOW WET WITH
LITTLE TO NO SNOW OR ICE SEEN ON WEBCAMS. WILL FOLLOW HRRR/RAP
LEAD AND UPDATE FORECAST AND LOWER POP/QPF AMTS...ALSO WENT AHEAD
AND DROPPED HIGHLIGHTS. EXPECT PLENTY OF CLOUDS FOR THE
MTNS...REMAINING AREAS WILL SEE CLOUDS BREAKING UP THROUGH THE
AFTERNOON. AREAS SOUTH AND WEST MAY SEE PARTLY CLOUDY SKIES.
UPDATE ISSUED AT 857 AM MDT SUN MAY 10 2015
CLOUDS AND PRECIPITATION CONTINUE ACROSS MUCH OF THE CWA AS LOW
PRESSURE...NOW CENTERED OVER THE PLAINS...CONTINUES MOVING NEWRD.
SHORT RANGE MODELS CONTINUE PICKING UP ON SHORTWAVE MOVING ACROSS
THE AREA LATER THIS AFTERNOON AND EVENING WHEN THE COLDEST TEMPS
START DROPPING DOWN FROM THE NORTH. ANY ICE OR SNOW ON ROADS
SHOULD HAVE MELTED BY NOW BUT WITH ONGOING PRECIP AND LOWERED
VISIBILITIES...THINK ENOUGH OF AN IMPACT TO KEEP HIGHLIGHTS GOING.
WILL KEEP AN EYE ON NEXT DISTURBANCE AND HOW IT EVOLVES AS THE
DAY PROGRESSES.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 323 AM MDT SUN MAY 10 2015
AS UPPER LEVEL LOW PRESSURE OVER NE CO LIFTS INTO THE NRN PLAINS
SUNDAY...A WEAK SHORTWAVE TROUGH DROPS SOUTH FROM MT INTO EASTERN
UT BY SUNDAY EVENING AND THEN EAST ACROSS CO SUNDAY NIGHT. MID AND
UPPER LEVEL MOISTURE ASSOCIATED WITH TROWAL PATTERN OF DEPARTING
LOW HANGS AROUND THRU SUNDAY...ESPECIALLY ACROSS THE NORTHERN HALF
OF THE AREA AND WILL BE AVAILABLE FOR THE MONTANA SHORTWAVE TO
USE TO DEVELOP ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS FOR
THE LATTER HALF OF SUNDAY. SNOW LEVELS WILL REMAIN LOW...ONLY
REBOUNDING TO AROUND 7500 FEET NORTH TO 9000 FEET SOUTH SUNDAY
AFTERNOON...SO ADDITIONAL ACCUMULATIONS OF SNOWFALL LIKELY FOR THE
HIGHER ELEVATIONS. WILL LEAVE THE WINTER STORM WARNINGS/ADVISORIES
AS THERE ARE FOR THE EARLY MORNING HOURS TO KEEP AWARENESS HIGH
FOR HAZARDOUS TRAVEL...BUT EXPECT THAT AT LEAST SOME OF THE
HEADLINES WILL BE ABLE TO BE DROPPED BY MIDDAY.
UPPER LEVEL RIDGE BUILDS ACROSS THE REGION MONDAY BRINGING A
RESPITE FROM THE WET WEATHER...ABUNDANT SUNSHINE AND MILDER
TEMPERATURES. HOWEVER...CANNOT RULE OUT ISOLATED CONVECTION OVER
THE TYPICAL DIURNALLY DRIVEN FAVORABLE SPOTS IN THE MOUNTAINS.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM MDT SUN MAY 10 2015
UNSETTLED CONDITIONS WILL CONTINUE FOR MUCH OF THE WEEK AS WE SEE
ANOTHER SURGE OF MOISTURE WORK NORTH TUESDAY...THEN WE START TO
WORK ON DAILY RECYCLING OF LOW LEVEL MOISTURE LEFT OVER THE REGION
THROUGH THURSDAY. EXPECTED MAINLY DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS...CONFINED TO THE HIGHER TERRAIN WITH A FEW CELLS
TRAVELING OVER THE VALLEYS LATE IN THE DAY. TEMPS WILL BE JUMPING
BACK TO ABOVE NORMAL READINGS BY MIDWEEK IN STRENGTHENING SOUTHWEST
FLOW. ALL OF THIS IS AHEAD OF YET ANOTHER WEEKEND STORM THAT WILL
BEGIN TO IMPACT THE FORECAST AREA FRIDAY AFTERNOON AS WE SEE A
STRONGER SURGE OF EASTERN PACIFIC MOISTURE WORK NORTH OFF THE BAJA
AND INTO WESTERN COLORADO. INCREASINGLY DIFLUENT FLOW AHEAD OF THE
DIGGING LOW THAT SLIDES INTO THE GREAT BASIN ON SATURDAY PROMISES
FAIRLY WIDESPREAD PRECIPITATION BEGINNING FRIDAY NIGHT AND
CONTINUING INTO SUNDAY. GFS AND ECMWF IN MUCH BETTER AGREEMENT
WITH THIS LATEST MODEL RUN...TAKING THE NEW CLOSED LOW AND LIFTING
IT NORTH NORTHEAST INTO WYOMING BY SUNDAY MORNING AND INTO THE
WESTERN DAKOTAS BY SUNDAY NIGHT. WITH SOME MODEL CONSISTENCY
DEVELOPING...CONFIDENCE INCREASING A BIT AND WILL RAMP POPS UP A
BIT...BUT STILL BELOW LIKELY THRESHOLDS AS WE WAIT FOR A LITTLE
RUN TO RUN CONSISTENCY. TEMPS EXPECTED TO DROP BACK BELOW NORMAL
OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON MONDAY)
ISSUED AT 1100 AM MDT SUN MAY 10 2015
KASE...KEGE...AND KTEX WILL LIKELY SEE THE BIGGEST IMPACT TODAY
WITH CLOUDS AND PRECIP OFF AND ON THROUGH THE DAY. VFR/MVFR WILL
BE COMMON. REMAINING TAF SITES WILL SEE CONDITIONS SLOWLY IMPROVE
FROM SOUTH TO NORTH THROUGH THE DAY WITH VFR EXPECTED FOR THE MOST
PART. SOME FOG IS POSSIBLE TOWARDS DAYBREAK BUT NOT QUITE CONFIDENT
ENOUGH YET TO INCLUDE IN TAFS. MTN OBSCURATIONS WILL CONTINUE INTO
THE OVERNIGHT PERIOD.
&&
.HYDROLOGY...
ISSUED AT 323 AM MDT SUN MAY 10 2015
MOST RIVERS IN WESTERN COLORADO REMAIN WELL BELOW BANKFULL STAGES
ALTHOUGH RECENT RAINFALL INCREASED FLOWS IN THE RIVERS. EVEN SO...A
FEW SMALLER STREAMS AND CREEKS DID INCREASE TO NEAR BANKFULL. THE
UPPER YAMPA RIVER IS AT BANKFULL FROM THE COMBINATION OF RECENT
RAIN AND SNOW MELT AND WILL REMAIN NEAR OR SLIGHTLY ABOVE BANKFULL
THROUGH THE REMAINDER OF THE WEEKEND. THE UPPER HEADWATERS OF THE
MAINSTEM RIVERS...SMALL STREAMS AND CREEKS COULD ALSO SEE ANOTHER
INCREASE IN FLOWS FROM ADDITIONAL PRECIPITATION TODAY AND TONIGHT.
THE MAINSTEM RIVERS WILL REMAIN BELOW BANKFULL LEVELS BUT COULD
ALSO SEE INCREASES IN FLOWS. LOCALIZED FLOODING IS POSSIBLE UNDER
THE STRONGEST RAINFALL DUE TO SATURATED SOILS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...TGR
SHORT TERM...BM
LONG TERM...JDC
AVIATION...TGR
HYDROLOGY...JDC/AS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT SUN MAY 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 417 PM EDT SUN MAY 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL
LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN
NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN
PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND
A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME
PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW
CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS
OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA.
HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY
AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA.
TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN
UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER
FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT
WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF
DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG
ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD
OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE
TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO
THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY
OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY
TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY
MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT
IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER
CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND
E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS...
LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE
FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF
RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG
SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL.
LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO
THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW
HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT
CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS
BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT
LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE
WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS
UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR
60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE
SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM EDT SUN MAY 10 2015
MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING
TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY
FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS
MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES
OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW
WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO
THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS
UPPER MI THROUGH MUCH OF THE DAY TUESDAY.
COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE
UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE
FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY
TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT
COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF
WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL.
AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL
IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID
WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID
MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY
GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN.
LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE
INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A
SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT
THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY
NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF
HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY
AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT.
THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND
COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES
THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC.
ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN
THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON
THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE
CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND
FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE
POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS
REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN MAY 10 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL
NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS
LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT
KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH
BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR
CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA
OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE
AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD
OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS
WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON
MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF
PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY
THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A
TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE
FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY
LATE MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SUN MAY 10 2015
TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF
MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN
ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A
RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE
SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN
PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL
ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR
WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES
SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL
DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS
MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE
UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS
E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
249 PM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM EDT SUN MAY 10 2015
MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING
TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY
FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS
MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES
OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW
WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO
THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS
UPPER MI THROUGH MUCH OF THE DAY TUESDAY.
COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE
UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE
FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY
TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT
COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF
WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL.
AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL
IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID
WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID
MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY
GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN.
LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE
INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A
SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT
THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY
NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF
HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY
AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT.
THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND
COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES
THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC.
ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN
THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON
THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE
CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND
FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE
POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS
REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN MAY 10 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL
NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS
LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT
KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH
BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR
CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA
OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE
AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD
OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS
WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON
MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF
PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY
THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A
TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE
FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY
LATE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 PM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN MAY 10 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL
NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS
LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT
KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH
BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR
CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA
OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE
AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD
OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS
WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON
MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF
PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY
THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A
TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE
FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY
LATE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
433 PM CDT Sun May 10 2015
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CDT Sun May 10 2015
Have heavily leaned towards the afternoon runs of the HRRR for
convective trends heading into the early evening hours. N-S band of
convection is plowing east at 40-45 kts, and will likely be exiting
eastern sections of our CWA shortly after 00z. After an early
evening lull in activity convection should then return to the
CWA...with threat likely a combination of the activity now
increasing along cold front over eastern KS as well as convection
redeveloping just north of Red River.
Believe that this SE OK activity will be the dominate convection
for our area overnight, as current activity will be intensifying
the low level boundary draped across the ARKLATEX, with this dome
of rain-cooled air providing lift to increasing low level jet that
will be transporting very moist air into the region from the
southern Plains. This area will also be in a favorable area of
upper level divergence tied to RRQ of upper level jet.
Once current line of convection exits area, uncertain about
additional severe weather potential overnight. Current activity
as well as latest upstream convection will be putting a big bite
in the instability that will be available, although large scale
shear of 30-50kts still certainly suggests some severe weather
potential. In addition...while some decent rainfalls are likely
over southern sections of the CWA, believe the aforementioned
outflow boundary will keep the heaviest rain threat anchored over
AR...and south of our CWA.
Truett
.LONG TERM: (Monday through Next Sunday)
Issued at 431 PM CDT Sun May 10 2015
Convection should press east and exit the region during the day
on Monday as cold front pushes across the CWA. I`ve held onto much
higher PoPs than guidance for the early part of the morning on the
western edge of the expected precip shield (generally from near
Cuba thru STL to near Carlinville), but then quickly wind them
down to the SE of STL during the late morning and early afternoon
hours. Any severe weather potential will be strongly tied to
morning convection trends, but SWODY2 still looks reasonable that
greatest threat will be in our far southeast counties, where the
AMS will stand at least some chance of destabililzing before fropa
occurs.
As unseasonably strong upper level low spins its way across the
Great Lakes Monday night and Tuesday, it will drag much cooler air
into the area. This should result in a dry Tuesday with temps a
bit below average, as highs will primarily be in the 60s. Ridging
in the wake of the departing low will mean more tranquil weather
by midweek, with temperatures moderating into the 70s.
Another upper level system will mean a return of unsettled weather
heading into the latter half of the week. There is a large
discrepency in the medium range solutions regarding the location and
movement of this feature especially heading into next weekend, but
with all solutions suggesting a frontal boundary remaining over
the area forecast will mention a chance of thunderstorms in most
areas during the Thursday-Sunday time frame.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1222 PM CDT Sun May 10 2015
Line of thunderstorms will reach KCOU by around 20Z, then KSTL by
22Z. Expect thunder threat to last about 2 hours, but limited
instability will preclude widespread threat of any severe weather. Latest
model runs continue to show an area of rain, with little to no
thunder expected, will form overnight and move through the TAF
sites until around 12Z. Ceilings may drop to 2000 feet as rain
ends early Monday morning. Ceilings will then improve as drier
air moves in and winds back to westerly by late Monday morning.
Specifics for KSTL: VFR conditions until around 22Z when an line
of thunderstorms will move through KSTL. Thunder threat will last
about 2 hours, then an area of rain will move in overnight. No
appreciable instability with this area of rain, so thunder threat
is small. Rain will likely end by around 12Z Monday. Ceilings may
drop to around 2000 feet as the rain ends, however winds will
continue to back, bringing in a drier airmass which will help
ceilings lift and scatter out by 18Z Monday.
Browning
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 66 74 52 69 / 80 80 5 0
Quincy 61 68 46 65 / 70 30 5 0
Columbia 57 69 47 68 / 70 20 5 0
Jefferson City 58 71 47 69 / 70 20 5 0
Salem 68 76 53 68 / 90 80 10 0
Farmington 63 75 50 69 / 80 80 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1237 PM CDT Sun May 10 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 355 AM CDT Sun May 10 2015
Warm front just north of the I-70 corridor will continue advancing
slowly northward this morning and should be well north of the
forecast area into Iowa and northern Illinois by 17-18Z. Deep
moisture combined with another passing MCV and low level warm
advection will continue to produce scattered showers and the
occasional thunderstorm this morning. The primary shortwave over
northeast Colorado is finally moving, opening up, and being drawn up
into the mean flow. Should see the surface low associated with the
wave tighten up and move from western Kansas into northeast Nebraska
or northwest Iowa by early evening. Short range guidance suggests
there will be another wave of rain and thunderstorms this afternoon
well ahead of the cold front, probably triggered by another MCV
generated by the convection now occurring over central Texas. NAM
and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm
sector across the area for this MCV to work with. Add in 40+ kts of
0-6km shear and severe thunderstorms look more likely today than the
past couple of days. Not sure what the mode of thunderstorm
development will ultimately be, but would a few discrete rotating
storms will be possible before everything congeals into clusters or
broken lines.
Carney
.LONG TERM: (Tonight through Saturday)
Issued at 355 AM CDT Sun May 10 2015
Southwest flow aloft will persist for much of this period, only
ending when the main TROF ejects thru our region. Thrown into the
mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system currently over the central High Plains. This will yield high
PoPs thru Monday.
Severe storm potential still on track today and tonight, with the
best timeframe from mid-afternoon into mid-evening as better bulk
shear enters the fray during this time and there should still be
enough instability to create the conditional risk with a good
synoptic signal to also trigger widespread convection intiation from
the west with this beginning entering our CWA during this time. The
highest risk locations in our CWA will be to the west of STL
metro--in northeast and central MO. Outside of these locations and
times, this does not necessarily preclude severe wx occurrence.
Monday continues to look marginal on severe for our area, with the
highest risk locations being where the surface cold front will be as
things start to heat up for the day and this should be just east of
STL metro. The best timeframe for our CWA is a bit more sped
up--late morning and early afternoon--and this accounts for SPC`s
push of the main severe threat further east.
A localized heavy rainfall threat also continues thru Monday in this
favorable synoptic pattern, and indeed, localized heavy rainfall has
already occurred in spots scattered across our CWA, with these spots
rather small in coverage and between 2-3" over a 3-day period. No
FFA issuance with this package but the beginnings of a clearer
signal and focus are coming into play tonight and Monday morning to
perhaps justify one eventually but would like to see a bit more
favorable antecedent conditions (i.e. more rainfall today) before
this occurs as current QPF not enough to make up for this.
Preferred the higher MOS temps on Monday with SW flow and what
should be afternoon clearing, but if the rain and thicker clouds are
slower to exit, will need to chop the temps down by about 5 degrees.
For Tuesday and Wednesday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. The much
drier column and lack of upper level disturbances or surface fronts
will give us a rare two-day dry period. Temps should actually be a
bit below average with cool nighttime mins in the 40s.
The RIDGE aloft on Thursday will then gradually transition back to
an active SW flow aloft pattern for next weekend. While there
remain model discrepancies during this period, it looks to be one
where at least Climo PoPs [25-30%] are justified and more with
general agreement on moisture return and lifting mechanisms. Temps
will make a return back to average or even above average during this
time.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1222 PM CDT Sun May 10 2015
Line of thunderstorms will reach KCOU by around 20Z, then KSTL by
22Z. Expect thunder threat to last about 2 hours, but limited
instability will preclude widespread threat of any severe weather. Latest
model runs continue to show an area of rain, with little to no
thunder expected, will form overnight and move through the TAF
sites until around 12Z. Ceilings may drop to 2000 feet as rain
ends early Monday morning. Ceilings will then improve as drier
air moves in and winds back to westerly by late Monday morning.
Specifics for KSTL: VFR conditions until around 22Z when an line
of thunderstorms will move through KSTL. Thunder threat will last
about 2 hours, then an area of rain will move in overnight. No
appreciable instability with this area of rain, so thunder threat
is small. Rain will likely end by around 12Z Monday. Ceilings may
drop to around 2000 feet as the rain ends, however winds will
continue to back, bringing in a drier airmass which will help
ceilings lift and scatter out by 18Z Monday.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
345 PM EDT SUN MAY 10 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND LIFT NORTHEAST OVER THE COASTAL
PLAIN TONIGHT INTO MONDAY. A COLD FRONT APPROACHES FROM THE
NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL
THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 345 PM SUN...REMNANTS OF ANA CURRENTLY OVER SE NC...AND
SLOWLY LIFTING NORTH NORTHEAST. HEAVY RAINS HAVE ABATED FOR THE
TIME BEING...WITH BULK OF RAIN SHOWERS MORE STRATIFORM AND
CONCENTRATED NEAR THE STORM CENTER. THINKING THAT CONVECTIVE BANDS
OF RAIN SHOWERS WITH EMBEDDED THUNDER...HEAVY AT TIMES...WILL
REDEVOLOP OVERNIGHT PER MESOSCALE CONVECTIVE INITIATING MODELS.
WILL LEAVE FLOOD WATCH INTACT. ALSO...ISOLATED TOR THREAT MAY
DEVELOP AS FAVORABLE LOW LEVEL SHEAR VALS INC OVERNIGHT AS CENTER
OF ANA MAKES HER WAY THROUGH THE COASTAL PLAIN/INTERSTATE 95
CORRIDOR. HIGH RES MODELS INDICATE AN UPTICK IN UPDRAFT HELICITY
AFTER AROUND 04Z...AND WITH SFC WINDS STILL BACKED SSE...THIS
WOULD YIELD INC LOW LEVEL HELICITY AS H85MB WINDS VEER SWRLY. WILL
CONTINUE TO HIGHLIGHT THESE THREATS IN HWO. MUGGY OVERNIGHT LOWS
WITH MOST AREAS DROPPING NOW LOWER THAN 70 OVERNIGHT.
&&
.SHORT TERM /MONDAY/...
AS OF 345 PM SUN...SHOULD SEE THREAT FOR HEAVY RAIN SHOWERS END
THROUGH THE EARLY MORNING WITH PRECIP COVERAGE AND INTENSITY
TAPERING OFF SOMEWHAT AS REMNANTS OF THE SYSTEM WITH BEST LIFT
MOVE NORTHEAST INTO VA. STILL HUNG ONTO LIKELY POPS ACROSS THE
NORTH WITH HIGH CHANCE/SCT SOUTHERN AREAS. TEMPS WILL BE HELD DOWN
AGAIN WITH THE MOSTLY CLOUDY SKIES...THOUGH SOME SUN COULD BREAK
OUT ESP IN THE AFTERNOON WITH READINGS IN THE 80S ACROSS THE SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
REMNANT ANA LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT.
HOWEVER A MOIST SW FLOW WILL REMAIN IN PLACE TUESDAY AHEAD OF
SHEARING UPPER TROF AND ASSOCD SFC COLD FRONT WITH CHANCES FOR
SCATTERED SHOWERS CONTINUING. MOIST BNDRY LAYER SUGGESTS MOCLOUDY
SKIES THRU TUESDAY MORNING THEN SUNNY BREAKS DEVELOP WITH MIXING
ALLOWING TEMPS TO SOAR TO NEAR 90 DEGREES INLAND TUESDAY AFTERNOON.
DESTABILIZATION AND SPEED SHEAR MAY BE SUPPORTIVE OF STRONG TO
SEVERE TSTORMS TUESDAY AFTERNOON INTO EVENING.
COLD FRONT SLIDES THRU THE AREA LATE TUESDAY NIGHT THEN UPPER RIDGE
BUILDS EAST WITH SFC HIGH RIDGING IN FROM THE NORTH. THE DRIER, MORE
STABLE AIRMASS WILL KEEP RAIN CHANCES AT BAY THRU AT LEAST THURSDAY
AND POSSIBLY THRU THE END OF THE WEEK UNLESS SHORT WAVE ENERGY/DEEP
MOISTURE CAN PENETRATE UPPER RIDGE MOVING OFFSHORE.
MAY BE INCREASINGLY UNSETTLED NEXT WEEKEND AS ZONAL FLOW AND STALLED
SFC BNDRY LINGER OVER THE AREA.
AFTER A HOT/HUMID TUESDAY, TEMPERATURES WILL SETTLE TO SLIGHTLY BLO
NORMAL LEVELS THRU THE END OF THE WEEK. TEMPS MAY REBOUND TO MORE
SEASONAL LEVELS NEXT WEEKEND DEPENDING ON PLACEMENT OF STALLED OUT
SFC FRONT.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AS OF 130 PM SUN...VFR/MVFR CONDITIONS OVER EASTERN NORTH
CAROLINA TAFS AS CENTER OF ANA MOVES NORTH INTO NC TO OUR SW.
RAIN BANDS ROTATING ACROSS REGION FROM OFFSHORE EXTENDS FROM
ONSLOW/CARTERET COUNTY TO THE NW AS IT CONTINUES TO PUSH TO THE
NORTH AND AFFECTING KEWN AND KPGV REDUCING CIGS TO MVFR. EXPECT TO
SEE MORE STEADY RAIN STARTING IN LATER THIS AFTERNOON AS CENTER OF
ANA MOVES SLOWLY NORTH. HAVE MODERATE CONFIDENCE IN MVFR
CONDITIONS ACROSS ALL TERMINALS WITH ISOLATED IFR CONDITIONS.
WINDS HAVE NOT BEEN AN ISSUE WITH GUSTS LIMITED TO STRONGER BANDS
MOVING ACROSS THE TERMINALS MIXING STRONGER WINDS ALOFT DOWN
BRIEFLY. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON BANDED
PRECIPITATION MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF
BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS ANA
TRANSITIONS TO MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED
PRECIPITATION WILL BECOME MORE STARTIFORM WITH LOWER CEILINGS. AS
ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING
AFTER 12Z.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANA REMNANT LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT,
HOWEVER RESIDUAL LOW LEVEL MOISTURE AND SCATTERED PRECIPITATION MAY
SUPPORT SUB-VFR CONDITIONS THRU TUESDAY MORNING. MIXING WILL SCATTER
OUT CLOUD COVER BY MIDDAY TUESDAY THEN SCATTERED SHOWER AND
THUNDERSTORMS (SOME OF WHICH CUD BE STRONG/SEVERE) AFFECT THE AREA
TUESDAY AFTERNOON AND EVENING. DRYING AIRMASS BUILDS IN AFTER A COLD
FRONT PASSAGE LATE TUESDAY NIGHT WITH PREDOMINATE VFR EXPECTED
THEREAFTER.
&&
.MARINE...
AS OF 345 PM SUNDAY...GUSTY S TO SE WINDS THIS AFTERNOON MAINLY
20 TO 25 KT SOUTHERN WATERS WITH LIGHTER WINDS NORTHERN WATERS
AROUND 10 TO 15 KTS. SEAS IN THE 7-9 FOOT RANGE SOUTHERN WATERS
TO 3 TO 5 FEET NORTHERN WATERS. THE REMNANTS OF ANA WILL LIFT
NORTHEAST ACROSS THE COASTAL PLAIN OVERNIGHT WITH WINDS BECOMING
SOUTHERLY AND INC ACROSS ALL WATERS AND THE PAMLICO SOUND. CURRENT
SCA LOOKS IN GOOD SHAPE.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
DESPITE DEPARTING ANA, MARINE WEATHER REMAINS ACTIVE THRU MUCH OF
THIS WEEK. MODERATE TO STRONG SW WINDS AND LINGERING SEAS WILL KEEP
SMALL CRAFT ADVISORIES LIKELY THRU TUESDAY NIGHT AHEAD OF A COLD
FRONT PASSAGE LATE TUESDAY NIGHT OR EARLY WEDNESDAY. MAY BE A LULL
IN SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY BEFORE STRONGER POST
FRONTAL N/NE WINDS KICK UP AGAIN WED NIGHT INTO THURSDAY. WINDS/SEAS
GRADUALLY RELAX THU NIGHT FRIDAY AS PRESSURE GRADIENT DECREASES AT
THE COAST WITH HIGH BUILDING IN FROM THE NORTH.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS OCCASIONAL BANDS OF
HEAVY SHOWERS PIVOT ACROSS E NC THROUGH LATE TONIGHT. THE HEAVIER
SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. HEAVIEST
RAIN THREAT LOOKS TO OCCUR OVERNIGHT TONIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH MONDAY MORNING FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...BTC
MARINE...BTC/TL
HYDROLOGY...TL/RF
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
142 PM EDT SUN MAY 10 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND MOVE NORTHWEST OVER NORTHERN SOUTH
CAROLINA TODAY...THEN LIFT NORTHEAST INLAND FROM THE COAST
TONIGHT AND MONDAY. A COLD FRONT APPROACHES FROM THE NORTHWEST
TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL THEN
BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1145 AM SUN...UPDATED FCST TO EXPIRE TROPICAL STORM
WARNING. GUSTY SOUTH TO SE WINDS WILL CONTINUE ESP NEAR THE COAST
THOUGH BIGGESET CONCERN WILL BE HEAVY RAIN THREAT TODAY. CONTINUED
CATEGORICAL POPS WESTERN HALF OF FA WITH HIGH LIKELY TO SCT ACROSS
THE FAR EAST. COULD SEE POCKETS OF SUNSHINE BREAK OUT BY THIS
AFTERNOON AND THIS WOULD EXACERBATE THE HEAVY RAIN THREAT AS ANY
INC IN INSTABILITY WILL AID IN CONVECTIVE SHOWER/TS COVERAGE
LATER. PWATS APPROACHING 2 INCHES WHICH IS ABOVE THE MAX FOR EARLY
TO MID MAY.
PREV DISC...AS OF 725 AM SUNDAY...ISSUED FLOOD WATCH FOR SW TIER.
RADAR AND SATL SHOW GOOD BANDING OF SHRA/ISOLD TSRA DEVELOPING E
OF ANA AND THIS LOOKS TO TRAIN OVER SRN TIER. WITH PRECIP WTR
VALUES APPROACHING 2 INCHES VERY HEAVY DOWNPOURS GOOD BET WITH
POTENTIAL FOR SOME TRAINING AND POSSIBLE FOOD CONCERNS.
PREV DISC...TROPICAL STORM ANA IS MOVING ASHORE NEAR MYRTLE BEACH
EARLY THIS MORN. BANDS OF SHRA CONT TO ROTATE NW ACROSS THE SW
HALF OF REGION AND THAT TREND SHLD CONT THRU THE MORN AS ANA
SLOWLY MOVES NNW. LATER TODAY ANA WILL BEGIN TO TURN N BUT REMAIN
SW OF ERN NC. WITH HEATING EXPECT CVRG OF SHRA/ISOLATED TSRA TO
GRAD INCREASE ACROSS AREA...CONT TO HAVE POPS RANGING FROM
CATEGORICAL OVER SRN SECTION TO CHC NE. LOCALLY HEAVY RAIN LIKELY
WITH PRECIP WTR VALUES REACHING NEAR 2 INCHES SRN TIER. SO FAR
HAVE NOT SEEN ANY SIGN OF ORGANIZED ROTATION IN ANY OF THE CELLS
OR BANDS OF SHRA/ISOLD TSRA. LATER TODAY WITH SOME HEATING MAY SEE
SLIGHTLY BETTER CHC OF TORNADO AS AREA BEGINS TO GET IN RIGHT
FLANK OF THE CIRC...ESPCLY S. HIGH IN THE UPR 70S TO LOWER
80S...GUSTY SE WINDS SRN AREAS CLOSER TO TS ANA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 225 AM SUNDAY...ANA WILL GRAD WEAKEN BUT SHLD SEE WELL
DEFINED CIRC MOVE NNE NEAR OR JUST E OF I95 OVERNIGHT. EXPECT
NUMEROUS SHRA/ISOLATED TSRA TO CONT WITH LOCALLY HEAVY RAIN A GOOD
BET AS TROP MOISTURE STREAMS N OVER ERN NC. TORNADO CHCS WILL
INCREASE OVERNIGHT AS ERN NC WILL BE IN MOST FAVORABLE RIGHT FLANK
OF THE CIRC...INSTAB IS WEAK AND THIS MAY LIMIT THREAT SOMEWHAT
BUT CERTAINLY THERE WILL BE A CHC OF A TORNADO OR TWO WITH
FAVORABLE SHEAR OVER THE REGION. GUSTY MAINLY SE TO S WINDS
EXPECTED ESPCLY COAST WITH MILD LOWS IN THE UPR 60S TO LOWER 70S.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
AS OF 329 AM SUN...REMNANTS OF TROPICAL STORM ANA WILL BE PUSHING
TOWARD THE NORTHEAST DURING THE DAY ON MONDAY. PRECIPITABLE WATERS
AROUND TWO INCHES COMBINED WITH ELEVATED CAPE AND GOOD DIRECTIONAL
/SPEED SHEAR WILL LEAD TO AN ACTIVE DAY WITH FLOODING AND ISOLATED
TORNADOES POSSIBLE.
UPPER TROUGH OVER THE CENTRAL PART OF THE COUNTRY WILL DRAG A COLD
FRONT TO NORTH CAROLINA ON TUESDAY. SOUTH SOUTHWESTERLY FLOW AHEAD
OF THE APPROACHING FRONT WILL CONTINUE THE CHANCE OF THUNDERSTORM
ACTIVITY ON TUESDAY WITH HIGH TEMPERATURES IN THE UPPER 80S. FRONT
EXPECTED TO EXIT OFF THE COAST ON WEDNESDAY MORNING WITH
PRECIPITATION CHANCES ENDING.
HIGH PRESSURE WILL BUILD OVER THE AREA WITH HIGH TEMPERATURES
DROPPING A COUPLE OF CATEGORIES INTO THE UPPER 70S TO LOWER 80S
THROUGH THE REMAINDER OF THE WORK WEEK. MODELS HINTING AT A WEAK
FRONT MOVING THROUGH NORTH CAROLINA OVER THE WEEKEND WITH A SMALL
CHANCE OF RAIN ASSOCIATED WITH IT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 130 PM SUN...VFR/MVFR CONDITIONS OVER EASTERN NORTH
CAROLINA TAFS AS CENTER OF ANA MOVES NORTH INTO NC TO OUR SW.
RAIN BANDS ROTATING ACROSS REGION FROM OFFSHORE EXTENDS FROM
ONSLOW/CARTERET COUNTY TO THE NW AS IT CONTINUES TO PUSH TO THE
NORTH AND AFFECTING KEWN AND KPGV REDUCING CIGS TO MVFR. EXPECT TO
SEE MORE STEADY RAIN STARTING IN LATER THIS AFTERNOON AS CENTER OF
ANA MOVES SLOWLY NORTH. HAVE MODERATE CONFIDENCE IN MVFR
CONDITIONS ACROSS ALL TERMINALS WITH ISOLATED IFR CONDITIONS.
WINDS HAVE NOT BEEN AN ISSUE WITH GUSTS LIMITED TO STRONGER BANDS
MOVING ACROSS THE TERMINALS MIXING STRONGER WINDS ALOFT DOWN
BRIEFLY. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON BANDED
PRECIPITATION MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF
BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS ANA
TRANSITIONS TO MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED
PRECIPITATION WILL BECOME MORE STARTIFORM WITH LOWER CEILINGS. AS
ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING
AFTER 12Z.
LONG TERM /MON THROUGH THURSDAY/...
AS OF 346 AM SUN...REMNANTS OF ANA WILL BE MOVING THROUGH THE
EASTERN NORTH CAROLINA TAF SITES ON MONDAY WITH WIDSPREAD SUB VFR
CONDITIONS EXPECTED THROUGH THE DAY. RAIN...GUSTY WINDS...AND
SEVERE WEATHER WITH TORNADOES A POSSIBILITY. LLWS AND CROSS WIND
ALSO EXPECTED.
ANA WILL EXIT THE AREA MONDAY NIGHT WITH IMPROVING CONDITIONS. A
FRONT WILL APPROACH THE AREA WITH SUBVFR CONDITIONS POSSIBLE TUESDAY
AND TUESDAY EVENING AHEAD OF THE FRONT IN RAIN AND LOW CLOUDS. VFR
CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE FORECAST PERIODS
WITH HIGH PRESSURE OVER THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1145 AM SUNDAY...UPDATED TO EXPIRE TS WARNING FOR THE
SOUTHERN WATERS. GUSTY S TO SE WINDS TODAY MAINLY 20 TO 30 KT WITH
LIGHTER WINDS NORTHERN WATERS AROUND 10 TO 15 KTS. SEAS WILL BE 8
TO 10 FEET SOUTHERN WATERS TO AND SEAS 3 TO 5 FT OVR NRN WTRS.
THE STRONG ONSHORE FLOW WILL KEEP SURF ROUGH OVER BEACHES FROM HAT
S. ANA OR ITS REMNANTS WILL LIFT NNE TONIGHT INLAND FROM THE
COAST. WINDS WILL DIMINISH A BIT SRN TIER AS ANA WEAKENS...HOWEVER
SPEEDS SHLD INCREASE ACROSS CNTRL AND NRN TIER TO THE E OF THE
CIRC...HAVE STARTED SCA FOR PAMLICO SOUND AND NRN CSTL WTRS LATER
THIS EVENING. SEAS WILL SUBSIDE TO 7 TO 9 FEET S OVERNIGHT AND
BUILD TO 5 TO 7 FEET FAR N.
LONG TERM /MON THROUGH THURSDAY/...
AS OF 350 AM SUN...SMALL CRAFT ADVISORY CONDITIONS EXPECTED MONDAY
AS REMNANTS OF TROPICAL STORM ANA MOVE NORTH THROUGH NORTH CAROLINA.
DEPENDING ON HOW DEEP THE LOW GETS...MAY SEE GALE CONDITIONS
REALIZED DURING THE DAY. SEAS EXPECTED TO BE 8 TO 10 FEET.
CONDITIONS MAY BRIEFLY DROP BELOW SMALL CRAFT ADVISORY CRITERIA
TUESDAY MORNING. HOWEVER AN APPROACHING COLD FRONT WILL TIGHTEN THE
GRADIENT AGAIN FOR SMALL CRAFT POSSIBLE BY LATE TUESDAY. FRONT WILL
MOVE THROUGH THE WATERS WEDNESDAY WITH HIGH PRESSURE BUILDING IN
THROUGH THE REMAINDER OF THE FORECAST PERIOD.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS BANDS OF HEAVY SHOWERS
PIVOT ACROSS E NC THROUGH TONIGHT. THE HEAVIER SHOWERS WILL
PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. WILL HAVE TO MONITOR
FOR POTENTIAL EXPANSION OF THE FLOOD WATCH FURTHER EAST LATER ON
ACCORDING TO RADAR TRENDS AND MOVEMENT OF REMNANTS OF ANA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH MONDAY MORNING FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF/TL
SHORT TERM...RF
LONG TERM...CCG
AVIATION...CCG/MAC
MARINE...CCG/RF/TL HYDROLOGY...
AREA FORECAST DISCUSSION
NWS MEDFORD OR
226 PM PDT SUN MAY 10 2015
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS CUMULUS ALREADY STARTING
TO BUILD UP ALONG THE CASCADES AND FROM THE SCOTT VALLEY TO THE
TRINITY ALPS AND AND SISKIYOUS IN NORTHERN CAL AND ARE MOVING
NORTHEAST. THE PAST SEVERAL RUNS OF THE HRRR MODEL (WHICH IS UPDATED
HOURLY) CONTINUES TO SHOW SOME CONVECTIVE SHOWERS IN THE ABOVE
MENTION AREAS IN ADDITION TO SOUTH THROUGH EASTERN JACKSON COUNTY
AND NORTHERN KLAMATH COUNTY. THE MODELS SUGGEST THERE`S ENOUGH
INSTABILITY FOR ISOLATED THUNDERSTORMS LATE THIS AFTERNOON INTO THIS
EVENING. THE 700 MB WINDS ARE FROM THE SOUTHWEST, SO SHOWERS AND
ISOLATED STORMS THAT DEVELOP WILL GENERALLY MOVE NORTHEAST. ISOLATED
STORMS WILL END THIS EVENING AS WE LOSE DAYTIME HEATING, BUT
INSTABILITY SHOWERS WILL CONTINUE OVERNIGHT AS THE UPPER TROUGH
CURRENTLY NEAR 45N/130W DIGS SOUTH TOWARDS THE OREGON COAST.
THE UPPER TROUGH WILL EVOLVE INTO AN UPPER LOW AND THIS WILL BE
RESPONSIBLE FOR BRINGING MUCH COOLER TEMPERATURES...SCATTERED
SHOWERS JUST ABOUT ANYWHERE IN THE FORECAST AREA MONDAY AND TUESDAY.
IN ADDITION, ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF
THE CASCADES BOTH MONDAY AND TUESDAY AFTERNOON AND EARLY EVENING.
THE UPPER TROUGH WILL DIG SOUTH AND BECOME AND UPPER LOW MONDAY...
REACH THE OREGON COAST MONDAY AFTERNOON, THEN MOVE OVER THE AREA
MONDAY NIGHT INTO TUESDAY. THE MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE PLACEMENT OF THE UPPER LOW WHICH YIELDS HIGHER CONFIDENCE
WE`LL BE COOL AND WET FOR THE START OF NEXT WEEK. THE MODELS ALSO
SHOW THE GREATEST INSTABILITY ALONG AND EAST OF THE CASCADES AND
PLENTY OF SHORTWAVES WILL MOVE OUT AHEAD OF THE UPPER LOW MONDAY
PROVIDING THE TRIGGER FOR ISOLATED STORMS TO FIRE UP.
THE UPPER LOW WILL MOVE OVERHEAD ON TUESDAY BRINGING COLD AIR ALOFT
WITH 500 MB TEMPERATURES BETWEEN -25 AND -28C. SHOWERS WILL OCCUR
JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN THE
AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE EXPECTED
TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN HEAVIER
SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE OVER THE
HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. ISOLATED
THUNDERSTORMS REMAIN A CONCERN TUESDAY AFTERNOON ALONG AND EAST OF
THE CASCADES.
SHOWERS ARE EXPECTED TO GRADUALLY DECREASE TUESDAY NIGHT AS THE
UPPER LOW WEAKENS AND MOVES NORTH. HOWEVER THE NAM SHOW ANOTHER
SHORTWAVE ON THE HEALS OF THE UPPER TROUGH AND WE COULD SEE SHOWERS
INCREASE AGAIN EARLY WEDNESDAY MORNING. THE GFS IS SLOWER WITH THE
NEXT SHORTWAVE AND EC IS ALSO SLOWER AND WEAKER. EITHER ONE OF THESE
SOLUTIONS WILL RESULT IN A COOL AND UNSETTLED PATTERN ON WEDNESDAY.
-PETRUCELLI
&&
.AVIATION...FOR THE 10/18Z TAF CYCLE...A LOW PRESSURE SYSTEM
WILL BRING SOME ISOLATED THUNDERSTORMS AND SHOWERS OVER INLAND AREAS
THROUGH THIS EVENING...THEN EXPECT SHOWERS TO MOVE INLAND OVER THE
AREA TONIGHT AND MONDAY MORNING ALONG THE COAST...VFR CONDITIONS
WILL CONTINUE THIS AFTERNOON...THEN MVFR CIGS ARE EXPECTED TO
DEVELOP AROUND 00Z AND PERSIST THROUGH THE EVENING. OVERNIGHT
THROUGH MONDAY MORNING...EXPECT A MIX OF VFR/MVFR CIGS ALONG THE
COAST. INLAND...VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING.
HOWEVER ISOLATED THUNDERSTORMS ARE EXPECTED ALONG FROM THE SISKIYOUS
AND WESTERN SLOPES OF THE CASCADES AND EASTWARD LATE THIS AFTERNOON
AND THIS EVENING. THIS MAY BRING SOME ISOLATED MVFR CIGS TO THESE
AREAS ALONG WITH VARIABLE AND GUSTY WINDS. THEN AS SHOWERS MOVE
INLAND OVERNIGHT, EXPECT WIDESPREAD MVFR CIGS LATE THIS EVENING INTO
TONIGHT...CONTINUING INTO MONDAY MORNING. WIDESPREAD MOUNTAIN
OBSCURATIONS ARE ALSO EXPECTED LATE THIS EVENING THROUGH MONDAY
MORNING. /CC
&&
.MARINE...UPDATED 145 PM PDT SUNDAY, MAY 10, 2015...A DRY COLD FRONT
MOVING THROUGH THE WATERS THIS AFTERNOON WILL CAUSE NORTH WINDS TO
INCREASE THROUGH EARLY MONDAY. THESE INCREASING NORTH WINDS WILL
RESULT IN STEEP SEAS FOR MOST OF THE WATERS BEYOND 10 MILES OF THE
COAST AND INNER WATERS SOUTH OF PORT ORFORD. THESE SMALL CRAFT
ADVISORY CONDITIONS ARE EXPECTED TO LINGER THROUGH MONDAY NIGHT.
SHOWERS ARE EXPECTED MONDAY EVENING THROUGH WEDNESDAY. WINDS AND
SEAS WILL DIMINISH ON TUESDAY AND ARE LIKELY REMAIN BELOW ADVISORY
LEVELS THROUGH THURSDAY. -SCHAAF
.FIRE WEATHER...UPDATED 100 PM PDT SUNDAY, MAY 10, 2015...A WEAK
COLD FRONT WILL PERSIST OVER THE AREA THIS AFTERNOON AND EVENING
ALLOWING SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP FROM ABOUT
THE SHASTA AND SCOTT VALLEYS NORTHWARD TO THE SISKIYOUS AND INTO THE
CASCADES THIS AFTERNOON. STORMS ARE ALSO POSSIBLE ALONG THE WESTERN
SLOPES OF THE CASCADES AND INTO PORTIONS OF THE ROGUE VALLEY LATE
THIS AFTERNOON. THEN THIS EVENING...EXPECT ISOLATED THUNDERSTORMS
FROM THE CASCADES EASTWARD. MID-LEVEL SOUTHWEST FLOW WITH NORTHWEST
FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND MOISTURE TO CONVERGE
IN THESE AREAS AND MODELS CONTINUE TO SHOW INSTABILITY WITH THE
POTENTIAL FOR ISOLATED THUNDERSTORMS. STORMS SHOULD GENERALLY
PRODUCE RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE
AT 0.10" TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM
SOUTHWEST TO NORTHEAST AT 10-20 KNOTS. THE STORMS WILL CAPABLE OF
GUSTY OUTFLOW WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY WEST TO
SOUTHWEST WINDS ARE EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE
THIS AFTERNOON, WITH GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST
SIDE.
SCATTERED SHOWERS ACROSS THE AREA TONIGHT WILL INCREASE IN COVERAGE
AND INTENSITY MONDAY MORNING THROUGH MONDAY EVENING AS AN UPPER LOW
MOVES INTO THE COAST. ISOLATED THUNDERSTORMS MIXED WITH SHOWERS
ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND EVENING,
PRIMARILY FOR EASTERN SISKIYOU, MODOC, EASTERN KLAMATH AND LAKE
COUNTIES. THEN SHOWERS AND ISOLATED THUNDERSTORMS ARE LIKELY OVER
MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW MOVES OVERHEAD.
/CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
TO 11 PM PDT MONDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR
PZZ376.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
921 AM PDT SUN MAY 10 2015
.DISCUSSION...MADE A FEW ADJUSTMENTS TO THE FORECAST FOR TODAY.
CURRENT VISIBLE IMAGE SHOWS A CIRRUS SHIELD MOVING OVER THE
REGION THIS MORNING WHICH WILL INITIALLY LIMIT THE AMOUNT OF
SURFACE HEATING, BUT THIS WILL MOVE EAST LATE THIS MORNING. WHAT
MAY HAPPEN IS ISOLATED STORMS WILL BE DELAYED UNTIL LATE THIS
AFTERNOON. THE CIRRUS SHIELD IS THINNER IN SISKIYOU COUNTY, SO IT
WILL HAVE LITTLE OR NO EFFECT ON SURFACE HEATING THERE AND
ISOLATED STORMS COULD DEVELOP THERE EARLY THIS AFTERNOON. ALSO THE
LATEST HRRR MODEL SHOWS CONVECTIVE SHOWERS BREAKING OUT FURTHER
WEST INTO PARTS OF JACKSON COUNTY LATE THIS AFTERNOON AND HAVE
EXPANDED THE MENTION OF ISOLATED THUNDER. THE FLOW AT 700 MB WILL
BE FROM THE SOUTHWEST, SO SHOWERS AND ISOLATED STORMS THAT DEVELOP
WILL MOVE NORTHEAST.
IN ADDITION SHOWERS AND ISOLATED STORMS THAT DEVELOP ALONG THE
CASCADES WILL TEND TO MOVE NORTHEAST INTO NORTHERN KLAMATH COUNTY
AND HAVE EXPANDED THE COVERAGE TO INCLUDE THIS AREA.
KEEP IN MIND, MOST HOURS AND LOCATIONS WILL HAVE CONVECTIVE
SHOWERS, BUT CONDITIONS ARE FAVORABLE FOR ISOLATED THUNDERSTORMS
LATE THIS AFTERNOON AND EVENING. -PETRUCELLI
&&
.AVIATION...IFR AND MVFR CIGS WILL GRADUALLY LIFT TO VFR LATE THIS
MORNING AND WILL CONTINUE INTO THIS AFTERNOON. THE MAIN CONCERN
WILL BE THE POTENTIAL FOR ISOLATED THUNDERSTORMS FROM ABOUT THE
SCOTT VALLEY, SISKIYOUS, AND CASCADES THIS AFTERNOON, SPREADING
NORTHEASTWARD ACROSS THE EAST SIDE DURING THE EVENING. THESE
STORMS WILL BE CAPABLE OF GUSTY OUTFLOW WINDS, ESPECIALLY THIS
AFTERNOON, AS WELL AS BRIEF MVFR TO IFR DOWNPOURS AND SMALL HAIL.
AREAS AROUND KMFR COULD BE AFFECTED BY THUNDERSTORMS BETWEEN 00Z
AND 03Z. THIS EVENING AND OVERNIGHT MVFR AND SHOWERS ARE EXPECTED
ACROSS THE INTERIOR WEST SIDE. -PETRUCELLI
&&
.MARINE...UPDATED 230 AM PDT SUNDAY, MAY 10, 2015...A MOSTLY DRY
COLD FRONT MOVING THROUGH THIS AFTERNOON WILL CAUSE NORTH WINDS TO
INCREASE THROUGH EARLY MONDAY. THESE INCREASING NORTH WINDS WILL
RESULT IN SMALL CRAFT ADVISORY CONDITIONS FOR MUCH OF THE AREA SOUTH
AND WEST OF CAPE BLANCO TONIGHT THROUGH MONDAY NIGHT...PRIMARILY FOR
STEEP SEAS. SHOWERS ARE EXPECTED LATE MONDAY NIGHT THROUGH
WEDNESDAY. WINDS AND SEAS WILL DIMINISH ON TUESDAY AND ARE LIKELY
REMAIN BELOW ADVISORY LEVELS THROUGH THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 640 AM PDT SUN MAY 10 2015/
DISCUSSION...A COLD FRONT IS ON TRACK TO MOVE ASHORE THIS MORNING
AND CROSSES THE CASCADES INTO THE KLAMATH BASIN BY EARLY THIS
AFTERNOON. HIGHS TODAY WILL BE ABOUT 5 DEGREES COOLER WEST OF THE
CASCADES...WHILE TEMPERATURES EAST OF THE CASCADES ARE NOT
EXPECTED TO BE MUCH DIFFERENT THAN YESTERDAY. MODELS SUGGEST
ENOUGH INSTABILITY EXIST TO WARRANT A SLIGHT CHANCE OF
THUNDERSTORMS ALONG THE CASCADES AND FROM ABOUT THE SCOTT VALLEY
TO THE TRINITY ALPS AND SISKIYOUS IN NORTHERN CAL. PRECIPITABLE
WATER WILL ALSO BE INCREASING AND COMING UP FROM THE SACRAMENTO
VALLEY INTO THE SHASTA VALLEY. IT`S POSSIBLE THAT ANY STORM THAT
DEVELOP WILL PRODUCE RAINFALL. THE AREA OF INSTABILITY WILL
CONTINUE TO SHIFT EAST THIS EVENING WITH THUNDERSTORM POTENTIAL
EXPANDING INTO THE WARNER MOUNTAINS.
THE UPPER LEVEL TROUGH WILL DIG SOUTH WITH THE CLOSED LOW COMING
INLAND NEAR REEDSPORT MONDAY AFTERNOON. THE LOW PRESSURE IS
EXPECTED TO MOVE OVER THE SOUTHERN OREGON MONDAY NIGHT INTO
TUESDAY PER THE GFS SOLUTION, WITH THE ECMWF KEEPING THE LOW
OVER THE GOOSE LAKE AREA. IN BOTH SOLUTIONS THERE IS PLENTY OF
COLD AIR ALOFT THAT WILL HELP TO DESTABILIZE THE ATMOSPHERE. THIS
IN COMBINATION WITH DAYTIME HEATING WILL RESULT IN MORE
WIDESPREAD SHOWERS. THE MODELS SHOW THE GREATEST INSTABILITY ALONG
AND EAST OF THE CASCADES WITH DIVERGENCE ALOFT, SO HAVE MODERATE
CONFIDENCE FOR THUNDERSTORMS IN THIS AREA, ESPECIALLY GIVEN THAT
500MB TEMPERATURES WILL BE BETWEEN -25 AND -28C. SHOWERS WILL
OCCUR JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN
THE AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE
EXPECTED TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN
HEAVIER SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE
OVER THE HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. MEANWHILE
THERE`S STILL A CHANCE FOR THUNDERSTORMS ALONG AND EAST OF THE
CASCADES. SHOWERS WILL GRADUALLY DECREASE TUESDAY NIGHT AS THE
UPPER LOW MOVES AWAY AS WE LOSE DAYTIME HEATING. /FB
FIRE WEATHER...UPDATED 600 AM PDT SUNDAY, MAY 10, 2015...A COLD
FRONT WILL DEVELOP OVER THE AREA TODAY GIVING RISE TO SHOWERS AND
ISOLATED THUNDERSTORMS FROM ABOUT THE SCOTT VALLEY, SISKIYOUS, AND
CASCADES EASTWARD. THE BEST POSSIBILITY FOR THUNDERSTORMS TODAY
APPEARS TO BE FROM ABOUT THE NORTHEASTERN TRINITY ALPS AND THE
EASTERN SCOTT AND SHASTA VALLEYS NORTH-NORTHEASTWARD INTO AREAS OF
KLAMATH COUNTY FROM THE CASCADE CREST EASTWARD. MID-LEVEL SOUTHWEST
FLOW WITH NORTHWEST FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND
MOISTURE TO CONVERGE IN THESE AREAS, WHERE PRECIPITABLE WATER VALUES
OF 0.50" TO 0.75" ARE EXPECTED AND MODEL LIFTED INDICES AREA MOSTLY
IN THE -2C TO -4C RANGE. THIS MEANS STORMS SHOULD GENERALLY PRODUCE
RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE AT 0.10"
TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM SOUTHWEST TO
NORTHEAST AT 15-20 KNOTS. THE STORMS WILL CAPABLE OF GUSTY OUTFLOW
WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY SOUTHWEST WINDS ARE
EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE THIS AFTERNOON, WITH
GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST SIDE. SCATTERED SHOWERS
ACROSS THE AREA TONIGHT WILL INCREASE IN COVERAGE AND INTENSITY
MONDAY AFTERNOON AND EVENING UNDER A GENERAL WEST FLOW. ISOLATED
THUNDERSTORMS ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND
EVENING, PRIMARILY EAST OF THE CASCADES. SHOWERS AND THUNDERSTORMS
ARE LIKELY OVER MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW
MOVES OVERHEAD. BTL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
TO 11 PM PDT MONDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR
PZZ376.
$$
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1246 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1235 PM CDT SUN MAY 10 2015
ADJUSTMENTS TO POPS/TSTM COVERAGE WERE MADE TO ACCOUNT FOR
CURRENT STORMS MOVING NORTH OVER WESTERN PART OF AREA AND EXPECTED
BIG INCREASE SHORTLY FURTHER EAST...OF COURSE CURRENT TORNADO
WATCH IS GOOD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE
LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO
OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC
LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO
CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST
LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO
THE AREA BY MID TO LATE MORNING.
MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED
SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE
AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW
MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE
MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT
SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z.
TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL
INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG
RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK
SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING
VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE
RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE
LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z
WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER
AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND
EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS
THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND
DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE
RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1
EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED
TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z.
SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST
THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL
BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY
QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL
BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE
UPPER 30S TO MID 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY
ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND
COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY
STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS
THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER
ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL
ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD
REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE
MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY
SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S.
LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY
BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY
WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE
MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH
SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS
THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE
MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE
WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER
CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE
STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS
HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN
TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING
GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE
70S BY LATE IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1235 PM CDT SUN MAY 10 2015
GENERALLY IFR CEILINGS AND AREAS OF VISIBILITY 3-5SM SHRA/TSRA FAR
WESTERN PART OF THE FORECAST AREA INCLUDING KHON...AFT 11/00Z THIS
AREA WILL SEE CEILINGS 1-2K FEET VARIABLE TO BELOW 1K FEET WITH
SCATTERED -SHRA. OVER CENTRAL AND EASTERN PART OF THE AREA
CEILINGS 1-3K FEET WITH SOME CEILINGS BELOW 1K FEET ESPECIALLY
NORTH OF KFSD. AREAS OF VISIBILITY 3-5SM IN SHRA/TSRA...THEN AFTER
11/03Z CEILINGS 1-2K FEET VARIABLE TO BELOW 1K FEET...SCT -SHRA
MAINLY NORTH OF FSD. SURFACE GUSTS ABOVE 25 KNOTS FROM THE
SOUTHEAST OVER SOUTHEAST PART OF THE AREA...OTHERWISE SURFACE
GUSTS ABOVE 25 KNOTS FROM THE W/NW DEVELOPING FROM THE WEST AFTER
11/12Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...JM
LONG TERM...JH
AVIATION...
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1243 PM CDT SUN MAY 10 2015
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1101 AM CDT SUN MAY 10 2015/
DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND
PROFILES SHOW A MESOSCALE CONVECTIVE SYSTEM MOVING OVER WESTERN
ARKANSAS...NORTHEAST OKLAHOMA...AND NORTHEAST TEXAS LATE THIS
MORNING. REGIONAL WSR-88D RADAR TRENDS SHOW STORMS EXHIBITING
QUASI-LINEAR CHARACTERISTICS OVER WESTERN ARKANSAS. AS OF 10 AM
CDT ACROSS THE MID SOUTH...TEMPERATURES ARE IN THE 70S AT MOST
LOCATIONS WITH MOSTLY SUNNY SKIES PREVALENT ACROSS MUCH OF THE
AREA AS OF THIS MOMENT.
LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THE BEST CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE MAINLY WEST OF THE MISSISSIPPI
RIVER THIS AFTERNOON WHERE BETTER FORCING AND INSTABILITY MAY
RESIDE. FURTHER EAST...CONFIDENCE IS MUCH LOWER AND REDUCED RAIN
CHANCES NORTH OF I-40 ACROSS WEST TENNESSEE DOWN TO ISOLATED
COVERAGE. WILL UPDATE ALL ELEMENTS AS NEEDED TO ACCOUNT FOR THESE
TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 628 AM CDT SUN MAY 10 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION.
PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/
DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...18Z TAFS
A LINE OF STRONG TO SEVERE THUNDERSTORMS IN WEST ARKANSAS HAS BEEN
SLOWING ITS FORWARD PROGRESS AND WEAKENING SLIGHTLY OVER THE LAST
SEVERAL HOURS. SHORT TERM GUIDANCE SUGGESTS THIS TREND SHOULD
CONTINUE AND THE NORTHERN END OF THE LINE SHOULD BECOME THE FOCUS.
THAT SEEMS TO BE ALREADY HAPPENING. AS A RESULT...DO NOT FEEL LIKE
IT WILL POSE A THREAT TO ANY OF THE TAF SITES. JBR MAY BE THE
EXCEPTION AS STORMS PASS TO THE NORTH...BUT WILL ONLY INCLUDE VCTS
FOR NOW. BETTER RAIN AND THUNDER CHANCES WILL OCCUR LATER TONIGHT
AS ANOTHER LINE DEVELOPS AND APPROACHES FROM THE WEST.
SHOWERS MAY DEVELOP BEFORE THIS NEXT LINE OVER SOUTHERN ARKANSAS
AND NORTH MISSISSIPPI AND TRACK NORTH...BUT COVERAGE SHOULD REMAIN
LIMITED. VISIBLE SATELLITE DOES NOT SUGGEST ANY DEVELOPMENT IS
IMMINENT.
MVFR CIGS ARE EXPECTED BEFORE SUNRISE AT ALL SITES ALONG WITH MVFR
VIS DUE TO RAIN AT JBR MKL AND MEM...CONTINUING THROUGH 18Z. WINDS
SOUTHERLY AROUND 10KT WITH HIGHER GUSTS...SHIFTING SOUTHWESTERLY
LATE IN THE PERIOD.
30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1101 AM CDT SUN MAY 10 2015
.DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND
PROFILES SHOW A MESOSCALE CONVECTIVE SYSTEM MOVING OVER WESTERN
ARKANSAS...NORTHEAST OKLAHOMA...AND NORTHEAST TEXAS LATE THIS
MORNING. REGIONAL WSR-88D RADAR TRENDS SHOW STORMS EXHIBITING
QUASI-LINEAR CHARACTERISTICS OVER WESTERN ARKANSAS. AS OF 10 AM
CDT ACROSS THE MID SOUTH...TEMPERATURES ARE IN THE 70S AT MOST
LOCATIONS WITH MOSTLY SUNNY SKIES PREVALENT ACROSS MUCH OF THE
AREA AS OF THIS MOMENT.
LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THE BEST CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE MAINLY WEST OF THE MISSISSIPPI
RIVER THIS AFTERNOON WHERE BETTER FORCING AND INSTABILITY MAY
RESIDE. FURTHER EAST...CONFIDENCE IS MUCH LOWER AND REDUCED RAIN
CHANCES NORTH OF I-40 ACROSS WEST TENNESSEE DOWN TO ISOLATED
COVERAGE. WILL UPDATE ALL ELEMENTS AS NEEDED TO ACCOUNT FOR THESE
TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 628 AM CDT SUN MAY 10 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION.
PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/
DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...
12Z TAFS
UPPER LEVEL DISTURBANCES WILL BRING SEVERAL ROUNDS OF SHOWERS AND
STORMS TO JBR THROUGHOUT THE PERIOD...BUT MAINLY LATER FOR
MEM...MKL AND TUP. IN THE HEAVIEST STORMS EXPECT MVFR/IFR
CONDITIONS...OTHERWISE THE SITES WILL BE VFR. STRONGER SOUTH
WINDS ANTICIPATED WITH GUSTS NEAR 20 KTS AT JBR AND MEM. WINDS
WILL SUBSIDE SOME TONIGHT...BUT REMAIN GUSTY AT MEM AND JBR.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
400 PM CDT SUN MAY 10 2015
.DISCUSSION...
ALL EYES ARE UPON CENTRAL TEXAS WHERE SPC HAS MODERATE RISK OF
SEVERE STORMS AND THERE HAS ALREADY BEEN ONE TORNADIC STORM TO
PUSH THROUGH DENTON TX. SFC ANALYSIS OVER SE TX HAS TYPICAL WARM
SECTOR AIRMASS WITH GUSTY SE WINDS AND DEWPOINTS IN THE LOW 70S.
WATER VAPOR IMAGERY SHOWS UPPER LOW OVER C PLAINS WITH ELONGATED
TROUGH AXIS STRETCHING BACK INTO THE S ROCKIES AS EXPECTED
YESTERDAY. UPPER AIR ANALYSIS SHOWS JET STREAK COMING OUT OF
MEXICO WHICH LATEST RAP ANALYSES HAVE OVER S TX AND JUST STARTING
TO REACH SE TX. JET STREAK SHOULD MOVE OVER THE AREA BY 03Z
TONIGHT SO THINK ANY CAPPING MAY ERODED BY LARGE SCALE ASCENT.
LATEST HRRR RUNS HAS CONVECTION NOW OVER C TX FORMING A SQUALL
LINE AND PUSHING INTO THE BRAZOS VALLEY AFTER MIDNIGHT TO 3AM.
THIS EVOLUTION INTO SOME BOWING SEGMENTS SUPPORTS SPC
ENHANCED/SLIGHT RISK OF SEVERE FOR TONIGHT. GIVEN
SHEAR/INSTABILITY PARAMETERS FOR TONIGHT...THINK THIS KIND OF
CONVECTION WILL CERTAINLY BE POSSIBLE.
MONDAY LOOKS LIKE THERE WILL BE PLENTY OF RECOVERY IN THE AIRMASS
FOR IT TO DESTABILIZE WITH MODERATE TO HIGH CAPE BY THE AFTERNOON.
DEEP LAYER SHEAR SEEMS TO WEAKEN BUT LOW LEVEL WIND FIELDS LOOK
MUCH LESS THAN THE LAST COUPLE OF DAYS. A FRONTAL BOUNDARY DOES
PUSH INTO N TX WHICH MAY SLACKEN THE PRESSURE GRADIENT ACROSS THE
AREA. FRONT MAY BE THE FOCUS FOR SOME SEVERE STORMS WITH HEAVY
RAINFALL FOR NORTHERN PORTIONS OF THE AREA. TROUBLE PART OF THE
FORECAST IS THAT MODELS ARE NOT ALL THAT AGGRESSIVE WITH PRECIP
MONDAY DESPITE A MUCH WEAKER CAP AND FAVORABLE UPPER LEVEL
PARAMETERS. NOT ONLY THAT PRECIP WATER VALUES INCREASE TO AROUND
1.8 INCHES AND THEN OVERNIGHT AT 06Z TUE GFS SHOWS 2 INCH PRECIP
WATER VALUES. THIS IS JUST AS A SHORT WAVE TROUGH MOVES OVER THE
REGION. MODELS CONTINUE TO HIT HILL COUNTRY AND S TX TO THE
COASTAL PLAIN WITH QUITE A BIT OF PRECIP WHILE PRECIP TOTALS FOR
SE TX REMAIN SOMEWHAT LOW GIVEN THE SITUATION. ONE OF THE FEW
MODELS THAT DOES PRODUCE QUITE A BIT OF PRECIP OVER THE AREA IS
THE 12Z WRF-ARW WHICH BRINGS A SQUALL LINE INTO THE AREA FROM S TX
CONSISTENT WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. OVERALL
KEPT POPS ON THE HIGH SIDE BUT PINNING DOWN THE DETAILS IS STILL A
CHALLENGE. WPC SEEMS TO AGREE WITH HEAVY RAINFALL THREAT AS MOST
OF THE AREA MON/TUE IS IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
LOOKING AT 3HR FFG VALUES...NEED A GOOD 4-5 INCHES OF RAIN IN A 3
HR PERIOD TO GET FLASH FLOODING. CAN HOLD OFF ON ANY FLOOD WATCH
AND SEE WHAT HAPPENS WITH FIRST COUPLE ROUNDS OF PRECIP. THIS WILL
HELP DETERMINE THE NEED FOR A WATCH GIVEN THE UNCERTAINTY IN THE
FORECAST.
BEYOND TUE IT LOOKS LIKE LATE WED/THUR MAY BE ANOTHER ROUND FOR
HEAVY RAINFALL. AGAIN THE FORECAST WILL KEEP HIGH RAIN CHANCE
GOING THROUGH THUR AND THEN TAPER OFF FOR THE REST OF THE WEEK.
THE SET UP FOR THURSDAY IS VERY SIMILAR WITH A SHORT WAVE TROUGH
MOVING ACROSS THE AREA. BIG DIFFERENCE IS THAT THE ECMWF SEEMS TO
HAVE THIS WAVE COMING ACROSS WED AFTERNOON WITH THE GFS HAVING TWO
WEAK WAVES...ONE WED AFTERNOON AND ANOTHER BY 12Z THUR. GOING INTO
THE END OF THE WEEK...UPPER LEVEL RIDGING DEVELOPS OVER TX AND
SHOULD SUPPORT LOWER POPS AND A DRY FORECAST. THIS MAY ALSO ALLOW
FOR MAX TEMPS IN THE UPPER 80S.
39
&&
.MARINE...
MODERATE TO STRONG SOUTHEAST WINDS AND ELEVATED SEAS ARE EXPECTED
TO CONTINUE OVER THE BAYS AND COASTAL WATERS TONIGHT AS THE
PRESSURE GRADIENT REMAINS TIGHT ACROSS THE AREA. A WEAK FRONTAL
BOUNDARY IS STILL EXPECTED TO EDGE INTO THE NORTHERN PARTS OF
SOUTHEAST TEXAS LATE TONIGHT AND ON INTO EARLY MONDAY MORNING.
THIS FRONT WILL HELP TO WEAKEN THE GRADIENT AND ALLOW FOR
DECREASED WINDS AND SEAS FOR THE FIRST PART OF THE WEEK. AS THE
FRONT SLOWLY WASHES OUT...ONSHORE WINDS ARE EXPECTED TO SLOWLY
INCREASE DURING THE LATTER PART OF THE WEEK AND ON INTO NEXT
WEEKEND.
THE PERSISTENT ONSHORE WINDS CONTINUE TO SUPPORT STRONG RIP
CURRENTS AND THE POSSIBILITY OF ELEVATED TIDES. LEVELS COULD
APPROACH 3 FEET FOR LOCATIONS IN AND AROUND THE HOUSTON SHIP
CHANNEL AND ALONG THE GULF FACING BEACHES OF THE BOLIVAR PENINSULA
THIS AFTERNOON AND THIS EVENING. WAVE RUN-UP HAS THE POTENTIAL TO
BE A PROBLEM FOR LOW LYING AREAS ALONG THE BOLIVAR PENINSULA. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 84 68 76 68 / 80 60 80 70 60
HOUSTON (IAH) 74 85 70 81 70 / 30 60 70 70 40
GALVESTON (GLS) 76 82 75 80 74 / 20 50 60 60 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 AM CDT MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1235 PM CDT SUN MAY 10 2015
.AVIATION...
SCT/BKN DECKS AROUND 4000 FEET ARE ANTICIPATED THIS AFTERNOON AT
OUR NORTHERN SITES (IAH/CXO/UTS/CLL) WITH POSSIBLE MVFR CEILINGS
(2000-3000 FEET) AT OUR SOUTHERN SITES (HOU/SGR/LBX/GLS). RADAR IS
SHOWING SOME SCATTERED -SHRA BEGINNING TO DEVELOP ACROSS THE AREA
TOO...SO WILL HAVE VCSH TO COVER THAT FOR NOW. IF WE WARM UP ENOUGH...
SOME TSRA WILL BE POSSIBLE. EXPECT SSE/SE WINDS TO BE AROUND 15 TO 20
KNOTS AND GUSTY. THIS EVENING AND OVERNIGHT AS WINDS DECREASE...EYES
BEGIN TO TURN TOWARD A LINE OF SHRA/TSRA EXPECTED TO DEVELOP OFF TO
OUR W AND NW. LAST COUPLE OF HRRR MODEL RUNS HAVE BEEN SHOWING THIS
POSSIBLE STRONG/SEVERE LINE MOVING INTO THE CLL/UTS AREAS LATER THIS
EVENING. HAVE GONE AHEAD AND ADDED VCTS TO THOSE TAFS TO ACCOUNT FOR
THIS POSSIBILITY. FURTHER SOUTH...NOT REAL CONFIDENT ON WHAT THIS
POSSIBLE LINE OF STORMS WILL LOOK LIKE AS IT SLOWLY EDGES ITS WAY
TO THE E AND SE TOWARD THE CXO/IAH AREA. SINCE IT HAS A CHANCE ON
STAYING INTACT...WENT AHEAD AND ADDED VCTS AT CXO BEFORE SUNRISE
AND BETWEEN IAH AND GLS AFTER SUNRISE. EXPECT TAF AMENDMENTS LATER
THIS AFTERNOON AND THIS EVENING AS WE SEE HOW THIS LINE TAKES SHAPE.
42
&&
.PREV DISCUSSION... /ISSUED 1039 AM CDT SUN MAY 10 2015/
UPDATE...
MORNING FORECAST UPDATE.
DISCUSSION...
THUNDERSTORM ACTIVITY CONTINUES TO INCREASE OVER THE NW HILL
COUNTRY NE TOWARDS C TX. TORNADO WATCH HAS BEEN ISSUED TO THE W
AND NW OF HGX FORECAST AREA. SPC HAS SLIGHT RISK OF SEVERE STORMS
MAINLY FOR TONIGHT NORTH OF A BRENHAM TO LUFKIN LINE. AN ENHANCED
RISK OF SEVERE STORMS IS JUST TO THE NW OF A COLLEGE STATION TO
CROCKETT LINE. THE EXPECTATION IS THAT A LINE OF SCATTERED STORMS
WILL FORM OVER C TX AND THEN FORM A SOLID SQUALL LINE LATER THIS
AFTERNOON AND TONIGHT. THIS SYSTEM COULD THEN MOVE INTO SE TX.
THIS AFTERNOON THERE WILL BE QUITE A BIT OF INSTABILITY AND STRONG
SHEAR TO SUPPORT ROTATING STORMS OVER C TX HENCE THE TORNADO
WATCH. INSTABILITY SHOULD DECREASE THIS EVENING OVER SE TX AND NOT
BE QUITE AS SUPPORTIVE OF SEVERE STORMS. THE OTHER QUESTION FOR
SEVERE WEATHER OVER SE TX WILL BE CAPPING. LOOKING AT 12Z
SOUNDINGS FROM DRT...CRP...LCH IT IS HARD TO GET A HANDLE ON THE
CAPPING OVER OUR AREA. DRT AND LCH DO NOT HAVE MUCH OF A CAP SO
LOOKS LIKE THERE WILL BE A TIGHT GRADIENT ON WHERE THE CAP EXISTS
OR IS WEAK ENOUGH THAT HEATING CAN OVERCOME THE CAP. CRP SHOWS A
SUBSTANTIAL CAP BUT LOOKING AT AMDAR/ACARS SOUNDINGS OVER THE
AREA THINK HOUSTON IS JUST ENOUGH CAPPED TO LIMIT THUNDERSTORM
ACTIVITY. AREAS TO NORTH WHERE SPC HAS SEVERE OUTLOOK WILL NEED TO
BE MONITORED. FOR NOW ONLY CHANGES TO THE FORECAST WAS TO DECREASE
POPS A BIT THIS AFTERNOON AND ADJUST TONIGHT`S POPS FOR TIMING OF
CONVECTION MOVING INTO THE AREA FROM C TX.
FOR THE AFTERNOON FORECAST WE ARE REALLY GOING TO HAVE TO LOOK
HARD AT RAINFALL TOTALS AND POTENTIAL FOR HEAVY RAINFALL/FLOODING.
RIGHT NOW WPC HAS MUCH OF SE TX IN A SLIGHT RISK OF EXCESSIVE
RAINFALL FOR MONDAY AND TUESDAY. THIS IS ALSO WHEN SEVERAL
ATMOSPHERIC PARAMETERS COMBINE TO SUPPORT THAT THREAT. BUT THE
DETAILS OF HOW MUCH RAIN...WHERE AND WHEN ARE STILL A CHALLENGE
DUE TO TIMING A SHORTWAVE TROUGH COMING ACROSS THE AREA.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 86 72 84 68 77 / 30 70 70 80 80
HOUSTON (IAH) 86 73 86 71 81 / 30 30 60 80 60
GALVESTON (GLS) 83 76 83 74 80 / 20 20 50 70 70
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...42