Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/25/15
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
727 PM MDT FRI APR 24 2015
.UPDATE...
ISSUED AT 722 PM MDT FRI APR 24 2015
MINOR POP ADJUSTMENTS TO GRIDS AS SHOWERS HAVE BEEN MORE ISOLATED
IN NATURE SO FAR THIS EVENING. HRRR HINTING AT AN INCREASE IN
COVERAGE LATE TONIGHT INTO THE EARLY MORNING HOURS...FAVORING
EAST CENTRAL UTAH AS THE NEXT WAVE APPROACHES. ADDITIONAL UPDATES
LIKELY AS THE NIGHT PROGRESSES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 359 PM MDT FRI APR 24 2015
NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE LATE
AFTERNOON AS H5 DIFLUENCE KEEPS MOST OF THE ACTIVITY OVER THE
MOUNTAIN TERRAIN OF WESTERN COLORADO. ISOLATED SHOWERS AND A
STRIKE OR TWO OF LIGHTNING CANNOT BE RULED OUT IN EASTERN UTAH AS
WELL...BUT DRIER AIR IS CURRENTLY SEEN ON SATELLITE IN EASTERN
UTAH SO ANYTHING THAT DEVELOPS THIS EVENING THERE WILL BE MAINLY
GUSTY WINDS. THIS SMALL `BREAK` OF DRIER AIR WILL SHIFT INTO
WESTERN COLORADO TONIGHT...SO ACTIVITY IS EXPECTED TO DECREASE
AROUND SUNSET UNTIL JUST BEFORE MIDNIGHT. SHORT TERM MODELS
INDICATE RAIN MOVING INTO SW COLORADO BY 10 OR 11 PM TONIGHT AND
NE UTAH JUST AFTER MIDNIGHT.
CLOUDY AND SHOWERY DAY ON TAP FOR SATURDAY AS A LEAD UPPER TROUGH
MOVES ACROSS NW CO IN THE MORNING. MODELS ARE CONSISTENT WITH A NERN
PACIFIC JET DIGGING THE MAIN BUT SPLITTING TROUGH SOUTH THROUGH THE
GREAT BASIN ON SATURDAY AND EVENTUALLY FORMING A CLOSED LOW OVER
ERN AZ BY MIDDAY SUNDAY. THIS LOW THEN TRACKS ACROSS CENTRAL NM
SUNDAY AFTERNOON/NIGHT. SHOULD SEE PRECIPITATION RAMP UP AGAIN
LATER SAT NIGHT AND SUNDAY MORNING AS THE 700 MB TROUGH AND COLD
FRONT COME THROUGH WITH PRECIPITABLE WATER VALUES OF 0.5 TO 0.7
INCH. FLOW SWITCHES FAIRLY QUICKLY TO EASTERLY SUNDAY AFTERNOON.
NAM AND TO SOME EXTENT THE GFS TRY TO BRIEFLY WRAP SOME DRIER AIR
BACK IN MIDDAY SUNDAY ON THE 305K ISENTROPIC SURFACE (ROUGHLY
700-600 MB) BUT THEN QUICKLY FILLS IT IN AS THE EASTERLY FLOW
PUSHES MOISTURE OVER THE DIVIDE. TEMPS ALOFT NOT OVERLY COLD
HOWEVER...SO SNOW LEVELS SHOULD REMAIN FAIRLY HIGH OUTSIDE OF THE
STRONGER CONVECTIVE SHOWERS/T-STORMS THAT COULD DRIVE IT BELOW
8000 FT AT TIMES. CONFIDENCE NOT HIGH ENOUGH TO ISSUE ANY WINTER
HIGHLIGHTS HOWEVER...BUT THE POSSIBILITY EXISTS WITH MODELS
PUTTING OUT 6+ INCHES BY SUNDAY EVENING OVER THE SAN JUANS AND ELK
MTNS. WILL CONTINUE WITH A SPECIAL WEATHER STATEMENT.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 359 PM MDT FRI APR 24 2015
THE UPPER LOW MOVES INTO THE SOUTHERN PLAINS MONDAY WITH DRIER
AIR PUSHING ACROSS ERN UT INTO WRN CO. SCATTERED SHOWERS WILL
LIKELY PERSIST MAINLY ALONG THE DIVIDE WITH DAYTIME HEATING
WORKING ON THE COOLER AIR. UPPER RIDGE BUILDS OVERHEAD BY MIDWEEK
FOR A DRYING AND WARMING TREND. AFTERNOON TEMPS WILL RISE ABOVE
NORMAL. MAY SEE A CHANCE OF SHOWERS LATE IN THE WEEK AS MODELS
BRING A PACIFIC TROUGH INLAND AND ACROSS THE NORTHERN ROCKIES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 359 PM MDT FRI APR 24 2015
A TRANSIENT RIDGE BUILDS OVER THE AREA INTO THE EVENING HELPING
TO LIMIT CONVECTIVE SHOWERS. STILL SCT -SHRA/-SHSN ISOLATED -TSRA
COULD PRODUCE CIGS BLO 050 AND VSBY BLO 3SM MAINLY AT HIGHER SITES
LIKE KASE AND KTEX THROUGH 03Z. AFTER A LULL IN ACTIVITY EARLY
TONIGHT...INCREASINGLY MOIST SOUTHWEST FLOW ALOFT AND APPROACHING
COLD FRONT WILL CAUSE A BROADER AREA OF SHRA AND LOW CIGS/VSBY TO
MOVE WEST TO EAST ACROSS THE AREA AFT 09Z. WIDESPREAD -SHRA/-SHSN
WITH SCT THUNDERSTORMS EXPECTED AFTER 18Z SATURDAY WITH CIGS BLO
050 AND VIS BLO 3SM AT TIMES IN THE HEAVIEST SHOWERS. MTN TOPS
WILL BE OBSCD AT TIMES IN SHSN. SNOW LEVEL AROUND 10000FT EXCEPT
DOWN TO 8000FT IN HEAVIEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...JAM/JAD
LONG TERM...JAD
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
355 PM EDT THU APR 23 2015
.SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A COMPLEX
UPPER LEVEL PATTERN ACROSS THE CONUS. SPLIT FLOW ARRIVES OVER
NORTHERN CALIFORNIA WITH ONE BRANCH PUSHING INTO SOUTH-CENTRAL
CANADA AND ANOTHER CARVING A DEEP TROUGH THROUGH THE DESERT
SOUTHWEST/BAJA REGION. FURTHER EAST DOWNSTREAM WE FIND A DEEP AND
UNSEASONABLY COLD TROUGH IN PLACE ACROSS THE GREAT
LAKES/NORTHEASTERN STATES. SOUTHERN STREAM FLOW IS MOVING NORTH OUT
OF THE TROPICAL PACIFIC TO THE EAST OF THE BAJA TROUGH AND THEN
BECOMING MORE ZONAL AS TO MOVES OVER THE NORTH-CENTRAL GULF
COAST...INCLUDING THE FLORIDA PENINSULA.
AT THE SURFACE...A WEAK SURFACE BOUNDARY THAT SET UP ACROSS THE
NORTHEAST GULF OF MEXICO HAS BEEN THE FOCUS FOR PERSISTENT SHOWERS
AND THUNDERSTORM MOVING ASHORE TODAY. THE AREAS EFFECTED HAVE
SHIFTED THROUGH THE DAY...BUT WE HAVE NOW SEEN DECENT RAINFALL FOR
JUST ABOUT EVERYONE...WITH THE EXCEPTION OF PARTS OF LEE/CHARLOTTE
COUNTIES...AND ALSO LEVY COUNTY. THE CURRENT CONVECTIVE BAND EXTENDS
FROM THE MANATEE/SARASOTA COASTS INLAND THROUGH DESOTO AND SOUTHERN
HIGHLANDS COUNTIES. RADAR SHOWS A DEFINED OUTFLOW BOUNDARY HAS
SHIFTED SOUTH FROM THIS CONVECTIVE BAND AND APPEARS TO BE SLOWLY IN
INFLOW. CONVECTIVE ORGANIZATION AND STRENGTH OF THE CELLS HAS BEEN
ON THE DECLINE DURING THE PAST HOUR...AND EXPECT THIS TREND TO
CONTINUE INTO THE EARLY EVENING. FROM PINELLAS/HILLSBOROUGH/POLK
COUNTIES NORTHWARD THE RAINFALL HAS COME TO AN END...AND A DECENT
EVENING WEATHERWISE APPEARS IN STORE.
&&
.SHORT TERM (TONIGHT THROUGH FRIDAY)...
REST OF TODAY AND TONIGHT... BAND OF SHOWER AND ISOLATE STORMS WILL
CONTINUE TO BECOME LESS ORGANIZED INTO THE EVENING AS IT SINKS
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. HAVE HIGHEST RAIN
CHANCES SOUTH OF THE TAMPA BAY AREA...WITH LITTLE TO NO ADDITIONAL
RAINFALL EXPECTED FOR THE I-4 CORRIDOR AND NORTHWARD. ALTHOUGH
ANOTHER STRONG STORM OR TWO CAN NOT BE RULED OUT ACROSS THE SOUTHERN
HALF OF THE AREA...THE THREAT FOR SEVERE WEATHER APPEARS TO BE
RAPIDLY DECLINING AS WELL.
ONCE THIS BAND OF STORMS DISSIPATES LATER THIS EVENING...AM
ANTICIPATING A GENERALLY DRY AND SEASONABLE OVERNIGHT PERIOD AS HIGH
PRESSURE BEGINS TO BUILD IN FROM THE NORTH. THERE MAY BE A BIT OF
FOG LATE AT NIGHT ACROSS THE INTERIOR...BUT SIGNIFICANT COVERAGE OR
VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT THIS TIME. LOW
TEMPERATURES TONIGHT GENERALLY IN THE 60S...WITH LOWER 70S ALONG THE
IMMEDIATE COAST FROM TAMPA BAY SOUTHWARD.
FRIDAY IS SHAPING UP TO BE A MUCH QUIETER DAY IN TERMS OF
THUNDERSTORMS. THE DEEP LAYER MOISTURE WILL HAVE BEEN SCOURED OUT
FOR THE MOST PART MAKING THE COLUMN MORE HOSTILE TOWARD DEEP
CONVECTION. IN ADDITION...MID-LEVEL TEMPS ARE FORECAST BY THE
GUIDANCE SUITE TO BE 2-3 DEGREES WARMER ON FRIDAY THAN THEY ARE
TODAY. ALL THIS SUGGESTS A GENERALLY INACTIVE SEA BREEZE
THUNDERSTORM PATTERN. HIRES GUIDANCE ENSEMBLES SUGGEST A FEW WIDELY
SCT STORMS LATE IN THE DAY ALONG THE SEA-BREEZE...GENERALLY SOUTH OF
THE TAMPA BAY AREA. WILL HAVE 20-30% POPS AFTER 19-20Z SOUTH OF
TAMPA BAY FOR THIS POTENTIAL...HOWEVER ANY STORMS SHOULD BE BRIEF IN
DURATION AND LIFE CYCLE GIVEN THE MORE HOSTILE COLUMN ALOFT.
AFTERNOON TEMPERATURES RISING WELL INTO THE 80S FOR MOST
SPOTS...WITH EVEN SOME LOWER 90S ACROSS THE SOUTHERN ZONES.
&&
.LONG TERM (SATURDAY THROUGH NEXT THURSDAY)... SAT-SUN...UPPER LEVEL
RIDGING ACROSS THE AREA FLATTENS AS A SHORT WAVE TROUGH TRACKS
ACROSS THE OHIO VALLEY AND CROSSES THE MID-ATLANTIC STATES.
MEANWHILE A FRONT SAGS IN ALONG THE GULF COAST AND THROUGH THE SE
U.S. AS IT WEAKENS...ATLANTIC HIGH PRESSURE RIDGES IN ACROSS AND
SOUTH OF THE SOUTHERN HALF OF FL.
MON-TUE...AN UPPER TROUGH/LOW MOVES OUT OF THE FOUR CORNERS REGION
TO THE EASTERN PLAINS WITH WEAK RIDGING CONTINUING ACROSS THE GULF
REGION. THE FRONT IN THE SE U.S. SETTLES INTO FL. THE ECMWF HAS A
BROAD BOUNDARY ACROSS CENTRAL FL WHILE THE GFS IS MORE CONCENTRATED
IN THE NORTHERN HALF OF THE STATE.
WED-THU...THE UPPER TROUGH BROADENS OVER THE EASTERN CONUS AS IT
DROPS DOWN INTO THE GULF THEN SLIDES EAST..MORE SLOWLY IN THE ECMWF
WHILE THE GFS IS FASTER WITH A SLIGHTLY SHARPER TROUGH. AT THE
SURFACE LOW PRESSURE MOVES EAST WITH A TRAILING COLD FRONT. HERE THE
ECMWF AND GAS ARE SIMILAR WITH THE TIMING ALTHOUGH THE ECMWF HAS THE
LOW IN THE GULF AND MOVING ACROSS FL WHILE THE GFS KEEPS THE LOW IN
THE GULF COASTAL AND SOUTHERN STATES.
EXPECT SOME LOW POPS WITH SHOWERS AND A FEW THUNDERSTORMS MAINLY
NORTH AND INTERIOR INTO EARLY MON. RAIN CHANCES THEN GRADUALLY
INCREASE THROUGH MIDWEEK WITH SOME STRONG STORMS AND HEAVY RAIN
POSSIBLE. SHOWERS AND STORMS THEN TREND DOWN FOR THE END OF THE
PERIOD. TEMPERATURES WILL START OFF ABOVE NORMAL THEN SLOWLY
DECREASE TO NEAR NORMAL...WITH THE NORTH SLIGHTLY BELOW.
&&
.AVIATION... BAND OF CONVECTION STRETCHING FROM NEAR KSRQ TO LAKE
OKEECHOBEE WILL CONTINUE TO SLOWLY SINK SOUTHWARD INTO THE EARLY
EVENING. HAVE INCLUDED VCTS FOR KPGD...BUT APPEARS UNLIKELY THIS
LINE OF STORMS WILL REACH KFMY/KRSW. NORTH OF THE BAND FOR THE I-4
CORRIDOR TERMINALS...IT APPEARS THAT THE CONVECTION HAS FINALLY COME
TO AN END. THEREFORE VIS/CIG RESTRICTIONS WILL BE POSSIBLE FOR
KSRQ/KPGD THE NEXT SEVERAL HOURS...BUT THEREAFTER WILL BE
FORECASTING VFR THROUGH REMAINDER OF THE TAF PERIOD.
&&
.MARINE... A WEAK BOUNDARY OVER THE NORTHEAST GULF OF MEXICO WEAKENS
TONIGHT AS HIGH PRESSURE ATTEMPTS TO BUILD IN FROM THE NORTH. THIS
RIDGE SLIDES SOUTH TO THE FLORIDA STRAITS BY SATURDAY. WINDS AND
WAVES ARE GENERALLY EXPECTED TO REMAIN BELOW 15 KNOTS THROUGH THE
WEEKEND.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AS RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 72 87 73 87 / 10 10 10 0
FMY 73 90 73 89 / 10 30 10 0
GIF 69 88 71 89 / 20 20 0 30
SRQ 71 84 73 86 / 10 10 10 0
BKV 66 88 66 88 / 10 20 0 10
SPG 74 86 75 85 / 10 10 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT THU APR 23 2015
.DISCUSSION...
CONVECTIVE CLUSTER DVLPD JUST N OF KTBW ARND SUNRISE AND HAS PUSHED
STEADILY INTO THE E CENTRAL PENINSULA N OF SR-60. LATEST SAT IMAGERY
SHOWS WARMING TOPS ASSCD WITH THIS CLUSTER...AND OVERALL CG LTG
ACTIVITY HAS BEEN LOW. EVEN SO...KTBW RADAR SHOWS CONVECTION CELLS
EXTENDING WELL INTO THE NE GOMEX. ACTIVITY IS EMBEDDED WITHIN DEEP
AND BRISK MID/UPR LVL WRLY FLOW.
LCL AIRMASS UNDERWENT RAPID MODIFICATION OVERNIGHT...PWATS FROM THE
KTBW RAOBS INCREASED FROM 1.1" AT 00Z LAST NIGHT TO 1.8" AT 12Z THS
MRNG...KXMR VALUES INCREASED AS WELL THOUGH QUITE AS RAPID 1.0" AT
00Z TO 1.2" AT 12Z. COMPETING FRONTAL BOUNDARIES OVER THE FL
PENINSULA/NE GOMEX AND THE DEEP SOUTH WILL PUT THE OLD SQUEEZE PLAY
ON CENTRAL FL THAT WILL MAINTAIN THE MID/UPR LVL WRLY FLOW. UPSTREAM
MOISTURE IS PLENTIFUL AS RAP ANALYSIS SHOWS H100-H70 MEAN RH VALUES
BTWN 80-90PCT...H85-H50 VALUES BTWN 70-80PCT. MID LVL ANALYSIS ALSO
SHOWS A PAIR OF VORT RIPPLES IN THE H85-H50 LYR OVER THE ERN GOMEX
AND SW FL PENINSULA. H70 TEMPS ARND 5C AND H50 TEMPS ARND -10C ARE
YIELDING LAPSE RATES ARND 6.0C/KM.
BASED ON LATEST RADAR TREND AND WX ANALYSIS...WILL NUDGE POS UP TO
50-60PCT FROM NRN BREVARD/SEMINOLE/SRN LAKE CO SWD...ESP ALNG THE
COASTAL COUNTIES FROM BREVARD SWD AS LCL MOS GUIDANCE IS
SUGGESTING AN EAST COAST SEA BREEZE DVLPG FOR A FEW HRS THIS AFTN.
WILL NUDGE POPS OVER VOLUSIA/NRN LAKE UP TO 30/40PCT.
&&
.AVIATION...THRU 24/12Z
SFC WINDS: THRU 24/00Z...S/SW 5-9KTS...BTWN 23/16Z-23/22 S/SE 5-9KTS
COASTAL SITES ASSCD WITH THE EAST COAST SEA BREEZE. BTWN 24/00Z-
24/06Z... SW 3-7KTS. AFT 24-06Z...W/NW AOB 5KTS.
VSBYS/WX/CIGS: THRU 23/18Z...SCT MVFR SHRAS/ISOLD IFR TSRAS N OF
KVRB-KLAL MVG E 15-20KTS. BTWN 23/18Z-23/24Z...SCT MVFR SHRAS/ISOLD
IFR TSRAS ALL SITES. BTWN 24/00Z-24/03Z...CHC IFR TSRAS COASTAL
SITES...BCMG VFR INTERIOR SITES. AFT 24/03Z...VFR ALL SITES.
&&
.MARINE...
LOOSE SFC PGRAD OVER THE LCL ATLC WITH COMPETING FRONTAL TROFS OVER
THE FL STRAITS AND THE DEEP SOUTH AND A WEAK SFC RIDGE TUCKED IN
BETWEEN. FAVORABLE CONDS WITH S/SWRLY GRADIENT WINDS AOB 10KT...BCMG
SE NEAR THE COAST THIS AFTN WITH THE FORMATION OF THE EAST COAST SEA
BREEZE. SEAS AOB 2FT. OFFSHORE MOVING SHRAS/TSRA THIS AFTN INTO EVNG
CAPABLE OF GENERATING LCL SFC GUSTS ARND 34KTS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...VOLKMER
AREA FORECAST DISCUSSION...UPDATE
NWS TAMPA BAY RUSKIN FL
800 AM EDT THU APR 23 2015
.UPDATE... A CLUSTER OF THUNDERSTORMS WILL MOVE ASHORE FROM HERNANDO
COUNTY SOUTHWARD TO PINELLAS COUNTY THROUGH 14/15Z. ADDITIONAL
SHOWER DEVELOPMENT IS BEGINNING FURTHER NORTH THAT WILL LIKLEY
EVENTUALLY IMPACT CITRUS AND LEVY COUNTY THIS MORNING. MOSTLY CLEAR
SKIES OVERNIGHT ACROSS THE NORTHERN NATURE COAST/BIG BEND REGION
ALLOWED FOR SOME RADIATIONAL COOLING TO TAKE PLACE. AS OF 7AM WE SAW
TEMPERATURES/DEWPOINTS CONSIDERABLY COOLER OVER THESE NORTHERN AREAS
THAT DOWN TOWARD THE I-4 CORRIDOR AND SOUTHWARD. THE COOLING HAS
ALLOWED FOR A SUBTLE LAND BREEZE/DRAINAGE FLOW TO DEVELOP AND TURN
THE WINDS OFFSHORE ALONG THE NATURE COAST. THIS PROCESS HAS DONE TWO
THINGS. ONE THE DIFFERENTIAL COOLING HAS RESULTED IN SUBTLE LOW
LEVEL FRONTOGENESIS ACROSS APALACHEE BAY...AND ALSO SET UP A DECENT
DIRECTIONAL CONVERGENCE ZONE OVER OUR NORTHERN WATERS. IT IS THIS
SURFACE CONVERGENCE/FOCUS AND THE FRONTOGENESIS CIRCULATION THAT
SEEMS TO BE THE MAIN PLAYER IN THIS DEVELOPMENT OF THIS CONVECTIVE
CLUSTER. WILL EXPECT TO CONTINUE SEEING DEVELOPMENT ACROSS THIS ZONE
UNTIL DIURNAL HEATING IS ABLE TO WEAKER/REVERSE THE LAND BREEZE FLOW
OFF THE NATURE COAST. WILL RAISE POPS ALONG AND NORTH OF THE I-4
CORRIDOR FOR THE REST OF THE MORNING. STILL APPEARS THAT ONCE THIS
INITIAL ROUND OF STORMS ACROSS THE NORTHERN FORECAST AREA ENDS THAT
THE MAJORITY OF SECOND HALF OF THE DAY CONVECTION WILL BE INLAND
ACROSS OUR SOUTH-CENTRAL ZONES. HOWEVER...WILL CONTINUE TO MONITOR
THE LATEST CONVECTION ALLOWING GUIDANCE AND ADJUST THIS AFTERNOON
FORECAST BASED ON HOW THIS GREATER THAN EXPECTED MORNING ACTIVITY
EFFECTS THE SEA-BREEZE FORMATION.
&&
.PREVIOUS DISCUSSION (TODAY-FRIDAY)... A CONVECTIVE COMPLEX OVER THE
CENTRAL-EASTERN GULF OF MEXICO EARLY THIS MORNING IS ASSOCIATED WITH
A VORT MAX THAT WILL CONTINUE TO SHIFT EASTWARD THROUGH THE REST OF
THE MORNING HOURS. RADAR IMAGERY SHOWS SOME SHOWERS OVER THIS REGION
AND WOULD EXPECT THIS ACTIVITY TO SHIFT EASTWARD AS WELL...MAKING IT
INTO OUR SOUTHERN COASTAL WATERS AND POSSIBLY EVEN COASTAL SOUTHWEST
FLORIDA BEFORE DAYBREAK. THIS IS SUPPORTED BY THE LATEST HRRR AND
OTHER HIGH-RES GUIDANCE. FOR THE REST OF TODAY...ANOTHER VORT MAX
WILL APPROACH FROM THE NORTHWEST WITH WEAK HIGH PRESSURE AT THE
SURFACE AND A FRONTAL BOUNDARY MOVING INTO THE SOUTHEAST. AS FAR AS
RAIN CHANCES GO...EXPECT THE ACTIVITY OVER THE GULF TO SHIFT
SOUTHEAST THROUGH THE MORNING AND THEN WE WILL TRANSITION TO MORE
SEA-BREEZE/DIURNAL SHOWERS AND THUNDERSTORMS FOR THE AFTERNOON
HOURS...WITH THE BEST CHANCES OVER INLAND AREAS AS THE WEST COAST
SEA BREEZE FORMS AND SHIFTS INLAND. THE WEAK FRONTAL BOUNDARY WILL
SINK SOUTH INTO NORTHERN FLORIDA TONIGHT INTO EARLY FRIDAY WITH
MOSTLY QUIET CONDITIONS EXPECTED ACROSS THE FORECAST AREA. UPPER-
LEVEL RIDGING WILL START TO BUILD OVER THE GULF DURING THE DAY WITH
SURFACE HIGH PRESSURE CENTERED TO THE NORTHEAST. SHOWER AND
THUNDERSTORM ACTIVITY DURING THE AFTERNOON WILL BE FOCUSED MAINLY
OVER SOUTHWEST FLORIDA. AS FAR AS TEMPERATURES...STILL LOOKING AT
ABOVE NORMAL VALUES TO END THE WEEK.
.LONG TERM (FRIDAY NIGHT-THURSDAY)...
CUT-OFF U/L LOW WILL MOVE OVER NEW ENGLAND WITH THE TROUGH AXIS
WELL OFF THE EASTERN SEABOARD. WEST COAST TROUGH WILL PERSIST WITH
BROAD RIDGING DOWNSTREAM OVER THE GULF OF MEXICO WITH A RIDGE AXIS
NORTH THROUGH THE TENNESSEE VALLEY. AN U/L DISTURBANCE WILL BE
EJECTED EAST ACROSS THE MID/LOWER MISSISSIPPI VALLEY FRIDAY NIGHT
TO THE TENNESSEE VALLEY ON SATURDAY. ONSHORE WESTERLY BOUNDARY
LAYER FLOW ACROSS THE FLORIDA PENINSULA WILL PUSH THE WEST COAST
SEA BREEZE BOUNDARY INLAND RATHER QUICKLY...WHICH WILL KEEP MOST
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY EAST OF THE FORECAST
AREA.
U/L ENERGY OVER THE PACIFIC NORTHWEST WILL SINK SOUTHEAST AND CUT-
OFF OVER THE FOUR CORNERS AREA SUNDAY WITH STRONG U/L QUASI-ZONAL
FLOW PERSISTING ACROSS THE SOUTHERN TIER OF THE U.S. A WEAK FRONTAL
BOUNDARY WILL STALL ACROSS THE SOUTHEAST U.S. WITH DEEP TROPICAL
MOISTURE SOUTH OF THE BOUNDARY ACROSS THE FLORIDA PENINSULA. A WEAK
U/L DISTURBANCE WILL TRACK ACROSS THE FLORIDA PENINSULA SUNDAY WITH
A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY NORTH OF THE
TAMPA BAY AREA AND OVER THE INTERIOR. THE U/L LOW OVER THE
SOUTHWEST U.S. WILL BEGIN TO OPEN UP AND PUSH EAST ACROSS THE
SOUTHERN PLAINS MONDAY WHICH WILL INDUCE WEAK U/L RIDGING OVER THE
GULF OF MEXICO. COMBINATION OF DAYTIME HEATING AND SUFFICIENT DEEP
LAYER MOISTURE AND WEAK ATMOSPHERIC INSTABILITY WILL CREATE A CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
MONDAY AFTERNOON.
COMPLEX PATTERN TAKING SHAPE MIDDLE OF NEXT WEEK AS THE U/L LOW
MOVING OUT OF THE SOUTHERN PLAINS MAY BE ABSORBED BY NORTHERN STREAM
ENERGY OVER THE MID MISSISSIPPI RIVER VALLEY ON TUESDAY. THIS WILL
CREATE GOOD U/L DIFFLUENCE OVER THE LOWER MISSISSIPPI VALLEY WITH AN
AREA OF LOW PRESSURE DEVELOPING AND PUSHING SLOWLY EAST TO THE
SOUTHEAST U.S. ON WEDNESDAY. HIGH DEGREE OF UNCERTAINTY ON THIS
EVOLVING SYSTEM AS THE U/L PATTERN SUGGESTS A DIGGING STRONG U/L
DISTURBANCE APPROACHING THE SOUTHEAST U.S. WITH STRONG DYNAMICS/LIFT
DEVELOPING OVER WEST CENTRAL AND SOUTHWEST FLORIDA TUESDAY NIGHT AND
WEDNESDAY. A COLD FRONT WILL MOVE ACROSS THE EASTERN GULF OF MEXICO
AND THE FLORIDA PENINSULA TUESDAY NIGHT AND WEDNESDAY WITH
SHOWERS/THUNDERSTORMS LIKELY DEVELOPING AHEAD OF THE FRONT AND
SPREADING OVER THE FORECAST AREA WITH A FEW STRONG STORMS POSSIBLE
WITH LOCALLY HEAVY RAIN.
U/L ENERGY WILL LIFT RAPIDLY NORTHEAST ON THE EAST SIDE OF THE L/W
TROUGH WEDNESDAY NIGHT AND THURSDAY WITH THE SURFACE LOW LIFTING TO
THE MID ATLANTIC COAST. DRIER COOLER AIR WILL ADVECT ACROSS WEST
CENTRAL AND SOUTHWEST FLORIDA IN THE WAKE OF THE COLD FRONT.
&&
.AVIATION... CLUSTER OF SHOWER AND STORMS MOVING ASHORE WILL IMPACT
KTPA/KPIE/KLAL THIS MORNING WITH POTENTIAL BRIEF HEAVY DOWNPOURS.
TERMINALS SOUTH OF I-4 CORRIDOR SHOULD SEE A CONTINUATION OF VFR
CONDITIONS THIS MORNING...FOLLOWED BY A CHANCE FOR AFTERNOON STORMS
DEVELOPING ALONG THE SEA BREEZE.
&&
.MARINE...
SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE COASTAL WATERS
TODAY...BUT OTHERWISE EXPECT BENIGN CONDITIONS TO CONTINUE
THROUGH THE FIRST PART OF THE WEEKEND WITH NO HEADLINES EXPECTED.
WINDS WILL INCREASE BRIEFLY LATE SATURDAY NIGHT INTO SUNDAY...BUT
THEN DIMINISH AGAIN FOR EARLY NEXT WEEK.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AS RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 85 73 89 72 / 40 20 20 0
FMY 88 72 89 73 / 50 20 30 10
GIF 88 70 88 71 / 50 20 20 10
SRQ 83 71 86 70 / 40 30 10 0
BKV 86 66 88 66 / 30 20 10 0
SPG 84 75 86 75 / 40 30 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...05/CARLISLE
LONG TERM/DECISION SUPPORT...13/OGLESBY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
421 AM EDT THU APR 23 2015
.SHORT TERM (TODAY-FRIDAY)...
A CONVECTIVE COMPLEX OVER THE CENTRAL-EASTERN GULF OF MEXICO EARLY
THIS MORNING IS ASSOCIATED WITH A VORT MAX THAT WILL CONTINUE TO
SHIFT EASTWARD THROUGH THE REST OF THE MORNING HOURS. RADAR
IMAGERY SHOWS SOME SHOWERS OVER THIS REGION AND WOULD EXPECT THIS
ACTIVITY TO SHIFT EASTWARD AS WELL...MAKING IT INTO OUR SOUTHERN
COASTAL WATERS AND POSSIBLY EVEN COASTAL SOUTHWEST FLORIDA BEFORE
DAYBREAK. THIS IS SUPPORTED BY THE LATEST HRRR AND OTHER HIGH-RES
GUIDANCE. FOR THE REST OF TODAY...ANOTHER VORT MAX WILL APPROACH
FROM THE NORTHWEST WITH WEAK HIGH PRESSURE AT THE SURFACE AND A
FRONTAL BOUNDARY MOVING INTO THE SOUTHEAST. AS FAR AS RAIN CHANCES
GO...EXPECT THE ACTIVITY OVER THE GULF TO SHIFT SOUTHEAST THROUGH
THE MORNING AND THEN WE WILL TRANSITION TO MORE SEA-BREEZE/DIURNAL
SHOWERS AND THUNDERSTORMS FOR THE AFTERNOON HOURS...WITH THE BEST
CHANCES OVER INLAND AREAS AS THE WEST COAST SEA BREEZE FORMS AND
SHIFTS INLAND. THE WEAK FRONTAL BOUNDARY WILL SINK SOUTH INTO
NORTHERN FLORIDA TONIGHT INTO EARLY FRIDAY WITH MOSTLY QUIET
CONDITIONS EXPECTED ACROSS THE FORECAST AREA. UPPER-LEVEL RIDGING
WILL START TO BUILD OVER THE GULF DURING THE DAY WITH SURFACE HIGH
PRESSURE CENTERED TO THE NORTHEAST. SHOWER AND THUNDERSTORM
ACTIVITY DURING THE AFTERNOON WILL BE FOCUSED MAINLY OVER
SOUTHWEST FLORIDA. AS FAR AS TEMPERATURES...STILL LOOKING AT ABOVE
NORMAL VALUES TO END THE WEEK.
.LONG TERM (FRIDAY NIGHT-THURSDAY)...
CUT-OFF U/L LOW WILL MOVE OVER NEW ENGLAND WITH THE TROUGH AXIS
WELL OFF THE EASTERN SEABOARD. WEST COAST TROUGH WILL PERSIST WITH
BROAD RIDGING DOWNSTREAM OVER THE GULF OF MEXICO WITH A RIDGE AXIS
NORTH THROUGH THE TENNESSEE VALLEY. AN U/L DISTURBANCE WILL BE
EJECTED EAST ACROSS THE MID/LOWER MISSISSIPPI VALLEY FRIDAY NIGHT
TO THE TENNESSEE VALLEY ON SATURDAY. ONSHORE WESTERLY BOUNDARY
LAYER FLOW ACROSS THE FLORIDA PENINSULA WILL PUSH THE WEST COAST
SEA BREEZE BOUNDARY INLAND RATHER QUICKLY...WHICH WILL KEEP MOST
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY EAST OF THE FORECAST
AREA.
U/L ENERGY OVER THE PACIFIC NORTHWEST WILL SINK SOUTHEAST AND CUT-
OFF OVER THE FOUR CORNERS AREA SUNDAY WITH STRONG U/L QUASI-ZONAL
FLOW PERSISTING ACROSS THE SOUTHERN TIER OF THE U.S. A WEAK FRONTAL
BOUNDARY WILL STALL ACROSS THE SOUTHEAST U.S. WITH DEEP TROPICAL
MOISTURE SOUTH OF THE BOUNDARY ACROSS THE FLORIDA PENINSULA. A WEAK
U/L DISTURBANCE WILL TRACK ACROSS THE FLORIDA PENINSULA SUNDAY WITH
A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY NORTH OF THE
TAMPA BAY AREA AND OVER THE INTERIOR. THE U/L LOW OVER THE
SOUTHWEST U.S. WILL BEGIN TO OPEN UP AND PUSH EAST ACROSS THE
SOUTHERN PLAINS MONDAY WHICH WILL INDUCE WEAK U/L RIDGING OVER THE
GULF OF MEXICO. COMBINATION OF DAYTIME HEATING AND SUFFICIENT DEEP
LAYER MOISTURE AND WEAK ATMOSPHERIC INSTABILITY WILL CREATE A CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA
MONDAY AFTERNOON.
COMPLEX PATTERN TAKING SHAPE MIDDLE OF NEXT WEEK AS THE U/L LOW
MOVING OUT OF THE SOUTHERN PLAINS MAY BE ABSORBED BY NORTHERN STREAM
ENERGY OVER THE MID MISSISSIPPI RIVER VALLEY ON TUESDAY. THIS WILL
CREATE GOOD U/L DIFFLUENCE OVER THE LOWER MISSISSIPPI VALLEY WITH AN
AREA OF LOW PRESSURE DEVELOPING AND PUSHING SLOWLY EAST TO THE
SOUTHEAST U.S. ON WEDNESDAY. HIGH DEGREE OF UNCERTAINTY ON THIS
EVOLVING SYSTEM AS THE U/L PATTERN SUGGESTS A DIGGING STRONG U/L
DISTURBANCE APPROACHING THE SOUTHEAST U.S. WITH STRONG DYNAMICS/LIFT
DEVELOPING OVER WEST CENTRAL AND SOUTHWEST FLORIDA TUESDAY NIGHT AND
WEDNESDAY. A COLD FRONT WILL MOVE ACROSS THE EASTERN GULF OF MEXICO
AND THE FLORIDA PENINSULA TUESDAY NIGHT AND WEDNESDAY WITH
SHOWERS/THUNDERSTORMS LIKELY DEVELOPING AHEAD OF THE FRONT AND
SPREADING OVER THE FORECAST AREA WITH A FEW STRONG STORMS POSSIBLE
WITH LOCALLY HEAVY RAIN.
U/L ENERGY WILL LIFT RAPIDLY NORTHEAST ON THE EAST SIDE OF THE L/W
TROUGH WEDNESDAY NIGHT AND THURSDAY WITH THE SURFACE LOW LIFTING TO
THE MID ATLANTIC COAST. DRIER COOLER AIR WILL ADVECT ACROSS WEST
CENTRAL AND SOUTHWEST FLORIDA IN THE WAKE OF THE COLD FRONT.
&&
.AVIATION...
MAINLY VFR CONDITIONS ARE EXPECTED. THE EXCEPTION WILL BE ANY
THUNDERSTORMS THAT MOVE OVER TERMINALS...CAUSING BRIEF
RESTRICTIONS. WILL COVER THIS FOR NOW WITH VCTS MENTION AT ALL
SITES STARTING AT 18Z.
&&
.MARINE...
SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER THE COASTAL WATERS
TODAY...BUT OTHERWISE EXPECT BENIGN CONDITIONS TO CONTINUE
THROUGH THE FIRST PART OF THE WEEKEND WITH NO HEADLINES EXPECTED.
WINDS WILL INCREASE BRIEFLY LATE SATURDAY NIGHT INTO SUNDAY...BUT
THEN DIMINISH AGAIN FOR EARLY NEXT WEEK.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AS RELATIVE HUMIDITY VALUES WILL REMAIN
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 85 73 89 72 / 40 20 20 0
FMY 88 72 89 73 / 50 20 30 10
GIF 88 70 88 71 / 50 20 20 10
SRQ 83 71 86 70 / 40 30 10 0
BKV 86 66 88 66 / 30 20 10 0
SPG 84 75 86 75 / 40 30 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...05/CARLISLE
LONG TERM/DECISION SUPPORT...13/OGLESBY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
342 AM EDT THU APR 23 2015
.DISCUSSION...
TODAY AND TONIGHT...STRONG UPR ATMOSPHERIC WINDS WL CONTINUE
ACROSS THE REGION...PRODUCING A NOTABLE AMOUNT OF HIGHER LEVEL
CLOUDINESS. UNSETTLED CONDS WL BE OFFSET BY THE SOMEWHAT DRIER
OVERALL AIRMASS AND TEMPS AROUND -9C @ H5 WITH PWAT VALUES JUST
OVER AN INCH BUT RECOVERING. HAVE UNDERCUT THE HIGHER MOS
INDICATED POPS WHILE MAINTAINING MOSTLY SCT RAIN CHCS DURING THE
HEAT OF THE AFTN. LIGHT SFC GRADIENT CONDS WL LEAD TO A RICH
BOUNDARY INTERACTION ENVIRONMENT AT MID AFTERNOON WITH WLY UPR
STEERING WINDS FAVORING THE E SIDE OF THE PENINSULA FOR EVENTUAL
MOVEMENT OF SHRA/ISOLD/TS. LTST HRRR GUID KEEPS REMNANTS OF
CURRENT GULF MCS SOUTH OF THE FORECAST AREA WHILE SHOWING
ORGANIZED WEST COAST SOURCE PCPN AREA MIGRATING EWD ACROSS THE
SRN PENINSULA LATE AFTERNOON INTO EVENING.
FRIDAY...DRIEST DAY OF THE NEXT SEVERAL AS SURFACE HIGH MOVES OFF
SOUTH CAROLINA COAST AND LOW LEVEL FLOW VEERS NE/ENE IN THE
AFTERNOON ALONG WITH UPPER LEVEL RIDGE BUILDING INTO THE REGION. A
DRIER AIRMASS OVERALL WILL LIMIT CONVECTIVE COVERAGE TO FAR SRN AND
INTERIOR AREAS IN THE AFTERNOON WITH THE MORE ROBUST EAST COAST SEA
BREEZE.
HIGHS WILL RANGE FROM THE LOWER TO MID 80S COAST TO MID TO UPPER 80S
OVER THE INTERIOR. EVENING HOURS WILL REMAIN DRY WITH ANY SHOWERS
EXPECTED TO BE WEST OF THE REGION. LOWS UPPER 60S TO AROUND 70.
SAT-SUN...UPPER LEVEL RIDGE CROSSES THE STATE ON SAT AND IS QUICKLY
FLATTENED INTO SUN BY SHORTWAVE MOVING INTO THE MIDWEST/MID-
ATLANTIC. ACCOMPANYING THIS FEATURE WILL BE A SURFACE LOW CROSSING
THE MIDWEST/TN VALLEY AND PUSHING OFF THE CAROLINA COAST SUN
MORNING. ORIENTATION OF THE UPPER LEVEL FLOW WILL MEAN THE
ACCOMPANYING BOUNDARY WILL EARLY SAG INTO NORTH FLORIDA LATE
SATURDAY AND SUNDAY.
MID LEVEL MOISTURE WILL BE THE MAIN LIMITING FACTOR FOR CONVECTION
ON SATURDAY AS JET LEVEL DIVERGENCE REMAINS FAVORABLE AS WELL AS
BRISK STEERING FLOW KEEPING THE EAST COAST SEA BREEZE NEAR THE COAST
IN THE AFTERNOON. BETTER RAIN CHANCES INTO SUNDAY ESPECIALLY NORTH
OF ORLANDO AS MOISTURE ASSOCIATED WITH THE FRONT DROPS FURTHER
SOUTH.
WITHOUT THE SEA BREEZE TEMPERATURES REMAIN WELL ABOVE
NORMAL...POSSIBLY NEAR RECORDS IN SOME CASES...WITH HIGHS IN THE
UPPER 80S AND LOW 90S. OVERNIGHT LOWS IN THE 70S.
MON-WED...GFS HAS TRENDED TOWARDS THE ECMWF IN THE EXTENDED AND IS
LESS AGGRESSIVE IN POST FRONTAL DRYING ON MONDAY...KEEPING MORE
MOISTURE POOLED ACROSS THE SOUTH FLORIDA AND AROUND LAKE OKEECHOBEE
AS THE FRONT STALLS. THIS WILL KEEP RAIN CHANCES...AT LEAST ACROSS
OKEECHOBEE AND THE TREASURE COAST...SIMILAR TO SUNDAY.
GFS IS ALSO NOW SHOWING A MORE SOUTHERLY TRACK WITH THE UPPER LEVEL
LOW MEANDERING ACROSS THE SOUTHERN TIER OF THE US AND THEREFORE A
MORE SPLIT TRACK FLOW. AS WITH PREVIOUS RUNS OF THE ECMWF...THE
ASSOCIATED SURFACE LOW IS FORECAST TO TRACK ACROSS THE NORTHERN GULF
TUES AND WED AND ACROSS N FLORIDA INTO WED NIGHT. BEST RAIN CHANCES
THROUGH THESE DAYS WILL DEPEND ON WHERE THE WARM FRONTAL TYPE
BOUNDARY SETS UP ACROSS THE STATE AND HOW QUICKLY THE LOW CAN LIFT
OUT AND PULL THE FRONT THROUGH. OVERALL RAIN CHANCES CONTINUE ABOVE
NORMAL...WITH DAY TO DAY DIFFERENCES IMPOSSIBLE TO PREDICT THIS FAR
OUT. ABOVE NORMAL TEMPS CONTINUE THROUGH TUESDAY.
&&
.AVIATION...
VFR CONDS THROUGH 23/16Z WITH LCL SHRA AND CIGS NR FL 040-050
DVLPG AFT 23/18Z WITH BOUNDARY INTERACTION AND WEST COAST SOURCE
PCPN MIGRATING EWD. BEST TIMING LOOKS LATER FOR PSBL MVFR AND/OR
ISOLD IFR CONDS IN SHRA/TS FM 23/20Z-24/01Z.
&&
.MARINE...
TODAY AND TONIGHT...FAVORABLE CONDS WITH GRADIENT WINDS 10KT OR
LESS MORNING INTO AFTERNOON. OFFSHORE MOVING PCPN AREAS PSBL AFTER
MID AFTN INTO EVENING WL PRODUCE LCLLY HIGHER WINDS AND SEAS NR
THE CST.
FRI-MON...NORTHERLY FLOW DAYBREAK FRIDAY MORNING QUICKLY VEERS NE
INTO THE AFTERNOON AND SOUTHEAST DURING THE OVERNIGHT HOURS. BRIEF
PUSH OF SPEEDS UP TO 15KTS WITH NE WIND SHIFT FRI
MORNING...OTHERWISE SPEEDS GENERALLY AROUND 10KTS.
INCREASING S/SW WINDS ON SATURDAY AS NEXT SYSTEM MOVES BY TO THE
NORTH WITH OVERALL SPEEDS AROUND 15KTS WITH 15-20KTS AT TIMES
TOWARDS LATE DAY OVER THE OFFSHORE WATERS. QUICK OFFSHORE MOVING
THUNDERSTORMS WILL BE A POSSIBILITY DURING THE AFTERNOON AND EVENING
HOURS.
WESTERLY WINDS WILL INCREASE 15-20 KNOTS ON SUNDAY WITH ANOTHER
ROUND OF SCATTERED SHOWERS/TSTMS MOVING QUICKLY EASTWARD ACROSS THE
WATERS.
FRONT DROPS INTO REGION ON MONDAY DISRUPTING STRONGER WEST FLOW WITH
WINDS VEERING NORTHWEST 5-10KTS...BECOMING VARIABLE INTO THE
AFTERNOON AS SURFACE HIGH NOSES IN FROM NORTHWEST.
SEAS 2-4FT THROUGH THE PERIOD WITH UP TO 5FT OFFSHORE AT TIMES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 86 66 82 68 / 30 20 10 10
MCO 89 69 88 69 / 40 30 10 10
MLB 86 70 84 72 / 50 40 10 10
VRB 86 68 84 71 / 50 40 20 10
LEE 86 69 87 71 / 40 20 10 10
SFB 87 69 86 70 / 40 30 10 10
ORL 88 70 87 70 / 40 30 10 10
FPR 86 68 84 69 / 50 40 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...PENDERGRAST
LONG TERM....MOSES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1012 PM CDT FRI APR 24 2015
.UPDATE...
736 PM...EVENING UPDATE...BUMPED POPS UP QUITE A BIT FOR THIS
EVENING. UPPER WAVE MOVING ACROSS THE AREA PRODUCING CONVECTIVE
SHOWERS WITH SOME EMBEDDED LIGHTNING NEAR THE QUAD CITIES.
INSTABILITY ALOFT SHOULD WEAKEN AS THIS WAVE SHIFTS EAST...BUT DID
ADD A SLIGHT CHANCE OF THUNDER ACROSS THE SOUTHWEST CWA THRU MID
EVENING. WHILE THE LOW LEVELS REMAIN DRY INITIALLY...RAINFALL IS
SUFFICIENT TO MOISTEN THE LOW LEVELS WITH DEWPOINTS RISING THRU
THE 30S ACROSS NORTHWEST IL AND RFD MEASURED 0.14 OF RAIN THRU
00Z. HOWEVER...THE DRY LOW LEVELS COULD LEAD TO SOME BRIEF/MIXED
SLEET AT ONSET. HRRR HAS BEEN HANDLING THIS WAVE AND ITS
ASSOCIATED PRECIP QUITE WELL AND SHOWS PRECIP SHIFTING EAST OF THE
AREA BY LATE EVENING SO TRENDED POPS BACK LOWER TOWARD MIDNIGHT.
THEN RAIN CHANCES INCREASE IN THE PREDAWN HOURS INTO SATURDAY
MORNING AS THE MAIN LOW ARRIVES AND MADE NO CHANGES TO THIS TIME
PERIOD.
TEMPS HAVE ALREADY DROPPED INTO THE LOWER/MID 40S WHERE RAIN IS
FALLING AND WILL LIKELY NEED TO MAKE SOME DOWNWARD ADJUSTMENTS TO
TEMPS FOR TONIGHT...ESPECIALLY NORTH OF I-80. CMS
&&
.SHORT TERM...
323 PM CDT
THROUGH SATURDAY NIGHT...
SHORT TERM...THROUGH SATURDAY NIGHT...
PRIMARY FORECAST CONCERN IS WITH FAIRLY STRONG LOW PRESSURE
SYSTEM TRACKING SOUTH OF THE AREA ON SATURDAY AND ASSOCIATED RAIN
AND AMOUNTS.
DRY AIR MASS REMAINS OVER THE AREA THIS AFTERNOON...BUT WITH
GRADUAL MOISTENING FROM BONE DRY CONDITIONS EARLIER TODAY THAT
WERE AMONGST DRIEST IN ENTIRE COUNTRY. W/V IMAGERY SHOWS SHORT
WAVE/MIDLEVEL SPEED MAX INTO EASTERN IA THAT IS RESULTING IN
OCCASIONAL VERY LIGHT RAIN/SPRINKLES REACHING THE GROUND DESPITE
LARGE DEWPOINT DEPRESSIONS. SUSPECT THAT HRRR MODEL IS TOO
AGGRESSIVE WITH HIGHER REFLECTIVITY/RAIN REACHING THE GROUND SOUTH
OF I-88 OR SO AND FOCUS FOR MOST ISOLATED TO SCATTERED ACTIVITY
SHOULD BE IN FAR NORTHERN CWA.
LATER THIS EVENING INTO THE OVERNIGHT...AREA WILL BE IN BROAD
WARM ADVECTION ALOFT BUT ALSO LACKING FOCUS FOR PRECIP WITH
MIDLEVEL RIDGING OVERHEAD. SUSPECT THAT THERE WILL BE SEVERAL
MAINLY DRY HOURS WITH PERHAPS A FEW ISOLATED SHOWERS. THEN MAIN
WAVE WILL START TO SPREAD IN FROM SOUTHWEST AFTER MIDNIGHT INTO
SATURDAY MORNING AS CLOSED LOW AND ASSOCIATED SFC LOW MIGRATES
ACROSS LOWER MO VALLEY. PRECIP WILL BE FIGHTING DRY EASTERLY LOW
LEVEL FLOW ESPECIALLY IN NORTHEAST CWA...BUT THEN AS 700 MB FGEN
STRENGTHENS AND TROWAL LIKE FEATURE SPREADS ~1 TO ~1.25 INCH PWATS
ACROSS AREA...EXPECTING MID-LATE SATURDAY AM TO BE ACCOMPANIED BY
PERIODS OF RAIN/RAIN SHOWERS AND STEADY TO EVEN BRIEFLY HEAVY
RATES. VERY MINIMAL ELEVATED INSTABILITY WILL BE PRESENT WELL
SOUTH OF I-80...SO HAVE MAINTAINED SLIGHT EMBEDDED THUNDER CHANCES
THERE. STILL HAVE HIGH END LIKELY TO CAT POPS IN LATE
AFTERNOON...BUT DRIER AIR WORKING IN FROM NORTH SHOULD REDUCE
RATES...WITH PRECIP QUICKLY SHIFTING SOUTH DURING EVENING AND
SKIES CLEARING TOWARD EARLY SUNDAY.
RAIN AMOUNTS FROM MAIN SYSTEM LATE TONIGHT THROUGH SATURDAY
SHOULD RANGE FROM ABOUT 1/2 INCH IN FAR NORTHEAST TO A BIT UPWARDS
OF ONE INCH IN SOUTHWEST 1/4 TO 1/3 OF CWA. CONFIDENCE IN LOW-
MEDIUM IN THESE AMOUNTS GIVEN POTENTIAL FOR BANDING PLACEMENT TO
SHIFT.
REGARDING TEMPS...INCREASING CLOUDS WILL LIMIT FALL TONIGHT...SO
GENERALLY IN 40S TONIGHT EXCEPT UPPER 30S NEAR LAKE COUNTY SHORE.
CLOUDS...RAIN AND GUSTY NORTHEAST FLOW WILL MAKE FOR RAW
CONDITIONS ON SATURDAY AND HIGHS ONLY RECOVERING TO THE LOW/MID
40S TO LOWER 50S...COOLEST ON ILLINOIS SHORE AND WARMEST SOUTH OF
I-80. TEMPS WILL THEN DIP BACK TO THE 30S BY EARLY SUNDAY WITH H8
TEMPS FALLING TO JUST BELOW 0 CELSIUS. EXPECTING SOME NORTHERN
INTERIOR LOCATIONS TO DIP TO AROUND FREEZING. OVERALL IT WILL BE
ANOTHER NIGHT TO PROTECT COLD SENSITIVE VEGETATION.
RC
&&
.LONG TERM...
333 PM CDT
SUNDAY THROUGH FRIDAY...
EXTENDED PERIOD THROUGH AT LEAST THURSDAY WILL BE DOMINATED BY
ONSHORE FLOW AND COOLER CONDITIONS NEAR THE LAKE...BUT ALSO
GRADUAL WARMING INLAND. WITH POSSIBLY MINOR EXCEPTION OF
WEDNESDAY...CONDITIONS SHOULD BE PRIMARILY DRY AS WELL. AIRMASS
WILL BE COOLEST SUNDAY THROUGH EARLY MONDAY...WITH ONLY MID-UPPER
40S ALONG SHORE AND MID-UPPER 50S INLAND AND THEN OVERNIGHT LOWS
SUNDAY NIGHT AWAY FROM CHICAGO HEAT ISLAND IN LOWER-MID 30S. AS
HIGH PRESSURE DROPS SOUTHEAST TOWARD EARLY MONDAY...WINDS MAY
DIMINISH ENOUGH TO SUPPORT AT LEAST PATCHY FROST...BUT HAVE NOT
ADDED IT TO GRIDS YET. INLAND HIGHS SHOULD BE INTO THE 60S EACH
DAY MON-THU AND TEMPS COULD APPROACH 70 NEXT FRIDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* EAST WINDS 10-15 KT BECOMING GUSTY TO 20+ KTS LATE TONIGHT AND
SATURDAY. WINDS SHIFT NORTHEAST SATURDAY EVENING.
* RELATIVELY NARROW W-E AREA OF RAIN CID-DKB-CHI SHOULD DIMINISH
BY 08-10Z. CIGS MAINLY VFR. BRIEF MVFR VIS POSSIBLE IN STEADIER
RAIN.
* STEADY RAIN DEVELOPING MID-LATE MORNING SATURDAY WITH CONDITIONS
DETERIORATING TO IFR BY MIDDAY. IFR LIKELY TO PERSIST THROUGH
MUCH OF THE DAY...WITH FAIRLY QUICK IMPROVEMENT TO MVFR/VFR
DURING SATURDAY EVENING.
RATZER
//DISCUSSION...UPDATED 00Z...
LOW PRESSURE DEVELOPING OVER WESTERN KANSAS EARLY THIS EVENING
WILL MOVE EAST ACROSS NORTHERN MISSOURI AND INTO DOWNSTATE
ILLINOIS THROUGH SATURDAY. DRY EASTERLY FLOW FROM RETREATING HIGH
PRESSURE OVER THE GREAT LAKES REGION WILL HELP TO SLOW THE ADVANCE
OF WIDESPREAD PRECIPITATION TONIGHT AS A LEAD MID-LEVEL
DISTURBANCE LIFTS ACROSS THE AREA...THOUGH THE COLUMN IS EXPECTED
TO SATURATE AS THE MAIN LOW AND MID-LEVEL TROUGH MOVE ACROSS THE
REGION SATURDAY. LIGHT RAIN/SHOWERS OVER NORTHWEST AND NORTH
CENTRAL ILLINOIS WILL EXPERIENCE SOME EROSION AS THEY WORK INTO
NORTHEAST IL THIS EVENING...WITH A LULL IN FORCING LEADING TO ONLY
ISOLATED/WIDELY SCATTERED RAIN LATER TONIGHT. STEADY RAIN WILL
OVERSPREAD THE REGION SATURDAY MORNING HOWEVER...WITH CONDITIONS
EXPECTED TO QUICKLY DETERIORATE TO IFR. RAIN/IFR CIGS AND IFR/MVFR
VIS TO LINGER THROUGH THE DAY...BEFORE WINDS SHIFT TO MORE NORTH-
NORTHEASTERLY IN LOW LEVELS SATURDAY EVENING AND PULL DRIER AIR
INTO THE AREA AS THE LOW SLIDES OFF ACROSS THE OHIO VALLEY.
AHEAD AND NORTH OF THE LOW TRACK...CURRENT NORTHEAST WINDS WILL
GRADUALLY INCREASE AND BECOME MORE EASTERLY OVERNIGHT. SUSTAINED
EAST WINDS 15-20 KTS DURING THE DAY SATURDAY WILL LIKELY BE A
LITTLE GUSTY AS WELL...THOUGH SHALLOW NATURE OF COOL SURFACE
MIXED LAYER MAY LIMIT GUST MAGNITUDE. WINDS SHIFT NORTHEAST
SATURDAY EVENING...AND MAY REMAIN GUSTY 20+ KTS INTO THE NIGHT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH IN RAIN WITH VFR CIGS/BRIEF MVFR VIS INTO OVERNIGHT.
* MEDIUM-HIGH IN WIND DETAILS. LEAST CONFIDENT IN GUST SPEEDS
SATURDAY AFTERNOON/EVENING.
* HIGH IN IFR CONDITIONS IN RAIN SATURDAY. MEDIUM CONFIDENCE IN
TIMING ONSET AND EVENTUAL IMPROVEMENT.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. GUSTY NORTH-NORTHEAST WINDS 20-25 KTS.
MONDAY...VFR. NORTHEAST WINDS.
TUESDAY...VFR. NORTHEAST WINDS BECOMING EAST.
WEDNESDAY...SLGT CHC -RA. BRIEF MVFR POSSIBLE. NORTH-NORTHWEST
WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
RATZER
&&
.MARINE...
215 PM CDT
HIGH PRESSURE MOVING ACROSS THE CENTRAL GREAT LAKES REGION HAS SET
UP GENERALLY LIGHT AND VARIABLE WINDS OVER LAKE MICHIGAN. THE
LIGHT WINDS REGIME AND LAND-LAKE DIFFERENTIAL HEATING HAS SET UP A
LAKE BREEZE WITH NEARSHORE WINDS TAKING AN ONSHORE ORIENTATION
THIS AFTERNOON. AS THE HIGH MOVES OFF TO THE EAST TONIGHT...LOW
PRESSURE OVER THE CENTRAL PLAINS WILL DEEPEN AND MOVE EAST TO NWRN
MO OVERNIGHT TONIGHT. A DEVELOPING WARM FRONT WILL EXTEND EAST
FROM THE LOW ACROSS CNTRL IL/IN...WITH WINDS BECOMING EASTERLY BY
LATE TONIGHT. THE WARM FRONT IS EXPECTED TO REMAIN NEARLY
STATIONARY AS THE LOW TRACKS EWD...KEEPING WINDS OVER THE LAKE
ELY. AS THE LOW PASSES SOUTH OF THE LAKE AND A RIDGE OF HIGH
PRESSURE BUILDS FROM HUDSON BAY THROUGH THE NRN GREAT LAKES...WIND
SPEEDS WILL INCREASE WITH THE STRONGEST WINDS OF 25-30 KT OVER THE
SRN PORTIONS OF THE LAKE. AS THE LOW PASSES EAST THROUGH THE OHIO
VALLEY SATURDAY NIGHT INTO SUNDAY MORNING...WINDS WILL BACK TO
NORTHERLY. WHILE GALES ARE NOT LIKELY...WINDS OVER THE SRN
PORTIONS OF THE LAKE WILL BE STRONG ENOUGH TO REQUIRE A SMALL
CRAFT ADVISORY AND EVEN THOUGH WINDS SHOULD WEAKEN BELOW SMALL
CRAFT ADVISORY LEVELS WITH THE SHIFT TO NORTHERLY...THE LONG FETCH
SHOULD BE SUFFICIENT TO KEEP SMALL CRAFT ADVISORY LEVEL WAVES INTO
MONDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE LAKE BY
TUESDAY MORNING AND REMAIN THE DOMINANT FEATURE THROUGH MUCH OF
NEXT WEEK...SETTING A PERIOD OF RELATIVELY QUIET CONDITIONS OVER
THE LAKE FROM TUESDAY THROUGH THE END OF THE FORECAST PERIOD.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
736 PM CDT FRI APR 24 2015
.UPDATE...
736 PM...EVENING UPDATE...BUMPED POPS UP QUITE A BIT FOR THIS
EVENING. UPPER WAVE MOVING ACROSS THE AREA PRODUCING CONVECTIVE
SHOWERS WITH SOME EMBEDDED LIGHTNING NEAR THE QUAD CITIES.
INSTABILITY ALOFT SHOULD WEAKEN AS THIS WAVE SHIFTS EAST...BUT DID
ADD A SLIGHT CHANCE OF THUNDER ACROSS THE SOUTHWEST CWA THRU MID
EVENING. WHILE THE LOW LEVELS REMAIN DRY INITIALLY...RAINFALL IS
SUFFICIENT TO MOISTEN THE LOW LEVELS WITH DEWPOINTS RISING THRU
THE 30S ACROSS NORTHWEST IL AND RFD MEASURED 0.14 OF RAIN THRU
00Z. HOWEVER...THE DRY LOW LEVELS COULD LEAD TO SOME BRIEF/MIXED
SLEET AT ONSET. HRRR HAS BEEN HANDLING THIS WAVE AND ITS
ASSOCIATED PRECIP QUITE WELL AND SHOWS PRECIP SHIFTING EAST OF THE
AREA BY LATE EVENING SO TRENDED POPS BACK LOWER TOWARD MIDNIGHT.
THEN RAIN CHANCES INCREASE IN THE PREDAWN HOURS INTO SATURDAY
MORNING AS THE MAIN LOW ARRIVES AND MADE NO CHANGES TO THIS TIME
PERIOD.
TEMPS HAVE ALREADY DROPPED INTO THE LOWER/MID 40S WHERE RAIN IS
FALLING AND WILL LIKELY NEED TO MAKE SOME DOWNWARD ADJUSTMENTS TO
TEMPS FOR TONIGHT...ESPECIALLY NORTH OF I-80. CMS
&&
.SHORT TERM...
323 PM CDT
THROUGH SATURDAY NIGHT...
SHORT TERM...THROUGH SATURDAY NIGHT...
PRIMARY FORECAST CONCERN IS WITH FAIRLY STRONG LOW PRESSURE
SYSTEM TRACKING SOUTH OF THE AREA ON SATURDAY AND ASSOCIATED RAIN
AND AMOUNTS.
DRY AIR MASS REMAINS OVER THE AREA THIS AFTERNOON...BUT WITH
GRADUAL MOISTENING FROM BONE DRY CONDITIONS EARLIER TODAY THAT
WERE AMONGST DRIEST IN ENTIRE COUNTRY. W/V IMAGERY SHOWS SHORT
WAVE/MIDLEVEL SPEED MAX INTO EASTERN IA THAT IS RESULTING IN
OCCASIONAL VERY LIGHT RAIN/SPRINKLES REACHING THE GROUND DESPITE
LARGE DEWPOINT DEPRESSIONS. SUSPECT THAT HRRR MODEL IS TOO
AGGRESSIVE WITH HIGHER REFLECTIVITY/RAIN REACHING THE GROUND SOUTH
OF I-88 OR SO AND FOCUS FOR MOST ISOLATED TO SCATTERED ACTIVITY
SHOULD BE IN FAR NORTHERN CWA.
LATER THIS EVENING INTO THE OVERNIGHT...AREA WILL BE IN BROAD
WARM ADVECTION ALOFT BUT ALSO LACKING FOCUS FOR PRECIP WITH
MIDLEVEL RIDGING OVERHEAD. SUSPECT THAT THERE WILL BE SEVERAL
MAINLY DRY HOURS WITH PERHAPS A FEW ISOLATED SHOWERS. THEN MAIN
WAVE WILL START TO SPREAD IN FROM SOUTHWEST AFTER MIDNIGHT INTO
SATURDAY MORNING AS CLOSED LOW AND ASSOCIATED SFC LOW MIGRATES
ACROSS LOWER MO VALLEY. PRECIP WILL BE FIGHTING DRY EASTERLY LOW
LEVEL FLOW ESPECIALLY IN NORTHEAST CWA...BUT THEN AS 700 MB FGEN
STRENGTHENS AND TROWAL LIKE FEATURE SPREADS ~1 TO ~1.25 INCH PWATS
ACROSS AREA...EXPECTING MID-LATE SATURDAY AM TO BE ACCOMPANIED BY
PERIODS OF RAIN/RAIN SHOWERS AND STEADY TO EVEN BRIEFLY HEAVY
RATES. VERY MINIMAL ELEVATED INSTABILITY WILL BE PRESENT WELL
SOUTH OF I-80...SO HAVE MAINTAINED SLIGHT EMBEDDED THUNDER CHANCES
THERE. STILL HAVE HIGH END LIKELY TO CAT POPS IN LATE
AFTERNOON...BUT DRIER AIR WORKING IN FROM NORTH SHOULD REDUCE
RATES...WITH PRECIP QUICKLY SHIFTING SOUTH DURING EVENING AND
SKIES CLEARING TOWARD EARLY SUNDAY.
RAIN AMOUNTS FROM MAIN SYSTEM LATE TONIGHT THROUGH SATURDAY
SHOULD RANGE FROM ABOUT 1/2 INCH IN FAR NORTHEAST TO A BIT UPWARDS
OF ONE INCH IN SOUTHWEST 1/4 TO 1/3 OF CWA. CONFIDENCE IN LOW-
MEDIUM IN THESE AMOUNTS GIVEN POTENTIAL FOR BANDING PLACEMENT TO
SHIFT.
REGARDING TEMPS...INCREASING CLOUDS WILL LIMIT FALL TONIGHT...SO
GENERALLY IN 40S TONIGHT EXCEPT UPPER 30S NEAR LAKE COUNTY SHORE.
CLOUDS...RAIN AND GUSTY NORTHEAST FLOW WILL MAKE FOR RAW
CONDITIONS ON SATURDAY AND HIGHS ONLY RECOVERING TO THE LOW/MID
40S TO LOWER 50S...COOLEST ON ILLINOIS SHORE AND WARMEST SOUTH OF
I-80. TEMPS WILL THEN DIP BACK TO THE 30S BY EARLY SUNDAY WITH H8
TEMPS FALLING TO JUST BELOW 0 CELSIUS. EXPECTING SOME NORTHERN
INTERIOR LOCATIONS TO DIP TO AROUND FREEZING. OVERALL IT WILL BE
ANOTHER NIGHT TO PROTECT COLD SENSITIVE VEGETATION.
RC
&&
.LONG TERM...
333 PM CDT
SUNDAY THROUGH FRIDAY...
EXTENDED PERIOD THROUGH AT LEAST THURSDAY WILL BE DOMINATED BY
ONSHORE FLOW AND COOLER CONDITIONS NEAR THE LAKE...BUT ALSO
GRADUAL WARMING INLAND. WITH POSSIBLY MINOR EXCEPTION OF
WEDNESDAY...CONDITIONS SHOULD BE PRIMARILY DRY AS WELL. AIRMASS
WILL BE COOLEST SUNDAY THROUGH EARLY MONDAY...WITH ONLY MID-UPPER
40S ALONG SHORE AND MID-UPPER 50S INLAND AND THEN OVERNIGHT LOWS
SUNDAY NIGHT AWAY FROM CHICAGO HEAT ISLAND IN LOWER-MID 30S. AS
HIGH PRESSURE DROPS SOUTHEAST TOWARD EARLY MONDAY...WINDS MAY
DIMINISH ENOUGH TO SUPPORT AT LEAST PATCHY FROST...BUT HAVE NOT
ADDED IT TO GRIDS YET. INLAND HIGHS SHOULD BE INTO THE 60S EACH
DAY MON-THU AND TEMPS COULD APPROACH 70 NEXT FRIDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* EAST-NORTHEAST WINDS 10-15 KT THIS EVENING BECOMING EAST AND
INCREASINGLY GUSTY LATE TONIGHT AND SATURDAY. WINDS SHIFT
NORTHEAST SATURDAY EVENING.
* AREA OF LIGHT RAIN/SHOWERS THIS EVENING...HEAVIEST
NORTH/NORTHWEST OF CHICAGO. SCATTERED/ISOLATED SHOWERS
OVERNIGHT.
* STEADY RAIN DEVELOPING MID-LATE MORNING SATURDAY WITH CONDITIONS
DETERIORATING TO IFR BY MIDDAY. IFR LIKELY TO PERSIST THROUGH
MUCH OF THE DAY...WITH FAIRLY QUICK IMPROVEMENT TO MVFR/VFR
DURING SATURDAY EVENING.
RATZER
//DISCUSSION...UPDATED 00Z...
LOW PRESSURE DEVELOPING OVER WESTERN KANSAS EARLY THIS EVENING
WILL MOVE EAST ACROSS NORTHERN MISSOURI AND INTO DOWNSTATE
ILLINOIS THROUGH SATURDAY. DRY EASTERLY FLOW FROM RETREATING HIGH
PRESSURE OVER THE GREAT LAKES REGION WILL HELP TO SLOW THE ADVANCE
OF WIDESPREAD PRECIPITATION TONIGHT AS A LEAD MID-LEVEL
DISTURBANCE LIFTS ACROSS THE AREA...THOUGH THE COLUMN IS EXPECTED
TO SATURATE AS THE MAIN LOW AND MID-LEVEL TROUGH MOVE ACROSS THE
REGION SATURDAY. LIGHT RAIN/SHOWERS OVER NORTHWEST AND NORTH
CENTRAL ILLINOIS WILL EXPERIENCE SOME EROSION AS THEY WORK INTO
NORTHEAST IL THIS EVENING...WITH A LULL IN FORCING LEADING TO ONLY
ISOLATED/WIDELY SCATTERED RAIN LATER TONIGHT. STEADY RAIN WILL
OVERSPREAD THE REGION SATURDAY MORNING HOWEVER...WITH CONDITIONS
EXPECTED TO QUICKLY DETERIORATE TO IFR. RAIN/IFR CIGS AND IFR/MVFR
VIS TO LINGER THROUGH THE DAY...BEFORE WINDS SHIFT TO MORE NORTH-
NORTHEASTERLY IN LOW LEVELS SATURDAY EVENING AND PULL DRIER AIR
INTO THE AREA AS THE LOW SLIDES OFF ACROSS THE OHIO VALLEY.
AHEAD AND NORTH OF THE LOW TRACK...CURRENT NORTHEAST WINDS WILL
GRADUALLY INCREASE AND BECOME MORE EASTERLY OVERNIGHT. SUSTAINED
EAST WINDS 15-20 KTS DURING THE DAY SATURDAY WILL LIKELY BE A
LITTLE GUSTY AS WELL...THOUGH SHALLOW NATURE OF COOL SURFACE
MIXED LAYER MAY LIMIT GUST MAGNITUDE. WINDS SHIFT NORTHEAST
SATURDAY EVENING...AND MAY REMAIN GUSTY 20+ KTS INTO THE NIGHT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH IN MAINLY VFR LIGHT RAIN/SHOWERS THIS EVENING.
* MEDIUM-HIGH IN WIND DETAILS. LEAST CONFIDENT IN GUST SPEEDS
SATURDAY AFTERNOON/EVENING.
* HIGH IN IFR CONDITIONS IN RAIN SATURDAY. MEDIUM CONFIDENCE IN
TIMING ONSET AND EVENTUAL IMPROVEMENT.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. GUSTY NORTH-NORTHEAST WINDS 20-25 KTS.
MONDAY...VFR. NORTHEAST WINDS.
TUESDAY...VFR. NORTHEAST WINDS BECOMING EAST.
WEDNESDAY...SLGT CHC -RA. BRIEF MVFR POSSIBLE. NORTH-NORTHWEST
WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
RATZER
&&
.MARINE...
215 PM CDT
HIGH PRESSURE MOVING ACROSS THE CENTRAL GREAT LAKES REGION HAS SET
UP GENERALLY LIGHT AND VARIABLE WINDS OVER LAKE MICHIGAN. THE
LIGHT WINDS REGIME AND LAND-LAKE DIFFERENTIAL HEATING HAS SET UP A
LAKE BREEZE WITH NEARSHORE WINDS TAKING AN ONSHORE ORIENTATION
THIS AFTERNOON. AS THE HIGH MOVES OFF TO THE EAST TONIGHT...LOW
PRESSURE OVER THE CENTRAL PLAINS WILL DEEPEN AND MOVE EAST TO NWRN
MO OVERNIGHT TONIGHT. A DEVELOPING WARM FRONT WILL EXTEND EAST
FROM THE LOW ACROSS CNTRL IL/IN...WITH WINDS BECOMING EASTERLY BY
LATE TONIGHT. THE WARM FRONT IS EXPECTED TO REMAIN NEARLY
STATIONARY AS THE LOW TRACKS EWD...KEEPING WINDS OVER THE LAKE
ELY. AS THE LOW PASSES SOUTH OF THE LAKE AND A RIDGE OF HIGH
PRESSURE BUILDS FROM HUDSON BAY THROUGH THE NRN GREAT LAKES...WIND
SPEEDS WILL INCREASE WITH THE STRONGEST WINDS OF 25-30 KT OVER THE
SRN PORTIONS OF THE LAKE. AS THE LOW PASSES EAST THROUGH THE OHIO
VALLEY SATURDAY NIGHT INTO SUNDAY MORNING...WINDS WILL BACK TO
NORTHERLY. WHILE GALES ARE NOT LIKELY...WINDS OVER THE SRN
PORTIONS OF THE LAKE WILL BE STRONG ENOUGH TO REQUIRE A SMALL
CRAFT ADVISORY AND EVEN THOUGH WINDS SHOULD WEAKEN BELOW SMALL
CRAFT ADVISORY LEVELS WITH THE SHIFT TO NORTHERLY...THE LONG FETCH
SHOULD BE SUFFICIENT TO KEEP SMALL CRAFT ADVISORY LEVEL WAVES INTO
MONDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE LAKE BY
TUESDAY MORNING AND REMAIN THE DOMINANT FEATURE THROUGH MUCH OF
NEXT WEEK...SETTING A PERIOD OF RELATIVELY QUIET CONDITIONS OVER
THE LAKE FROM TUESDAY THROUGH THE END OF THE FORECAST PERIOD.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
659 PM CDT FRI APR 24 2015
.SHORT TERM...
323 PM CDT
THROUGH SATURDAY NIGHT...
SHORT TERM...THROUGH SATURDAY NIGHT...
PRIMARY FORECAST CONCERN IS WITH FAIRLY STRONG LOW PRESSURE
SYSTEM TRACKING SOUTH OF THE AREA ON SATURDAY AND ASSOCIATED RAIN
AND AMOUNTS.
DRY AIR MASS REMAINS OVER THE AREA THIS AFTERNOON...BUT WITH
GRADUAL MOISTENING FROM BONE DRY CONDITIONS EARLIER TODAY THAT
WERE AMONGST DRIEST IN ENTIRE COUNTRY. W/V IMAGERY SHOWS SHORT
WAVE/MIDLEVEL SPEED MAX INTO EASTERN IA THAT IS RESULTING IN
OCCASIONAL VERY LIGHT RAIN/SPRINKLES REACHING THE GROUND DESPITE
LARGE DEWPOINT DEPRESSIONS. SUSPECT THAT HRRR MODEL IS TOO
AGGRESSIVE WITH HIGHER REFLECTIVITY/RAIN REACHING THE GROUND SOUTH
OF I-88 OR SO AND FOCUS FOR MOST ISOLATED TO SCATTERED ACTIVITY
SHOULD BE IN FAR NORTHERN CWA.
LATER THIS EVENING INTO THE OVERNIGHT...AREA WILL BE IN BROAD
WARM ADVECTION ALOFT BUT ALSO LACKING FOCUS FOR PRECIP WITH
MIDLEVEL RIDGING OVERHEAD. SUSPECT THAT THERE WILL BE SEVERAL
MAINLY DRY HOURS WITH PERHAPS A FEW ISOLATED SHOWERS. THEN MAIN
WAVE WILL START TO SPREAD IN FROM SOUTHWEST AFTER MIDNIGHT INTO
SATURDAY MORNING AS CLOSED LOW AND ASSOCIATED SFC LOW MIGRATES
ACROSS LOWER MO VALLEY. PRECIP WILL BE FIGHTING DRY EASTERLY LOW
LEVEL FLOW ESPECIALLY IN NORTHEAST CWA...BUT THEN AS 700 MB FGEN
STRENGTHENS AND TROWAL LIKE FEATURE SPREADS ~1 TO ~1.25 INCH PWATS
ACROSS AREA...EXPECTING MID-LATE SATURDAY AM TO BE ACCOMPANIED BY
PERIODS OF RAIN/RAIN SHOWERS AND STEADY TO EVEN BRIEFLY HEAVY
RATES. VERY MINIMAL ELEVATED INSTABILITY WILL BE PRESENT WELL
SOUTH OF I-80...SO HAVE MAINTAINED SLIGHT EMBEDDED THUNDER CHANCES
THERE. STILL HAVE HIGH END LIKELY TO CAT POPS IN LATE
AFTERNOON...BUT DRIER AIR WORKING IN FROM NORTH SHOULD REDUCE
RATES...WITH PRECIP QUICKLY SHIFTING SOUTH DURING EVENING AND
SKIES CLEARING TOWARD EARLY SUNDAY.
RAIN AMOUNTS FROM MAIN SYSTEM LATE TONIGHT THROUGH SATURDAY
SHOULD RANGE FROM ABOUT 1/2 INCH IN FAR NORTHEAST TO A BIT UPWARDS
OF ONE INCH IN SOUTHWEST 1/4 TO 1/3 OF CWA. CONFIDENCE IN LOW-
MEDIUM IN THESE AMOUNTS GIVEN POTENTIAL FOR BANDING PLACEMENT TO
SHIFT.
REGARDING TEMPS...INCREASING CLOUDS WILL LIMIT FALL TONIGHT...SO
GENERALLY IN 40S TONIGHT EXCEPT UPPER 30S NEAR LAKE COUNTY SHORE.
CLOUDS...RAIN AND GUSTY NORTHEAST FLOW WILL MAKE FOR RAW
CONDITIONS ON SATURDAY AND HIGHS ONLY RECOVERING TO THE LOW/MID
40S TO LOWER 50S...COOLEST ON ILLINOIS SHORE AND WARMEST SOUTH OF
I-80. TEMPS WILL THEN DIP BACK TO THE 30S BY EARLY SUNDAY WITH H8
TEMPS FALLING TO JUST BELOW 0 CELSIUS. EXPECTING SOME NORTHERN
INTERIOR LOCATIONS TO DIP TO AROUND FREEZING. OVERALL IT WILL BE
ANOTHER NIGHT TO PROTECT COLD SENSITIVE VEGETATION.
RC
&&
.LONG TERM...
333 PM CDT
SUNDAY THROUGH FRIDAY...
EXTENDED PERIOD THROUGH AT LEAST THURSDAY WILL BE DOMINATED BY
ONSHORE FLOW AND COOLER CONDITIONS NEAR THE LAKE...BUT ALSO
GRADUAL WARMING INLAND. WITH POSSIBLY MINOR EXCEPTION OF
WEDNESDAY...CONDITIONS SHOULD BE PRIMARILY DRY AS WELL. AIRMASS
WILL BE COOLEST SUNDAY THROUGH EARLY MONDAY...WITH ONLY MID-UPPER
40S ALONG SHORE AND MID-UPPER 50S INLAND AND THEN OVERNIGHT LOWS
SUNDAY NIGHT AWAY FROM CHICAGO HEAT ISLAND IN LOWER-MID 30S. AS
HIGH PRESSURE DROPS SOUTHEAST TOWARD EARLY MONDAY...WINDS MAY
DIMINISH ENOUGH TO SUPPORT AT LEAST PATCHY FROST...BUT HAVE NOT
ADDED IT TO GRIDS YET. INLAND HIGHS SHOULD BE INTO THE 60S EACH
DAY MON-THU AND TEMPS COULD APPROACH 70 NEXT FRIDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* EAST-NORTHEAST WINDS 10-15 KT THIS EVENING BECOMING EAST AND
INCREASINGLY GUSTY LATE TONIGHT AND SATURDAY. WINDS SHIFT
NORTHEAST SATURDAY EVENING.
* AREA OF LIGHT RAIN/SHOWERS THIS EVENING...HEAVIEST
NORTH/NORTHWEST OF CHICAGO. SCATTERED/ISOLATED SHOWERS
OVERNIGHT.
* STEADY RAIN DEVELOPING MID-LATE MORNING SATURDAY WITH CONDITIONS
DETERIORATING TO IFR BY MIDDAY. IFR LIKELY TO PERSIST THROUGH
MUCH OF THE DAY...WITH FAIRLY QUICK IMPROVEMENT TO MVFR/VFR
DURING SATURDAY EVENING.
RATZER
//DISCUSSION...UPDATED 00Z...
LOW PRESSURE DEVELOPING OVER WESTERN KANSAS EARLY THIS EVENING
WILL MOVE EAST ACROSS NORTHERN MISSOURI AND INTO DOWNSTATE
ILLINOIS THROUGH SATURDAY. DRY EASTERLY FLOW FROM RETREATING HIGH
PRESSURE OVER THE GREAT LAKES REGION WILL HELP TO SLOW THE ADVANCE
OF WIDESPREAD PRECIPITATION TONIGHT AS A LEAD MID-LEVEL
DISTURBANCE LIFTS ACROSS THE AREA...THOUGH THE COLUMN IS EXPECTED
TO SATURATE AS THE MAIN LOW AND MID-LEVEL TROUGH MOVE ACROSS THE
REGION SATURDAY. LIGHT RAIN/SHOWERS OVER NORTHWEST AND NORTH
CENTRAL ILLINOIS WILL EXPERIENCE SOME EROSION AS THEY WORK INTO
NORTHEAST IL THIS EVENING...WITH A LULL IN FORCING LEADING TO ONLY
ISOLATED/WIDELY SCATTERED RAIN LATER TONIGHT. STEADY RAIN WILL
OVERSPREAD THE REGION SATURDAY MORNING HOWEVER...WITH CONDITIONS
EXPECTED TO QUICKLY DETERIORATE TO IFR. RAIN/IFR CIGS AND IFR/MVFR
VIS TO LINGER THROUGH THE DAY...BEFORE WINDS SHIFT TO MORE NORTH-
NORTHEASTERLY IN LOW LEVELS SATURDAY EVENING AND PULL DRIER AIR
INTO THE AREA AS THE LOW SLIDES OFF ACROSS THE OHIO VALLEY.
AHEAD AND NORTH OF THE LOW TRACK...CURRENT NORTHEAST WINDS WILL
GRADUALLY INCREASE AND BECOME MORE EASTERLY OVERNIGHT. SUSTAINED
EAST WINDS 15-20 KTS DURING THE DAY SATURDAY WILL LIKELY BE A
LITTLE GUSTY AS WELL...THOUGH SHALLOW NATURE OF COOL SURFACE
MIXED LAYER MAY LIMIT GUST MAGNITUDE. WINDS SHIFT NORTHEAST
SATURDAY EVENING...AND MAY REMAIN GUSTY 20+ KTS INTO THE NIGHT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH IN MAINLY VFR LIGHT RAIN/SHOWERS THIS EVENING.
* MEDIUM-HIGH IN WIND DETAILS. LEAST CONFIDENT IN GUST SPEEDS
SATURDAY AFTERNOON/EVENING.
* HIGH IN IFR CONDITIONS IN RAIN SATURDAY. MEDIUM CONFIDENCE IN
TIMING ONSET AND EVENTUAL IMPROVEMENT.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. GUSTY NORTH-NORTHEAST WINDS 20-25 KTS.
MONDAY...VFR. NORTHEAST WINDS.
TUESDAY...VFR. NORTHEAST WINDS BECOMING EAST.
WEDNESDAY...SLGT CHC -RA. BRIEF MVFR POSSIBLE. NORTH-NORTHWEST
WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
RATZER
&&
.MARINE...
215 PM CDT
HIGH PRESSURE MOVING ACROSS THE CENTRAL GREAT LAKES REGION HAS SET
UP GENERALLY LIGHT AND VARIABLE WINDS OVER LAKE MICHIGAN. THE
LIGHT WINDS REGIME AND LAND-LAKE DIFFERENTIAL HEATING HAS SET UP A
LAKE BREEZE WITH NEARSHORE WINDS TAKING AN ONSHORE ORIENTATION
THIS AFTERNOON. AS THE HIGH MOVES OFF TO THE EAST TONIGHT...LOW
PRESSURE OVER THE CENTRAL PLAINS WILL DEEPEN AND MOVE EAST TO NWRN
MO OVERNIGHT TONIGHT. A DEVELOPING WARM FRONT WILL EXTEND EAST
FROM THE LOW ACROSS CNTRL IL/IN...WITH WINDS BECOMING EASTERLY BY
LATE TONIGHT. THE WARM FRONT IS EXPECTED TO REMAIN NEARLY
STATIONARY AS THE LOW TRACKS EWD...KEEPING WINDS OVER THE LAKE
ELY. AS THE LOW PASSES SOUTH OF THE LAKE AND A RIDGE OF HIGH
PRESSURE BUILDS FROM HUDSON BAY THROUGH THE NRN GREAT LAKES...WIND
SPEEDS WILL INCREASE WITH THE STRONGEST WINDS OF 25-30 KT OVER THE
SRN PORTIONS OF THE LAKE. AS THE LOW PASSES EAST THROUGH THE OHIO
VALLEY SATURDAY NIGHT INTO SUNDAY MORNING...WINDS WILL BACK TO
NORTHERLY. WHILE GALES ARE NOT LIKELY...WINDS OVER THE SRN
PORTIONS OF THE LAKE WILL BE STRONG ENOUGH TO REQUIRE A SMALL
CRAFT ADVISORY AND EVEN THOUGH WINDS SHOULD WEAKEN BELOW SMALL
CRAFT ADVISORY LEVELS WITH THE SHIFT TO NORTHERLY...THE LONG FETCH
SHOULD BE SUFFICIENT TO KEEP SMALL CRAFT ADVISORY LEVEL WAVES INTO
MONDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE LAKE BY
TUESDAY MORNING AND REMAIN THE DOMINANT FEATURE THROUGH MUCH OF
NEXT WEEK...SETTING A PERIOD OF RELATIVELY QUIET CONDITIONS OVER
THE LAKE FROM TUESDAY THROUGH THE END OF THE FORECAST PERIOD.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
107 AM CDT THU APR 23 2015
.UPDATE...826 PM CDT
FOR EVENING UPDATE...
LOWERED OVERNIGHT MINS A BIT ESPECIALLY IN THE ROCK/FOX RIVER
VALLEYS WEST OF CHICAGO. CLEARING SKIES...DECOUPLING WINDS AND VERY
DRY LOW LEVEL AIR IS EXPECTED TO RESULT IN SUB-FREEZING TEMPS
OVERNIGHT AWAY FROM THE URBAN CORE OF CHICAGO.
THE FORECAST AREA REMAINS UNDER THE INFLUENCE OF LARGE UPPER TROUGH
ACROSS EASTERN NORTH AMERICA...AND SURFACE LOW PRESSURE SLOWLY
MOVING FROM NORTHEAST OF THE GREAT LAKES TOWARD NEW ENGLAND AND
SOUTHERN QUEBEC. COLD AIR ON BLUSTERY WEST-NORTHWEST WINDS AND
EXTENSIVE CLOSED-CELL STRATOCU HAD EARLIER RESULTED IN AFTERNOON
TEMPERATURES STRUGGLING TO RISE OUT OF THE 40S IN MOST AREAS...WITH
EVEN A FEW SNOW FLURRIES NOTED THANKS TO A COMBINATION OF COLD AIR
ALOFT (-5C AT 850 MB PER 21Z AMDAR ASCENT SOUNDING FROM MDW)...STEEP
BOUNDARY LAYER LAPSE RATES AND LOW WET-BULB ZERO HEIGHTS OF 500-1000
FEET.
CURRENT IR SATELLITE IMAGERY SHOWS WESTERN/SOUTHERN PERIPHERY OF THE
CLOUD SHIELD ERODING WITH LOSS OF DIURNAL SURFACE-BASED INSTABILITY
THOUGH PATCHY CLOUD COVER WILL LIKELY CONTINUE TO AFFECT PARTS OF
NORTHEAST IL/NORTHWEST INDIANA INTO THE NIGHT BENEATH SHEARED AND
ELONGATED MID-LEVEL VORTICITY CHANNEL...THOUGH EVEN THOSE AREAS WILL
LIKELY SEE CLOUDS SCATTER OVERNIGHT PER RAP RH PROGS. AS INDICATED
ABOVE...CLEARING SKIES AND DECREASING WINDS COMBINED WITH DRY LOW
LEVEL AIR MASS (SURFACE DEW POINTS TEENS-LOW 20S OVER NORTH CENTRAL
IL) WILL ALLOW TEMPS TO SINK INTO THE MID 20S AWAY FROM THE CITY
OVERNIGHT...POSSIBLY EVEN LOWER 20S IN SOME SHELTERED SPOTS WHERE
WINDS ABLE TO DECOUPLE MORE STRONGLY IN MODEST SFC PRESSURE
GRADIENT. EXPECT DEW POINT TEMPS ACROSS EASTERN IA...CURRENTLY IN
THE SINGLE DIGITS IN SOME SPOTS...WILL COME UP A LITTLE WITH LOSS OF
DEEPER MIXING AND DECREASE IN WINDS. OTHERWISE...COULD SEE NEEDING
TO LOWER MIN TEMPS EVEN MORE ESPECIALLY WEST OF THE FOX RIVER.
RATZER
&&
.SHORT TERM...
315 PM CDT
THROUGH FRIDAY...
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH THE BELOW NORMAL TEMPS
TO PERSIST AND WITH WELL BELOW NORMAL TEMPS AROUND OR BELOW
FREEZING TONIGHT AND THURSDAY NIGHT...WITH A FREEZE WARNING IN
EFFECT FOR THE ENTIRE CWA TONIGHT.
WITH THE LARGE UPPER LEVEL LOW STILL SPINNING JUST NORTHEAST OF
THE GREAT LAKES REGION...FAIRLY ENERGETIC FLOW CONTINUES TO MOVE
OVERHEAD. THIS COINCIDING WITH STEEP LOW LEVEL LAPSE RATES ACROSS
NORTHERN ILLINOIS AND NORTHWEST INDIANA...ISOLATED SHOWERY
ACTIVITY IS STILL ONGOING AT THIS TIME. THIS WILL LIKELY CONTINUE
OVER THE NEXT COUPLE OF HOURS...BEFORE DIMINISHING BY EARLY THIS
EVENING. PRECIP TYPE WILL BE EITHER FLURRIES OR SPRINKLES DURING
THIS TIME. DESPITE LOW TO MID 40 SURFACE TEMPS IN PLACE...VERY
COLD AIR ALOFT AND THESE STEEP LAPSE RATES WILL CONTINUE TO
SUPPORT THE DEVELOPMENT OF FLURRIES AT TIMES. EXTENSIVE CLOUD
COVER STILL IN PLACE THIS AFTERNOON WILL DIMINISH THROUGH THE
EARLY EVENING...WITH CLEARING SKIES EXPECTED THROUGH THE REMAINDER
OF THE EVENING AND OVERNIGHT. WITH THE VERY COLD AIRMASS IN PLACE
AND CLEARING SKIES...VERY CHILLY CONDITIONS WILL OCCUR OVER THE
ENTIRE CWA TONIGHT. HAVE LOWERED TEMPS A COUPLE OF DEGREES IN MOST
PLACES...WITH THE UPPER 20S TO AROUND 30 LIKELY FOR MOST LOCATIONS
AND LOWER 30S FOR THE CHICAGO METRO AREA. WITH THESE EXPECTED
TEMPS...HAVE ISSUED A FREEZE WARNING FOR THE ENTIRE CWA INCLUDING
COOK...FOR AREAS OUTSIDE OF THE IMMEDIATE CITY. THIS WILL START
JUST AFTER THE MIDNIGHT TIME FRAME...GOING THROUGH 13Z THURSDAY.
HAVE MADE MENTION OF PATCHY FROST TONIGHT BUT WITH THE WINDS
STAYING SLIGHTLY ELEVATED...WIDESPREAD FROST DOES NOT APPEAR
LIKELY AT THIS TIME. ANOTHER COLD NIGHT IN THE LOWER 30S IS LIKELY
THURSDAY NIGHT AND WITH HIGH PRESSURE AND LIGHT TO CALM WINDS
SETTLING IN...WIDESPREAD FROST APPEARS MORE LIKELY DURING THIS
TIME.
RODRIGUEZ
&&
.LONG TERM...
315 PM CDT
FRIDAY NIGHT THROUGH WEDNESDAY...
PRECIP CHANCES WILL BEGIN TO INCREASE BY THE START OF THE WEEKEND
AS MID/UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW APPROACH FROM
THE CENTRAL PLAINS. THE ARRIVAL OF THIS SYSTEM AND BEST FORCING
APPEAR TO ARRIVE DURING THE DAY SATURDAY AND LIKELY CONTINUE INTO
THE EVENING. AT THIS TIME IT DOES LOOK LIKE THE ENTIRE CWA WILL
OBSERVE RAIN...BUT SOME GUIDANCE IS HINTING AT A MORE SOUTHERLY
TRACK. SO DID RAISE POPS ON SATURDAY BUT KEPT THE HIGHEST ACROSS
THE SOUTHERN HALF OF THE CWA. WITH THE DEPARTURE OF THIS SYSTEM
AND RAIN...CONDITIONS DRY AND LOOK TO REMAIN DRY THROUGH EARLY
NEXT WEEK...WITH A TREND TOWARDS MORE NORMAL TEMPS.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* GUSTY WEST/NORTHWEST WINDS THURSDAY.
KMD
//DISCUSSION...UPDATED 06Z...
STILL A PRESSURE GRADIENT OVER THE AREA SO SOME LIGHT WNW WINDS
REMAIN IN PLACE. WINDS WILL INCREASE AGAIN THURSDAY MORNING BUT WILL
NOT BE AS STRONG AS WEDNESDAY WITH GUSTS EXPECTED IN THE UPPER
TEENS TO NEAR 20KT RANGE. A LAKE BREEZE IS POSSIBLE...BUT AT THIS
TIME CONFIDENCE ONLY EXISTS IN THE LAKE BREEZE MAKING IT TO THE
NEAR SHORELINE AREAS. WINDS WILL QUICKLY DIMINISH THURSDAY EVENING
AS HIGH PRESSURE MOVES ACROSS THE AREA. KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH FOR WINDS THRU THE PERIOD.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...SLIGHT CHANCE EVENING SHRA. VFR. EAST WINDS.
* SATURDAY...SHRA LIKELY. IFR LIKELY. STRONG/GUSTY NORTHEAST WINDS.
* SUNDAY THRU TUESDAY...DRY/VFR. NORTHEAST WINDS.
&&
.MARINE...
130 PM CDT
UNSEASONABLY STRONG LOW PRESSURE NEAR JAMES BAY CONTINUES TO
RESULT IN FAIRLY STRONG NORTHWEST WINDS ACROSS THE LAKE AND THESE
WINDS SHOULD CONTINUE INTO TONIGHT BEFORE HIGH PRESSURE OVER THE
PLAINS BEGINS TO MIGRATE EASTWARD TOWARD THE MISSISSIPPI VALLEY. A
COUPLE OF DAYS OF FAIRLY LIGHT WINDS DOMINATED BY LAND/LAKE BREEZE
CIRCULATIONS SHOULD ENSUE THURSDAY AND FRIDAY BEFORE ANOTHER
FAIRLY STRONG LOW PRESSURE CAUSES WINDS TO RAMP UP AGAIN FRIDAY
NIGHT AND ESPECIALLY SATURDAY. THIS LOW WILL PASS WELL SOUTH OF
THE LAKE SETTING THE STAGE FOR STRONG NORTHEASTERLY
WINDS...ESPECIALLY SOUTHERN PORTIONS OF THE LAKE WHERE WINDS COULD
END UP NOT TERRIBLY FAR FOR GALE FORCE FOR A TIME SATURDAY
AFTERNOON SHOULD THE STRONGER MODELS VERIFY. NORTHERLY WINDS WILL
BEGIN TO EASE SUNDAY WITH GRADIENT BECOMING FAIRLY WEAK HEADING
INTO NEXT WEEK WITH WINDS ONCE AGAIN PRIMARILY DOMINATED BY
LAKE/LAND BREEZE CIRCULATION.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 8 AM THURSDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8 AM
THURSDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 AM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1130 PM CDT WED APR 22 2015
.SYNOPSIS...
ISSUED AT 305 PM CDT WED APR 22 2015
THE MIDWEST REMAINS UNDER THE INFLUENCE OF A STACKED LOW PRESSURE
SYSTEM CENTERED OVER ONTARIO. THE MAIN SENSIBLE WEATHER IMPACT
ACROSS E IOWA/W ILLINOIS TODAY HAS BEEN THE STRONG/GUSTY NW WINDS
BETWEEN 30-40 MPH. SFC DEWPOINTS ARE VERY LOW...HOVERING IN THE
TEENS. AT 3 PM THE RH AT THE DAVENPORT AIRPORT WAS DOWN TO 18
PERCENT.
&&
.UPDATE...
ISSUED AT 812 PM CDT WED APR 22 2015
CURRENT SURFACE ANALYSIS SHOWS DEWPOINT TEMPERATURES IN THE SINGLE
DIGITS UPSTREAM IN MN. 23Z RAP HAS THESE VALUES ADVECT ACROSS THE
AREA TONIGHT. CURRENT DEWPOINT TEMPS ARE 5 TO 10 DEGREES LOWER
THAN 5 HOURS AGO. WITH THE CLEAR SKIES AND WINDS
WEAKENING...TONIGHT LOOKS LIKE A NIGHT WHERE THE BOTTOM COULD DROP
OUT. THE NEXT COUPLE OF HOURS WILL TELL A LOT ABOUT HOW COLD WE
COULD GET TONIGHT. AS SUCH...LOWERED LOWS BY 3 TO 4 DEGREES TO
HEDGE TOWARDS LOWER TEMPS. IF THE DEWPOINTS DONT CHANGE MUCH WHEN
WE DECOUPLE THEN MAY NEED TO GO EVEN LOWER. WILL MONITOR AND
DECIDE WHAT TO DO AROUND 10PM. HAVE INCLUDED THE RECORD LOWS FOR
TONIGHT AS IT COULD BE POSSIBLE THAT WE COULD SEE TEMPS CLOSE TO
THEM TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 305 PM CDT WED APR 22 2015
THIS EVENING AND TONIGHT...SFC PRESSURE GRADIENT WILL WEAKEN
DRAMATICALLY AND ATMOSPHERE WILL DECOUPLE TO SOME EXTENT. THE SFC
HIGH PRESSURE AXIS WILL STAY WEST OF THE AREA ACROSS CENTRAL
IOWA...SO WINDS AROUND 5 KTS ARE FORECAST THROUGH THE NIGHT. CLEAR
SKIES AND VERY DRY AIR WILL SET THE STAGE FOR WELL BELOW NORMAL LOW
TEMPS IN THE MID 20S TO LOWER 30S.
WITH VEGETATION GREEN-UP WELL UNDERWAY AND LOCAL KNOWLEDGE FROM IOWA
STATE UNIVERSITY THAT FRUIT TREES ARE NOW SUSCEPTIBLE TO TEMPS IN
THE UPPER 20S...WILL ISSUE A FREEZE WARNING FOR THE ENTIRE AREA.
STARTED THE WARNING AT 2 AM CDT OVER NORTHERN TWO-THIRDS OF THE
FORECAST AREA WHERE MID TO UPPER 20S ARE FORECAST...AND AT 4 AM
OVER THE SOUTHERN THIRD WHERE UPPER 20S TO LOWER 30S ARE FORECAST.
BOTH WARNING SEGMENTS WILL EXPIRE AT 8 AM CDT THURSDAY MORNING.
THURSDAY...FINALLY MUCH LIGHTER WINDS...GENERALLY UNDER 15 MPH OUT
OF THE NW. OTHERWISE MOSTLY CLEAR SKIES WILL HELP TEMPS REACH TO
NEAR 60 F ON AVG.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT WED APR 22 2015
ANOTHER COLD NIGHT WILL BEGIN THE EXTENDED...AS SURFACE HIGH
PRESSURE REMAINS OVER THE AREA. WARM ADVECTION ALOFT WILL RESULT IN
CIRRUS AND POSSIBLE MID CLOUDS AFTER LATE EVENING...THUS...LOWS
SHOULD OCCUR AROUND MIDNIGHT...FOLLOWED BY STEADY OR RISING
TEMPERATURES. LOWS MAY DIP NEAR 32 IN THE EAST...BUT SHOULD HOLD IN
THE UPPER 30S TO AROUND 40 IN THE WEST 1/3.
LOOKING AT FRIDAY THROUGH THE WEEKEND...MODELS CONTINUE TO SHOW A
WINTER LIKE SYSTEM AFFECTING THE REGION...WITH A CLOSED MID LEVEL
LOW...OVER IOWA...AND SURFACE LOW IN MISSOURI. THIS SYSTEM SHOULD
PRODUCE WIDESPREAD STRATIFORM RAINS...MUCH LIKE A SNOW
EVENT...WOULD...ALONG WITH COLD TEMPERATURES AND EAST WINDS.
THUS...A DEFORMATION ZONE OF RAIN WILL LIKELY IMPACT OUR ENTIRE
CWA...BUT MOST CERTAINLY IN THE SOUTH 1/2. POPS ARE FORECAST
CATEGORICAL FRIDAY NIGHT...AND SATURDAY MORNING IN THE SOUTH TO
ACCOUNT FOR WIDESPREAD LIGHT TO MODERATE RAIN.
RAIN...EAST WINDS...AND CLOUDS WILL KEEP SATURDAY COOL...BUT ENOUGH
OF FRIDAY SHOULD SEE FILTERED SUN TO GET HIGHS BACK TO THE MID TO
UPPER 50S. SATURDAY WILL BE HELD TO THE UPPER 40S TO LOWER 50S...AND
THAT TOO COULD BE OPTIMISTIC IF THE RAINS MATERIALIZE AS PERSISTENT
AS THE GFS AND ECMWF BOTH SHOW.
FOLLOWING THIS WEEKEND RAIN SYSTEM...MODELS ARE QUICKLY SHOWING A
RETURN TO NORTHWEST FLOW ON THE WESTERN FLANK OF THE DOMINANT
EASTERN CONUS UPPER LOW. THIS COLDER THAN NORMAL PATTERN MAY STAY IN
PLACE THROUGH THE EARLY DAYS OF MAY. WHILE SOME RAIN SHOWERS WILL BE
POSSIBLE IN CLIPPER TYPE FORCING...THE MAIN IMPACTS WILL MOST
CERTAINLY BE MORE BREEZY...DEEPLY MIXED DAYS...WITH HIGHS GENERALLY
BELOW NORMAL.
ERVIN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1127 PM CDT WED APR 22 2015
VFR CONDITIONS WILL DOMINATE THE PERIOD WITH LIGHTER WINDS TODAY
ACROSS THE AREA. SOME VERY ISOLATED CUMULUS CLOUDS COULD
DEVELOP...BUT NOTHING IS EXPECTED TO AFFECT VSBYS OR CEILINGS AT
THE TAF SITES. ANOTHER SYSTEM TO OUR WEST WILL LEAD THE WINDS TO
SHIFT TO THE EAST LATE IN THE PERIOD. WINDS WILL BE LIGHT AFTER
SUNSET TODAY AND MOST LIKELY FROM THE EAST AT ALL SITES.
&&
.CLIMATE...
ISSUED AT 812 PM CDT WED APR 22 2015
RECORD LOWS FOR APR 23...
BURLINGTON ...24...1910
CEDAR RAPIDS...20...1927
DUBUQUE...22...1910
MOLINE...22...1910
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FREEZE WARNING UNTIL 8 AM CDT THURSDAY FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...FREEZE WARNING UNTIL 8 AM CDT THURSDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FREEZE WARNING UNTIL 8 AM CDT THURSDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...GIBBS
SYNOPSIS...UTTECH
SHORT TERM...UTTECH
LONG TERM...ERVIN
AVIATION...GIBBS
CLIMATE...GIBBS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
605 PM CDT FRI APR 24 2015
...UPDATE TO AVIATION...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1234 PM CDT FRI APR 24 2015
THE SHORT-FUSE SEVERE WEATHER COMPOSITE AT MIDDAY WAS SHOWING A
THREAT AREA STARTING TO DEVELOP ALONG THE SLOWLY NORTHWARD ADVANCING
WARM FRONT ACROSS WEST-CENTRAL KANSAS. SURFACE-BASED CAPE WAS
APPROACHING 1000 J/KG PER LAPS ANALYSIS AS OF 16Z. A SYNOPTIC DRY
INTRUSION/DRYLINE WILL CONTINUE TO ADVANCE NORTHEASTWARD, SHUNTING
THE SURFACE-BASED INGREDIENTS FOR SEVERE THUNDERSTORMS UP TOWARD THE
I-70 CORRIDOR. BY 21Z, THE HRRR INDICATES DEEP MOIST CONVECTION
DEVELOPING ALONG THE WARM FRONT BY 20-21Z. THERE SHOULD BE PRETTY
GOOD LOW LEVEL SHEAR ALONG THE FRONT WITH AMPLE STREAMWISE VORTICITY
TO INGEST INTO AN INCIPIENT SUPERCELL STORM. THE HRRR HAS SHOWN A
PERSISTENT LONG-TRACK UPDRAFT HELICITY SIGNAL, WHICH WOULD SUPPORT A
FAIRLY LONG-LIVED SUPERCELL THUNDERSTORM. IT CERTAINLY APPEARS THE
BEST TORNADO THREAT WILL BE UP ALONG THE FRONT ALONG THE I-70
CORRIDOR, WITH THE MOST VIGOROUS SURFACE-BASED STORMS EXITING OUR
AREA OF RESPONSIBILITY (EAST OF ELLIS AND RUSH COUNTY) BY AS SOON AS
23Z. WE WILL HAVE TO WATCH THE BENT-BACK REGION OF ENHANCED
CAPE/MOISTURE WESTWARD ALONG I-70 FOR FUTURE GROWTH OF DEEP MOIST
CONVECTION AS SOME OF THE LATEST RUNS OF THE HRRR SUGGEST. THERE
WILL LIKELY BE A LOCALIZED HEAVY RAIN RISK ALONG THE FRONT UP THERE
SHOULD THE HRRR PAN OUT. THE SHORTWAVE TROUGH WILL QUICKLY EXIT THE
SOUTHWEST KANSAS REGION BY LATE EVENING WITH SOME WESTERLY LOW LEVEL
MOMENTUM FINALLY PUSHING INTO OUR REGION ESPECIALLY AFTER 06Z
TONIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 111 PM CDT FRI APR 24 2015
BY THE BEGINNING OF THE EXTENDED PERIOD, AN UPPER TROUGH WILL BE BE
DEEPENING OVER THE WESTERN STATES THANKS TO A 120+ KNOT JET LOCATED
ON THE WEST SIDE OF THE TROUGH. THIS TROUGH WILL CONTINUE TO DEEPEN
AND CLOSE OFF INTO AN UPPER LOW OVER NEW MEXICO ON SUNDAY BEFORE
MOVING OUT ACROSS THE SOUTHERN PLAINS EARLY NEXT WEEK. AS THE TROUGH
AND LOW DEVELOP, LOW PRESSURE OVER EASTERN COLORADO WILL DROP SOUTH
INTO THE TEXAS PANHANDLE WHILE A COOL FRONT DROPS SOUTH ACROSS
WESTERN KANSAS SATURDAY NIGHT. COOL AND MOIST LOW LEVEL EASTERLY
FLOW WILL DEVELOP OVER SOUTHWEST KANSAS BEHIND THE FRONT. THIS WILL
LEAD TO CLOUDY AND COOLER CONDITIONS ALONG WITH INCREASING CHANCES
FOR SHOWERS AND POSSIBLY A FEW THUNDERSTORMS LATE SUNDAY THROUGH THE
EARLY PART OF NEXT WEEK.
THE MEDIUM RANGE MODELS HAVE BEEN HOLDING ON TO THEIR RESPECTIVE
SOLUTIONS REGARDING THE TRACK OF THE UPPER LOW AS IT MOVES OUT
THROUGH THE SOUTHERN PLAINS MONDAY AND TUESDAY. THE TRACK OF THE LOW
WILL HAVE AN IMPACT ON PRECIPITATION CHANCES AND RAINFALL AMOUNTS
ACROSS SOUTHWEST KANSAS. THE GFS CONTINUES TO BE FARTHEST NORTH WITH
ITS TRACK ACROSS THE TEXAS PANHANDLE THROUGH OKLAHOMA INTO MISSOURI.
THIS MODEL IS SHOWING DECENT RAINFALL ACROSS MUCH OF CENTRAL AND
SOUTHWEST KANSAS. BOTH THE ECMWF AND CANADIAN MODELS TRACK THE UPPER
LOW OUT ACROSS WESTERN AND NORTHERN TEXAS INTO ARKANSAS AND HAVE THE
BEST RAINFALL AMOUNTS CONFINED TO AREAS ALONG AND JUST NORTH OF THE
OKLAHOMA BORDER. THE CURRENT FORECAST THROUGH MONDAY LOOKS
REASONABLE WITH LIKELY POPS NEAR THE OKLAHOMA BORDER THAT DIMINISH
FARTHER NORTH AND HAVE ONLY MADE SOME MINOR ADJUSTMENTS.
GIVEN THE CLOUDY, COOL AND MOIST CONDITIONS THAT DEVELOP, HIGH
TEMPERATURES ON SUNDAY AND MONDAY WILL LIKELY NOT GET OUT OF THE 50S
IN MANY LOCATIONS ESPECIALLY ON MONDAY.
THE REMAINDER OF THE EXTENDED PERIOD SHOULD SEE DRIER AND WARMER
WEATHER RETURNING AS UPPER LEVEL RIDGING BUILDS BACK OVER THE
CENTRAL PLAINS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 602 PM CDT FRI APR 24 2015
SCATTERED THUNDERSTORMS WILL CONTINUE TO MOVE NORTHEAST ACROSS
SOUTHWEST AND CENTRAL KANSAS THROUGH LATE THIS EVENING INCREASING
THE POTENTIAL FOR BRIEF PERIODS OF MVFR CIGS/VSBYS IN THE VICINITY
OF ALL TAF SITES. OTHERWISE, VFR CONDITIONS WILL PREVAIL AT ALL
TAF SITES THROUGH EARLY SATURDAY AFTERNOON. VARIABLE WINDS OF 15
TO 25KT ARE LIKELY EARLY THIS EVENING AS SHOWERS AND ISOLATED
THUNDERSTORMS MOVE NORTHEAST ACROSS WESTERN KANSAS. WINDS WILL
THEN TURN WESTERLY 10 TO 20KT EARLY SATURDAY MORNING AS A SURFACE
TROUGH SHIFTS EASTWARD ACROSS WESTERN KANSAS. NORTHERLY WINDS ARE
EXPECTED TO DEVELOP MID TO LATE MORNING SATURDAY AS A COLD FRONT
PUSHES SOUTHWARD ACROSS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 50 79 48 61 / 80 10 10 30
GCK 48 78 48 57 / 90 10 20 40
EHA 48 79 47 66 / 40 10 10 50
LBL 49 81 48 67 / 60 10 10 40
HYS 51 73 46 57 / 80 10 10 20
P28 53 81 52 65 / 40 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...GERARD
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
310 PM MDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 112 PM MDT THU APR 23 2015
LOW CLOUDS THAT WERE PRESENT ACROSS THE AREA DURING THE MORNING
HOURS CONTINUED TO LINGER FOR SOME LOCATIONS ACROSS THE TRI STATE
AREA IN THE EARLY AFTERNOON ON VISIBLE SATELLITE IMAGERY...HOWEVER
MOST LOCATIONS WERE UNDER PARTLY TO MOSTLY CLEAR SKIES. RAP 500 MB
ANALYSIS AND WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH ACROSS
THE CENTRAL HIGH PLAINS REGION...HOWEVER A LONGWAVE TROUGH ACROSS
THE GREAT BASIN REGION WAS MOVING EASTWARD INTO THE CENTRAL HIGH
PLAINS.
THE ADVANCING TROUGH WILL BRING SOME POCKETS OF HIGHER POTENTIAL
VORTICITY VALUES ACROSS THE TRI STATE AREA LATER THIS AFTERNOON AND
TONIGHT...WHICH WILL HELP DESTABILIZE THE ATMOSPHERE AND CAUSE
STORMS TO DEVELOP. A SURFACE STATIONARY BOUNDARY TO THE WEST ALONG
THE COLORADO FRONT RANGE WILL ALSO PROVIDE THE NEEDED PUSH AT THE
SURFACE TO GET STORMS GOING. MOST MODEL GUIDANCE HAS INITIATION
OCCURRING SOMETIME BETWEEN 21 AND 00Z IN EASTERN COLORADO WITH
STORMS GETTING GOING BY 00Z. PROFILE CAPE BETWEEN 1000 AND 1500
J/KG AND BULK SHEAR BETWEEN 30 AND 35 KTS MAY BE ENOUGH TO CAUSE
SOME STORMS TO PRODUCE LARGE HAIL...AND DRY MID LEVELS IN MODEL
SOUNDINGS WITH DCAPE BETWEEN 800 AND 1000 J/KG COULD RESULT IN
DAMAGING WINDS GUSTS. THE SHEAR VALUES DIMINISH OVERNIGHT...BUT
CAPE WILL STILL BE PRESENT OVERNIGHT AS STORMS MOVE EASTWARD.
THEREFORE...EXPECTING STORMS TO CONTINUE OVERNIGHT FOR SOME
LOCATIONS.
THE SURFACE STATIONARY FRONTAL BOUNDARY WILL REMAIN DRAPED ACROSS
THE TRI STATE AREA OVERNIGHT...WHICH WILL BRING SOUTHEAST WINDS AT
THE SURFACE AND INCREASED RELATIVE HUMIDITIES OVERNIGHT. AS A
RESULT...FOG WILL DEVELOP AND CLOUD COVER WILL REMAIN INCREASED
OVERNIGHT. EXPECTING LOW TEMPERATURES TO BE SLIGHTLY WARMER AS A
RESULT OF THE BLANKETING CLOUD COVER IN THE UPPER 40S.
FOG AND LOWER CLOUDS WILL BEGIN TO DIMINISH TOWARD THE EARLY TO MID
MORNING HOURS...BUT CLOUDS WILL RETURN DURING THE EARLY AFTERNOON AS
A SURFACE WARM FRONT APPROACHES THE TRI STATE AREA. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN THE LATE MORNING TO EARLY
AFTERNOON HOURS...MAINLY EAST OF HIGHWAY 83. CAPE VALUES AROUND
1000 J/KG AND BULK SHEAR BETWEEN 35 AND 40 KTS WILL BRING SOME
SEVERE POTENTIAL WITH LARGE HAIL AND DAMAGING WINDS...ALTHOUGH THE
MAIN ATMOSPHERIC DYNAMICS ARE WELL EAST OF OUR FORECAST AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM MDT THU APR 23 2015
THE UPPER TROUGH AND SURFACE LOW MOVING ACROSS THE AREA ON FRIDAY
WILL CONTINUE TO LIFT ENE AS A CLOSED LOW FRIDAY NIGHT WITH WEAK
SHORT WAVE RIDGING ALOFT OVER THE CENTRAL HIGH PLAINS ON SATURDAY.
SATURDAY LOOKS MOSTLY DRY BETWEEN SYSTEMS WITH THE NEXT LOW
PRESSURE CENTER DIVING INTO THE SOUTHWEST U.S. SOUTH OF THE
4-CORNERS REGION DURING BY SUNDAY MORNING. THE LOW ALOFT MOVES
INTO THE WEST TEXAS PANHANDLE REGION BY MONDAY MORNING...MOVING
SLOWLY INTO POSITION OVER EAST TEXAS AND EAST OKLAHOMA BY TUESDAY
MORNING AS THE SURFACE LOW TRACKS FURTHER SOUTH ALONG THE GULF
COAST OF TEXAS.
WITH THE MAIN LOW PRESSURE AREA ACROSS THE SOUTH CENTRAL U.S. WELL
SOUTH OF THE FORECAST AREA...THE SATURDAY NIGHT THROUGH MONDAY
NIGHT TIME FRAME WILL REMAIN UNSETTLED ACROSS THE FORECAST AREA WITH
A CHANCE OF RAIN SHOWERS AND THUNDERSTORMS...BUT EXPECT THE BULK
OF THE PRECIPITATION TO STAY OVER THE SOUTHERN PLAINS. TUESDAY
THROUGH THURSDAY SHOULD BE DRY AS THE AMPLIFYING RIDGE OVER THE
WEST COAST MOVES OVER THE ROCKIES AND HIGH PLAINS REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1147 AM MDT THU APR 23 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE IN THE VICINITY OF
KGLD THIS AFTERNOON AND TONIGHT...WHICH WILL BRING GUSTY WINDS.
ONCE STORMS PASS THE VICINITY OF KGLD...LOWER FLIGHT CATEGORIES
WILL BE PRESENT DUE TO CEILING HEIGHTS AND VISIBILITY REDUCTIONS.
THUNDERSTORMS WILL DEVELOP IN THE VICINITY OF KMCK THIS
AFTERNOON...AND RAIN SHOWERS WILL DEVELOP IN THE EVENING AND
OVERNIGHT HOURS. LOWER FLIGHT CATEGORIES WILL RESULT TONIGHT DUE
TO LOW CEILINGS AND REDUCED VISIBILITIES.
BOTH TERMINALS SHOULD SEE FLIGHT CONDITIONS IMPROVE IN THE MID
MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...LOCKHART
AVIATION...MK
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
343 PM CDT THU APR 23 2015
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CDT THU APR 23 2015
FORECAST ISSUES IN THE SHORT TERM CENTER AROUND THUNDERSTORM CHANCES
TONIGHT AND FRIDAY AND THE SEVERE WEATHER POTENTIAL ASSOCIATED WITH
THE STORMS.
THE ATMOSPHERE OVER THE HIGH PLAINS OF EASTERN COLORADO AND FAR WESTERN
KANSAS WAS BECOMING MODERATELY UNSTABLE WITH DAYTIME HEATING THIS
AFTERNOON. A SURFACE TROUGH OF LOW PRESSURE STRENGTHENING OVER EASTERN
COLORADO WAS ALSO PROVIDING SOME LOW LEVEL CONVERGENCE AND TRIGGERING
WIDELY SCATTERED THUNDERSTORMS. SPC MESOANALYSIS SHOWS 30- 40 KNOTS
OF SHEAR IN THE 0-6 KM LAYER BUT ABOVE THIS LAYER, STRONGER SHEAR
WAS IN PLACE IN THE PRESENCE OF A STRONG SUBTROPICAL JET. THE STORMS
OVER EASTERN COLORADO WILL BE IN A FAVORABLE ENVIRONMENT TO BECOME
ROTATING SUPERCELLS. GIVEN THE STRONG EVACUATION ALOFT, LARGE HAIL
WILL BE A GOOD POSSIBILITY. THE HRRR MODEL HAS BEEN VERY CONSISTENT
WITH THUNDERSTORMS MOVING INTO WESTERN KANSAS AROUND JOHNSON AND
SYRACUSE AND POINTS NORTH THIS EVENING AROUND 23Z-01Z AND HAVE
KEPT THE BEST CHANCES IN THAT AREA EARLY THIS EVENING. AS THE
NIGHT CONTINUES, AN AREA OF THUNDERSTORMS COULD CONTINUE TO DEVELOP
OVER WEST CENTRAL AND NORTHWEST KANSAS AS A WEAK MID LEVEL DISTURBANCE
ALONG WITH THE LEFT EXIT REGION OF AN UPPER LEVEL SPEED MAX MOVES
OVER THE AREA. THE MODELS ALSO SHOW INCREASING SOUTHERLY FLOW AT THE
850 MILLIBAR LEVEL WHICH COULD ALSO HELP SUSTAIN THUNDERSTORMS THROUGH
THE NIGHT. THE BEST CHANCE FOR STORMS SHOULD BE ALONG AND/OR NORTH
OF HIGHWAY 50 AND 156. THE THREAT FOR SEVERE WEATHER SHOULD DIMINISH
SOMEWHAT AFTER DARK BUT CAN`T RULE OUT THE POSSIBILITY OF A FEW
ELEVATED HAILERS. CHANCES FOR STORMS WILL DIMINISH LATER TONIGHT
AS THE MID/UPPER LEVEL SUPPORT MOVES EAST OF THE AREA.
ON FRIDAY, THE MAIN UPPER TROUGH MOVES OUT INTO THE CENTRAL AND
SOUTHERN PLAINS. THE MODELS DEVELOP A SURFACE LOW OVER WEST CENTRAL
KANSAS WITH A FRONTAL BOUNDARY EXTENDING EAST FROM THE LOW. BY FRIDAY
AFTERNOON THE LOW WILL BE PROGRESSING EAST WHILE A DRYLINE PUSHES
EAST ACROSS SOUTHWEST THROUGH SOUTH CENTRAL KANSAS. THE UPPER LEVEL
JET PROPAGATES EAST THROUGH THE DAY. THE 18Z MODELS ARE NOW LOOKING
LESS FAVORABLE FOR SEVERE POTENTIAL AS THE BETTER 0-6 KM SHEAR WILL
BE TO THE SOUTH AND EAST OF THE DODGE CITY CWFA DURING THE MID/LATE
AFTERNOON HOURS. WITH SOME GOOD INSTABILITY OVER THE NORTHERN AND
EASTERN SECTIONS OF THE CWA, THERE WILL STILL BE POTENTIAL FOR
SOME SEVERE STORMS AS WELL AS THE POTENTIAL FOR TORNADOES ALONG
AND NORTH OF THE FRONTAL BOUNDARY OVER CENTRAL KANSAS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT THU APR 23 2015
THE WEAK UPPER LEVEL LOW WILL CONTINUE TO MOVE EASTWARD ACROSS
THE KS/NE BORDER FRIDAY NIGHT. THIS WILL HELP PUSH A SURFACE LOW
AND ASSOCIATED COLD FRONT THROUGH THE REMAINDER OF THE CWA AND
INTO EASTERN KANSAS. A FEW LINGERING THUNDERSTORMS WILL BE
POSSIBLE ACROSS CENTRAL KANSAS AS WELL AS AROUND THE I-70 CORRIDOR
IN THE EVENING WITH PRECIPITATION CHANCES COMING TO AN END
SOMETIME AFTER MIDNIGHT. NORTHWESTERLY WINDS WILL BE FELT BEHIND
THIS SYSTEM AND CONTINUE THROUGH THE MOST OF SATURDAY. SKIES LOOK
TO BECOME MOSTLY CLEAR BY SUNRISE SATURDAY AND CONTINUE THROUGH
THE DAY SATURDAY AS DRIER AIR MOVES INTO THE AREA. WINDS THEN
SHIFT TO MORE OF AN EASTERLY DIRECTION SATURDAY EVENING THROUGH
SUNDAY AS AN AREA OF LOW PRESSURE DEVELOPS AND INTENSIFIES
SOUTHWEST OF THE AREA. THIS OCCURS IN RESPONSE TO AN UPPER LEVEL
OPEN WAVE DIGGING INTO THE DESERT SOUTHWEST SATURDAY, INTENSIFYING
INTO AN UPPER LEVEL LOW OVER THE FOUR CORNER`S REGION SUNDAY.
MODELS THEN SUGGEST THAT THIS LOW WILL MOVE EASTWARD ACROSS THE
SOUTHERN PLAINS MONDAY INTO TUESDAY. HOWEVER, WITH THIS SYSTEM
BEING MORE THAN 4 DAYS OUT TIMING AND POSITION WILL MOST LIKELY
CHANGE OVER THE NEXT COUPLE OF MODEL RUNS. IF FUTURE MODEL RUNS
PREDICT THIS FEATURE TO MOVE FARTHER NORTH, THE CWA COULD SEE SOME
BENEFICIAL RAIN SUNDAY NIGHT THROUGH TUESDAY. NEVERTHELESS, HIGH
CLOUDS LOOK INCREASE IN COVERAGE SUNDAY AS THIS FEATURE MOVES
CLOSER TO THE AREA WITH MOSTLY CLOUDY SKIES EXPECTED SUNDAY NIGHT
THROUGH AT LEAST MONDAY. WINDS SHIFT TO MORE OF A NORTHERLY
DIRECTION BEHIND THIS SYSTEM THROUGH TUESDAY. UPPER LEVEL RIDGING
IS THEN EXPECTED TO BUILD INTO THE WESTERN UNITED STATES BEHIND
THIS SYSTEM WITH HIGH PRESSURE BEING THE DOMINATING FACTOR AT THE
SURFACE. THIS WILL BRING DRIER CONDITIONS TO WESTERN KANSAS FOR
THE REMAINDER OF THE WEEK.
AS FOR TEMPERATURES, LOWS FRIDAY NIGHT THROUGH MONDAY NIGHT WILL
GENERALLY BE IN THE 40S WITH THE EXCEPTION OF SOUTH CENTRAL KANSAS
FRIDAY NIGHT WHERE LOWER 50S WILL BE POSSIBLE AND WEST CENTRAL
KANSAS MONDAY NIGHT WHERE UPPER 30S COULD BE POSSIBLE. HIGHS LOOK
TO BE IN THE 70S WITH A FEW AREAS ACROSS THE KS/OK BORDER REACHING
INTO THE LOWER 80S SATURDAY THEN DECREASE INTO THE 60S SUNDAY. THE
COLDEST DAY OVER THE EXTENDED PERIOD LOOKS TO BE ON MONDAY WITH
HIGHS POSSIBLY ONLY REACHING TO AROUND 60 DEGREES. HIGHS ARE
FORECASTED TO REACH INTO THE MID 60S TUESDAY WITH 70S POSSIBLE
WEDNESDAY. LOWS TUESDAY THROUGH THURSDAY MORNING LOOK TO DIP INTO
THE 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1235 PM CDT THU APR 23 2015
MVFR CIGS SHOULD CONTINUE THROUGH THE AFTERNOON AT THE GARDEN
CITY AND DODGE CITY TERMINALS. VFR CONDITIONS SHOULD PREVAIL AT
HAYS ALTHOUGH SOME MVFR CIGS COULD DEVELOP OFF AND ON THIS
AFTERNOON. WIDELY SCATTERED THUNDERSTORMS DEVELOPING OVER EASTERN
COLORADO LATER THIS AFTERNOON ARE EXPECTED TO MOVE INTO WESTERN
KANSAS EARLY THIS EVENING. THERE IS SOME UNCERTAINTY WHETHER THE STORMS
WILL IMPACT OPERATIONS AT GARDEN CITY AND DODGE CITY AND HAVE
INCLUDED VCTS AT THOSE TERMINALS. HAYS WILL HAVE A BETTER CHANCE
TO BE IMPACTED AND WILL CARRY A TEMPO GROUP THERE LATER TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 54 81 49 78 / 40 20 20 10
GCK 50 77 48 77 / 50 20 20 10
EHA 49 76 47 79 / 30 10 10 10
LBL 54 80 48 81 / 30 10 10 10
HYS 51 73 50 73 / 60 40 40 10
P28 56 82 52 80 / 30 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GERARD
LONG TERM...HOVORKA_42
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS GOODLAND KS
112 PM MDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 112 PM MDT THU APR 23 2015
LOW CLOUDS THAT WERE PRESENT ACROSS THE AREA DURING THE MORNING
HOURS CONTINUED TO LINGER FOR SOME LOCATIONS ACROSS THE TRI STATE
AREA IN THE EARLY AFTERNOON ON VISIBLE SATELLITE IMAGERY...HOWEVER
MOST LOCATIONS WERE UNDER PARTLY TO MOSTLY CLEAR SKIES. RAP 500 MB
ANALYSIS AND WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH ACROSS
THE CENTRAL HIGH PLAINS REGION...HOWEVER A LONGWAVE TROUGH ACROSS
THE GREAT BASIN REGION WAS MOVING EASTWARD INTO THE CENTRAL HIGH
PLAINS.
THE ADVANCING TROUGH WILL BRING SOME POCKETS OF HIGHER POTENTIAL
VORTICITY VALUES ACROSS THE TRI STATE AREA LATER THIS AFTERNOON AND
TONIGHT...WHICH WILL HELP DESTABILIZE THE ATMOSPHERE AND CAUSE
STORMS TO DEVELOP. A SURFACE STATIONARY BOUNDARY TO THE WEST ALONG
THE COLORADO FRONT RANGE WILL ALSO PROVIDE THE NEEDED PUSH AT THE
SURFACE TO GET STORMS GOING. MOST MODEL GUIDANCE HAS INITIATION
OCCURRING SOMETIME BETWEEN 21 AND 00Z IN EASTERN COLORADO WITH
STORMS GETTING GOING BY 00Z. PROFILE CAPE BETWEEN 1000 AND 1500
J/KG AND BULK SHEAR BETWEEN 30 AND 35 KTS MAY BE ENOUGH TO CAUSE
SOME STORMS TO PRODUCE LARGE HAIL...AND DRY MID LEVELS IN MODEL
SOUNDINGS WITH DCAPE BETWEEN 800 AND 1000 J/KG COULD RESULT IN
DAMAGING WINDS GUSTS. THE SHEAR VALUES DIMINISH OVERNIGHT...BUT
CAPE WILL STILL BE PRESENT OVERNIGHT AS STORMS MOVE EASTWARD.
THEREFORE...EXPECTING STORMS TO CONTINUE OVERNIGHT FOR SOME
LOCATIONS.
THE SURFACE STATIONARY FRONTAL BOUNDARY WILL REMAIN DRAPED ACROSS
THE TRI STATE AREA OVERNIGHT...WHICH WILL BRING SOUTHEAST WINDS AT
THE SURFACE AND INCREASED RELATIVE HUMIDITIES OVERNIGHT. AS A
RESULT...FOG WILL DEVELOP AND CLOUD COVER WILL REMAIN INCREASED
OVERNIGHT. EXPECTING LOW TEMPERATURES TO BE SLIGHTLY WARMER AS A
RESULT OF THE BLANKETING CLOUD COVER IN THE UPPER 40S.
FOG AND LOWER CLOUDS WILL BEGIN TO DIMINISH TOWARD THE EARLY TO MID
MORNING HOURS...BUT CLOUDS WILL RETURN DURING THE EARLY AFTERNOON AS
A SURFACE WARM FRONT APPROACHES THE TRI STATE AREA. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN THE LATE MORNING TO EARLY
AFTERNOON HOURS...MAINLY EAST OF HIGHWAY 83. CAPE VALUES AROUND
1000 J/KG AND BULK SHEAR BETWEEN 35 AND 40 KTS WILL BRING SOME
SEVERE POTENTIAL WITH LARGE HAIL AND DAMAGING WINDS...ALTHOUGH THE
MAIN ATMOSPHERIC DYNAMICS ARE WELL EAST OF OUR FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 303 AM MDT THU APR 23 2015
ANOTHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA EARLY SUNDAY. THIS
WILL BRING THE POSSIBILITY OF PRECIPITATION TO THE FORECAST AREA
THROUGH MONDAY NIGHT/TUESDAY. THE UPPER LEVEL LOW WILL TRACK TO THE
SOUTH TOWARDS TEXAS AND OKLAHOMA ON SUNDAY AND MONDAY. HIGH PRESSURE
WILL BUILD INTO THE HIGH PLAINS ON WEDNESDAY BRINGING DRIER AND
WARMER CONDITIONS.
MODELS ARE IN DISAGREEMENT ON HOW TO HANDLE THE TROUGH AS IT MOVES
INTO THE CONUS FROM CANADA MONDAY NIGHT. GFS SHOWS A LOW DEVELOPING
OVER CANADA AND MOVING SOUTH TOWARDS THE SOUTHERN LOW. THIS AFFECTS
THE TIMING OF THE RIDGE BUILDING INTO THE AREA BEHIND THE SYSTEM.
WILL HAVE TO SEE HOW FUTURE MODEL RUNS HANDLE THIS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1147 AM MDT THU APR 23 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE IN THE VICINITY OF
KGLD THIS AFTERNOON AND TONIGHT...WHICH WILL BRING GUSTY WINDS.
ONCE STORMS PASS THE VICINITY OF KGLD...LOWER FLIGHT CATEGORIES
WILL BE PRESENT DUE TO CEILING HEIGHTS AND VISIBILITY REDUCTIONS.
THUNDERSTORMS WILL DEVELOP IN THE VICINITY OF KMCK THIS
AFTERNOON...AND RAIN SHOWERS WILL DEVELOP IN THE EVENING AND
OVERNIGHT HOURS. LOWER FLIGHT CATEGORIES WILL RESULT TONIGHT DUE
TO LOW CEILINGS AND REDUCED VISIBILITIES.
BOTH TERMINALS SHOULD SEE FLIGHT CONDITIONS IMPROVE IN THE MID
MORNING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...JBH
AVIATION...MK
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
613 AM CDT THU APR 23 2015
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 416 AM CDT THU APR 23 2015
SPLIT UPPER SYNOPTIC FLOW LEFT WESTERN KANSAS UNDER A WEAK FLOW
ALOFT AS SURFACE HIGH PRESSURE CONTINUED TO SLIDE EAST INTO THE
MISSISSIPPI VALLEY. TO THE SOUTH, SCATTERED CONVECTION WAS DECAYING
ALONG A STATIONARY FRONT NEAR THE RED RIVER VALLEY AS EASTERLY
SURFACE FLOW AND BOUNDARY LAYER COOLING CONTRIBUTED TO THE EXPANSION
OF STRATUS ACROSS THE PANHANDLES AND CENTRAL AND WESTERN KANSAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CDT THU APR 23 2015
THE NAM CONTINUE TO EXPAND THE STRATUS ACROSS THE ENTIRE AREA THIS
MORNING LEADING TO CLOUD BASES BETWEEN 2 AND 3 KFT DURING THE DAY.
INTENSE LATE APRIL INSOLATION SHOULD AID BOUNDARY LAYER MIXING,
EFFECTIVELY ERODING THE EXTREME WESTERN EDGE ALTHOUGH THE EXTENT TO
HOW FAR EAST THE STRATUS SCATTERS IS UNCERTAIN. DRY MID LEVELS MAY
CONTRIBUTE TO A DRIZZLE SETUP BETWWEEN ROUGHLY HIGHWAYS 83 AND 283
LATE THIS MORNING AND SPREADING EAST IN THE AFTERNOON. HIGHER
TERRAIN SURFACE BASED CONVECTION IS EXPLICITLY DEVELOPED BY THE 4 KM
NAM ACROSS SOUTHEAST COLORADO LATE IN THE DAY, AND DRIVEN EAST IN
THE HIGH (30-40 KNOT) SHEAR ENVIRONMENT BY THE EVENING, BUT TO A
MUCH MORE STABLE BOUNDARY LAYER IN KS. AT THE SAME TIME, THE
EVOLUTION OF THE UPPER PATTERN SUGGESTS A 700 MB TROUGH MOVING INTO
THE REGION, SETTING UP AN ISENTROPIC LIFT ZONE FOR THE OVERNIGHT,
WHICH MAY BE FAIRLY LIMITED GIVEN THE DRY MID LEVELS.
MOS/BLENDS FORECASTS UPPER 50S WITH MODELS SHOWING CLOSER TO 70 IN
THE AREA OF MORE ABUNDANT SUN TODAY. UNCERTAINTY WILL THEN INCREASE
INTO TONIGHT AS THE EFFECTS OF ANY POTENTAIL CONVECTION COULD
IMPACT TEMPERATURES, AREAL EXTENT OF PRECIPITATION AND LEFTOVER RAIN
COOLED STRATUS OR FOG.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 334 AM CDT THU APR 23 2015
MAIN UNCERTAINTY ON FRIDAY WILL BE HOW FAR NORTH THE WARM FRONT
WILL BE BY LATE DAY AND WHERE THE MOISTURE RETURN AND LOW LEVEL
FORCING BE LOCATED FRIDAY EVENING. AT THIS TIME THE NAM AND NMM
SUGGESTS THAT BETTER MOISTURE RETURN WILL TO BE LOCATED EAST OF
HIGHWAY 283 WHILE THE GFS, AND ARW WERE MORE PROGRESSIVE AND MOVED
THE FRONT, DRYLINE, MOISTURE, AND BETTER INSTABILITY FURTHER EAST
INTO CENTRAL KANSAS. GIVEN THE UNCERTAINTY BETWEEN THE MODELS
EARLY THIS MORNING WILL STAY CLOSE TO THE PREVIOUS FORECAST FOR
PRECIPITATION CHANCES WHICH SEEMS TO BE A NICE BLEND BETWEEN THE
TWO EXTREMES LATE FRIDAY INTO FRIDAY NIGHT. ACROSS EXTREME
SOUTHWEST KANSAS FRIDAY AFTERNOON A WEST WIND WILL DEVELOP BY THE
EARLY AFTERNOON AND DEW POINTS ARE EXPECTED TO FALL BACK INTO THE
30S. THIS WILL RESULT IN INCREASE FIRE DANGER LEVELS, HOWEVER
GIVEN THE RECENT GREEN UP BASED ON THE FUEL STATUS PAGE CONDITIONS
DO NOT LOOK FAVORABLE FOR A FIRE WATCH AT THIS TIME.
AS AN UPPER LEVEL TROUGH CROSSES THE CENTRAL PLAINS FRIDAY NIGHT
AND A COLD FRONT WILL DROP SOUTH ACROSS NEBRASKA. THIS FRONT WILL
CONTINUE TO MOVE SOUTH ACROSS WESTERN KANSAS ON SATURDAY WHICH
WILL ALLOW SOME COOLER AIR TO MOVE INTO NORTHERN KANSAS BY LATE
DAY. AT THIS TIME BASED ON THE TIMING OF THIS FRONTAL PASSAGE
SATURDAY AFTERNOON ANOTHER UNSEASONABLY WARM DAY CAN BE EXPECTED
ACROSS MUCH OF SOUTHWEST KANSAS. ACROSS NORTH CENTRAL KANSAS
TEMPERATURES ARE EXPECTED TO BE ROUGHLY 8-10 DEGREE COOLER. HIGHS
ON SATURDAY WILL VARY FROM THE LOWER 70S ALONG I-70 CORRIDOR TO
THE LOWER 80S NEAR THE OKLAHOMA BORDER.
THE COLD FRONT WILL BECOME NEARLY STATIONARY SATURDAY NIGHT AND
EXTEND FROM SOUTHEAST COLORADO INTO WESTERN OKLAHOMA. WARM AIR
ADVECTION AND ISENTROPIC LIFT DEVELOPS NORTH OF THIS FRONT LATE
SATURDAY NIGHT/EARLY SUNDAY AS ANOTHER UPPER LEVEL SYSTEM DEEPENS
AS IT CROSSES THE FOUR CORNERS REGION. CLOUDS WILL INITIALLY BE ON
THE INCREASE FOLLOWED BY IMPROVING CHANCES OF PRECIPITATION LATE
THIS WEEKEND GIVEN EAST/SOUTHEASTERLY UP SLOPE FLOW, MOISTURE
NORTH OF THE STATIONARY FRONT AND IMPROVING ISENTROPIC LIFT AHEAD
OF THIS DEVELOPING UPPER LEVEL LOW.
CLOUDY SKIES, COOL TEMPERATURES AND HIGH CHANCES FOR
PRECIPITATION CAN THEN BE EXPECTED FROM THROUGH EARLY NEXT WEEK AS
THE UPPER LOW SLOWLY MOVES FROM NEW MEXICO, ACROSS TEXAS PANHANDLE
INTO OKLAHOMA EARLY NEXT WEEK. GIVEN THE LATEST TRACK OF THIS
UPPER LEVEL SYSTEM THE AREA MORE FAVORABLE FOR WIDESPREAD
PRECIPITATION WILL BE SOUTH OF HIGHWAY 156.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 611 AM CDT THU APR 23 2015
06Z NAM BUFR SOUNDINGS WERE SIMILAR TO THE 00Z MODEL RUNS WITH
MOISTURE AND WEAK LIFT INCREASING IN THE 900MB TO 750MB LEVEL
TODAY. BASED ON THE 06Z NAM BUFR SOUNDING ALONG WITH THE LATEST
HRRR AND RAP MVFR CEILINGS ARE EXPECTED TO LOWER INTO IFR CATEGORY
AT DDC AND GCK BETWEEN 15Z AND 18Z AS PATCHY DRIZZLE DEVELOPS. AT
HYS CEILINGS ARE EXPECTED TO FALL BACK INTO THE IFR CATEGORY
BETWEEN 21Z THURSDAY AND 00Z FRIDAY. AFTER 00Z FRIDAY THE CHANCE
FOR FOG WILL INCREASE AND STATUS WILL CONTINUE TO LOWER AS THE
SURFACE TO 900MB LEVEL SATURATES AND A SOUTHEAST WINDS CONTINUE AT
10 KNOTS OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 55 79 50 / 20 40 20 20
GCK 63 51 77 47 / 20 60 20 20
EHA 72 49 79 47 / 20 40 10 10
LBL 66 54 81 49 / 20 30 10 10
HYS 60 51 73 49 / 10 60 40 50
P28 61 54 81 52 / 10 50 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1127 PM MDT WED APR 22 2015
.UPDATE...
ISSUED AT 952 PM MDT WED APR 22 2015
MODELS COMING INTO FAIRLY GOOD AGREEMENT WITH THE LIKELIHOOD OF
FOG DEVELOPING OVER KIT CARSON/CHEYENNE COUNTIES LATE TONIGHT AND
EARLY THURSDAY MORNING. CURRENTLY THINKING VISIBILITIES OF A MILE
OR SO ARE LIKELY...WITH SOME LOCATIONS POSSIBLY DROPPING CLOSE TO
A QUARTER MILE.
TOOK OUT THE RAINFALL CHANCES FOR THE EVENING SINCE THE STORMS
JUST WEST OF THE AREA HAVE DIED. STILL THINKING SOME DRIZZLE/LIGHT
RAINFALL IS POSSIBLE LATE TONIGHT AND EARLY TOMORROW MORNING WITH
THE FOG.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED APR 22 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
NORTHERN AND SOUTHERN JET STREAMS SPLIT AROUND OUR CWA...WITH WEAK
RIDGING EXTENDING FROM THE SOUTHERN PLAINS AND ACROSS THE CENTRAL
ROCKIES. PACIFIC MOISTURE PLUME IS UNDERCUTTING UPPER RIDGE WITH
WEAK SHORTWAVE TROUGHS ROTATING NORTH AND EAST THROUGH THE
SOUTHERLY STORM TRACK. AT THE SURFACE A STATIONARY FRONT HAS
SLOWLY BEGUN THE PROCESS OF MOVING EAST WITH RADAR SHOWING
CONVECTION DEVELOPING IN THE WEAKLY UNSTABLE AIR MASS BEHIND THIS
FEATURE OVER THE HIGHER TERRAIN IN COLORADO.
THIS AFTERNOON TONIGHT...INITIAL CONCERN IS ON COVERAGE AND
PROGRESS OF THUNDERSTORM ACTIVITY IN COLORADO TOWARDS OUR CWA.
GUIDANCE SHOWS INCREASING INSTABILITY IN OUR WESTERN CWA...WHICH
COULD FAVOR THIS ACTIVITY MAKING AS FAR EAST AS THE CO/KS STATE
LINE. WHILE MOST OF THIS ACTIVITY WILL BE TIED TO DAYTIME
HEATING...WAA OVERNIGHT AND NOSE OF LLJ COULD SUPPORT
THUNDERSTORM LINGERING LATE THIS EVENING...OR SHOWERS AFTER
MIDNIGHT AS INSTABILITY WANES. MID LEVELS ARE NOT PARTICULARLY
MOIST AND DESPITE VERY GOOD OVERNIGHT MOISTURE ADVECTION WITHIN
THE BOUNDARY LAYER CAP ABOVE THIS WOULD LIKELY LIMIT CONVECTIVE
POTENTIAL FOR ANY NON ELEVATED PARCELS. I KEPT SLIGHT CHANCE OF
THUNDERSTORMS IN THE EVENING WITH SHOWERS LINGERING AFTER
MIDNIGHT THROUGH THURSDAY MORNING. CONSIDERING THE NEAR SATURATED
BOUNDARY LAYER THE PRECIP SIGNAL IN GUIDANCE MAY ACTUALLY BE
DRIZZLE/FOG.
THURSDAY...NAM SOUNDINGS INDICATE POTENTIAL FOR LINGERING
STRATUS/DRIZZLE DURING THE DAY...HOWEVER OVERALL PATTERN SHOULD
SUPPORT CLEARING SKIES FROM THE WEST WITH WARMER CONDITIONS ACROSS
EASTERN COLORADO. A STRONGER SHORTWAVE TROUGH WILL BEGIN TO MOVE
INTO THE CWA FROM THE WEST WITH INCREASING THUNDERSTORM CHANCES
ONCE AGAIN IN EASTERN COLORADO WHERE BETTER INSTABILITY IS
ADVERTISED ALONG WITH STRONGER LIFT. CONFIDENCE WAS HIGH ENOUGH
TO KEEP CHANCE POPS IN PLACE LATE THURSDAY AFTERNOON. HIGH
TEMPERATURES THURSDAY WILL BE TRICKY AND HIGHLY DEPENDENT ON
STRATUS CLEARING. HIGHS NEAR 70F (MAINLY IN THE WEST) ARE POSSIBLE
WHERE BEST CHANCE FOR CLEAR SKIES IS CURRENTLY ANTICIPATED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 232 PM MDT WED APR 22 2015
THE UPPER RIDGE AXIS EXTENDING FROM THE GULF OF MEXICO THROUGH
THE NORTHERN HIGH PLAINS FLATTENS SOMEWHAT LATE THURSDAY INTO
THURSDAY NIGHT AS A SHORT WAVE TROUGH MOVES OUT OF THE SOUTHWEST
U.S. AND OVER THE CENTRAL PLAINS THURSDAY NIGHT. THE LEE SURFACE
TROUGH ALONG THE FRONT RANGE THAT DEEPENS IN RESPONSE TO THE UPPER
SHORT WAVE TROUGH HAS GOOD SOUTHEASTERLY FLOW AHEAD OF IT THAT
WILL BRING AMPLE GULF MOISTURE INTO THE REGION. SCATTERED STRONG
THUNDERSTORMS ARE POSSIBLE ACROSS THE FORECAST AREA THURSDAY NIGHT
AS A RESULT
THE MAIN UPPER TROUGH AXIS BEGINS TO LIFT OUT ACROSS THE
4-CORNERS REGION AND INTO THE CENTRAL AND SOUTHERN HIGH PLAINS
REGION BY FRIDAY AFTERNOON...WITH THE CENTROID OF THE TROUGH
MOVING OVER E CO/NW KS. DEWPOINTS IN THE 40S ACROSS THE AREA ON
THURSDAY AND THURSDAY NIGHT WILL INCREASE INTO THE LOWER 50S
ACROSS MAINLY THE EASTERN PORTION OF THE FORECAST AREA WHILE DRYER
AIR MOVES INTO THE WEST AS THE TROUGH MOVES EAST AND FORMS A
CLOSED LOW THAT MOVES ACROSS SOUTHERN KANSAS FRIDAY EVENING. WITH
AN INSTABILITY AXIS PRESENT OVER CENTRAL KANSAS...IT IS POSSIBLE
THE FORECAST AREA COULD SEE SOME STRONG TO SEVERE THUNDERSTORMS
MAINLY ACROSS THE FAR EASTERN SECTIONS THAT WILL BECOME MORE
WIDESPREAD AND STRONGER OVERNIGHT AS THEY MOVE FURTHER TO THE
EAST.
SHORT WAVE RIDGING IS EXPECTED BETWEEN THE EXITING TROUGH AS IT
LIFTS OUT OF THE REGION AND THE NEXT UPPER TROUGH THAT STARTS TO
DEEPEN OVER THE INTERMOUNTAIN WEST BETWEEN SATURDAY AND SATURDAY
EVENING. MODEL SOLUTIONS HAVE A LOW CENTER CONSOLIDATING AND
MOVING QUICKLY ACROSS NEW MEXICO SUNDAY EVENING. THEN AS MODEL
SOLUTIONS BEGIN TO DIVERGE TO A GREATER DEGREE...THE LOW SLOWS AND
ENDS UP SOMEWHERE OVER E OKLAHOMA/E TEXAS BY TUESDAY MORNING AS A
BLOCKING HIGH AMPLIFIES OVER THE WESTERN UNITED SATES. THAT RIDGE
MOVES OVER THE ROCKIES AND HIGH PLAINS REGION BY WEDNESDAY
EVENING. THE WEEKEND AND FIRST PART OF NEXT WEEK WILL REMAIN
UNSETTLED WITH SCATTERED THUNDERSTORMS POSSIBLE ACROSS THE AREA AS
THE LOW MOVES ACROSS THE SOUTHERN PLAINS. DRYER AND WARMER
CONDITIONS ARE ANTICIPATED BY MID-WEEK AS SURFACE HIGH PRESSURE
AND THE RIDGE ALOFT MOVE OVER THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1119 PM MDT WED APR 22 2015
MVFR TO IFR CONDITIONS FORECAST FOR THE 6Z TAFS. LOW STRATUS OVER
THE TX PANHANDLE IS FORECAST TO MOVE NORTH AND EXPAND IN COVERAGE
THROUGH THE REST OF THE NIGHT. AM THINKING THE VERY LOW STRATUS
WILL MOVE OVER KGLD FROM THE WEST...WHILE THE MVFR CEILINGS MOVE
UP FROM THE SOUTH. KMCK WILL BE IMPACTED BY THE LOWER CEILINGS A
FEW HOURS AFTER KGLD. EXPECT THE LOWEST CEILING DURING THE EARLY
MORNING. AFTER THAT THE WARMER TEMPERATURES SHOULD ALLOW CEILINGS
TO LIFT SOME IN THE LATE MORNING/AFTERNOON. THURSDAY EVENING
CEILINGS WILL AGAIN LOWER...REACHING IFR AT BOTH SITES BY
MIDNIGHT.
ASIDE FROM THE LOW CEILINGS FOG IS EXPECTED TO DEVELOP WEST OF
KGLD. CURRENTLY AM NOT ANTICIPATING ANY FOG TO MOVE OVER THE SITE.
LLWS WILL CONTINUE THROUGH THE NIGHT FOR BOTH SITES...COMING TO AN
END BY MID MORNING. BASED ON THE STRENGTH OF THE LOW LEVEL JET
THURSDAY EVENING...WOULD EXPECT LLWS TO RETURN TO BOTH SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1050 PM EDT FRI APR 24 2015
.UPDATE...
ISSUED AT 1050 PM EDT FRI APR 24 2015
DID AN UPDATE TO FINE TUNE THE POPS AND WX THROUGH THE REST OF THE
NIGHT BASED ON THE NEWEST HRRR AND NAM12 GUIDANCE AS WELL AS
CURRENT RADAR/OBS. ALSO MATCHED UP THE HOURLY T AND TD GRIDS PER
THE LATEST OBS AND TRENDS...WHERE A 5 DEGREE OR SO RIDGE TO VALLEY
SPLIT CURRENTLY EXISTS IN THE EAST. THESE GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS...ALONG WITH THE ISSUANCE OF A FRESHENED
SET OF ZONES.
UPDATE ISSUED AT 745 PM EDT FRI APR 24 2015
23Z SFC ANALYSIS SHOWS HIGH PRESSURE CLINGING ON IN THE FAR EAST
IN THE FACE OF AN APPROACHING AREA OF LOW PRESSURE...POISED TO
BRING SVR WX TO KY LATER ON SATURDAY...FROM THE WEST. THIS
WESTERN LOW/S WARM FRONT WILL SWING TOWARD THE AREA BY DAWN...
AFFECTING THE FAR SOUTHWEST INITIALLY THEN LIFTING DEEPER INTO
EAST KENTUCKY THROUGH MIDDAY SATURDAY. THE PCPN WILL HAVE A TOUGH
TIME REACHING THE GROUND ACROSS THE AREA THROUGH THE BULK OF THE
NIGHT AS THE VERY DRY LOWER ATMOSPHERE ONLY SLOWLY SATURATES...
DESPITE THE HRRR/NAM12 INDICATIONS. IN THIS ENVIRONMENT...EXPECT
THE EASTERN VALLEYS TO DROP OFF QUICKLY FOLLOWING SUNSET...EVEN
WITH THE THIN HIGH CLOUDS NOW IN PLACE OVERHEAD. ELSEWHERE...
TEMPERATURES WILL STAY UP THROUGH THE NIGHT...MUCH WARMER THAN
LAST NIGHT. HAVE UPDATED THE FORECAST TO NUDGE TEMPS IN THE
EASTERN VALLEYS DOWN A BIT...BUT EXPECT THEM TO MIX OUT BY DAWN AS
THE AIR SATURATES AND SHOWERS PUSH OVER THIS PART OF THE STATE. IN
ADDITION TO THE SEVERE THREAT FOR SATURDAY...THE LATEST MODEL RUNS
CONTINUE TO INDICATE THAT THERE IS ALSO A POTENTIAL FOR EXCESSIVE
RAINFALL DEPENDING ON THE TRACKS OF THE INDIVIDUAL CELLS AND/OR AN
MCS TRACKING ACROSS THE CWA IN THE AFTERNOON/EVENING THAT
CERTAINLY LOOKS POSSIBLE. THESE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI APR 24 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SURFACE HIGH PRESSURE
SLOWLY SLIDING OFF TO THE EAST TODAY. MID AND UPPER LEVEL CLOUD
COVER AT THIS TIME IS BEGINNING TO STREAM INTO EASTERN KENTUCKY
THIS EVENING. THIS IS AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
OUT WEST OVER THE CENTRAL PLAINS. CLOUD COVER OVER THE AREA WILL
LIKELY KEEP TEMPERATURES OVERNIGHT NEARLY UNIFORM WITH SOUTHERLY
WARM AIR MOVING INTO THE AREA THROUGH THE NIGHT. AT THIS TIME
OVERNIGHT...THE SURFACE LOW SLIDES EAST AS A WARM FRONT DEVELOPS
IN THE LOWER MS VALLEY AND MOVING NORTHEAST. THIS WILL BRING
SHOWERS INTO EASTERN KENTUCKY BY MIDNIGHT OR SHORTLY AFTERWARD.
HEADING INTO THE PREDAWN HOURS SATURDAY MORNING...THE MAIN SURFACE
LOW BEGINS TO MOVE INTO THE MID MS RIVER VALLEY AND INTO THE
MIDWEST WITH SOME INSTABILITY BEGINNING TO ENTER THE SOUTHWESTERN
COUNTIES AND THIS MAY LEAD TO A FEW EARLY NON SEVERE STORMS AND
MAY NEED TO ADD THUNDER TO THE TONIGHT PERIOD OF THE HWO. HEADING
INTO THE DAY ON SATURDAY...AFTER EARLIER RAINFALL HAS MOVED
THROUGH...SOME CLEARING SKIES AND RECOVERING ENERGY AND
DESTABILIZATION WILL THEN OCCUR WITH MOST UNSTABLE CAPE AROUND
1000 TO 1500 J/KG OVER SOUTHEASTERN KENTUCKY BY THE 18Z TIME
FRAME. THIS ALSO WITH SOME 60 KNOT SFC TO 6KM BULK SHEAR WILL BE
ENOUGH FOR SOME ROTATING STORMS TOMORROW AFTERNOON. DUE TO THIS
THREAT SPC HAS PUT THE SOUTHERN AREA IN AN ENHANCED THREAT OF
SEVERE WEATHER AND HAVE PUT THIS THREAT IN THE HWO AND MAY NEED AN
SPS TO HIGHLIGHT THE THREAT IN DETAIL. THE ONLY THREAT THAT IS A
BIT QUESTIONABLE TOMORROW WILL BE THE FLASH FLOOD THREAT. THOUGH
THE LAST HEAVY RAINFALL WAS LONG ENOUGH AGO THAT MOST PLACES HAVE
BEEN ALLOWED TO DRAIN AND DRY OUT. AS WELL...GREEN HAS GONE INTO
FULL SWING ACROSS THE AREA ALLEVIATING THE RUNOFF POTENTIAL.
HOWEVER...THE DISCRETE SUPER CELL POTENTIAL WILL ADD TO THE THREAT
OF FLASH FLOODING AS WELL AS IF AN MCS DEVELOPS BY LATE IN THE
EVENING ON SATURDAY. MAY NEED TO EVALUATE THIS DURING THE NEXT
MODEL RUN.
HEADING INTO SATURDAY EVENING...THE WARM FRONT MOVES THROUGH TO
THE NORTHEAST AND THEN THE SURFACE LOW TRACKS RIGHT ACROSS EASTERN
KENTUCKY WITH ANOTHER STRONG SHOT OF RAINFALL WHICH MAY BE ENOUGH
TO INITIATE THE FLASH FLOOD THREAT. HAVE ADJUSTED THE QPF FOR THE
00Z TO 06Z SUNDAY NIGHT PERIOD FOR THIS RAINFALL. RAINFALL AMOUNTS
WILL BE LESSENING BY 06Z TO 12Z RANGE SUNDAY NIGHT AS THE EVENT
WILL BE WINDING DOWN. FOR NOW...WILL HIGHLIGHT THE SEVERE AND
FLOOD THREAT IN THE HWO AND MAY NEED AN SPS TO FURTHER HIGHLIGHT
THIS. THE ZFP WILL HAVE SEVERE POTENTIAL AND HEAVY RAINFALL
MENTIONED AS WELL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 PM EDT FRI APR 24 2015
ANY REMAINING RAINFALL SHOULD BE WINDING DOWN BY SUNDAY MORNING AS
THE SFC LOW AND TRAILING COLD FRONT PUSH EAST OF KY. BEHIND THIS...
SKIES WILL GRADUALLY CLEAR AS DRY AIR FILTERS INTO THE REGION SUNDAY
EVENING...ALLOWING FOR EASTERN KENTUCKY TO RECEIVE A BREAK FROM THE
WET WEATHER TO START THE WORK WEEK. THIS IS DUE TO AN AREA OF HIGH
PRESSURE FORECAST TO MOVE SLOWLY ACROSS THE OH AND TN VALLEYS MONDAY
AND TUESDAY.
A LARGE CUTOFF LOW WILL THEN GRADUALLY MOVE EWD FROM TX ACROSS THE
SOUTHEASTERN US WEDNESDAY THROUGH THURSDAY. AS THE LOW MOVES EWD ITS
ENERGY IS FORECASTED TO GET WRAPPED INTO A DEEPENING NORTHERN STREAM
TROUGH. THE MODELS HAVE COME INTO BETTER AGREEMENT IN THE PAST
COUPLE OF RUNS WITH THE EVOLUTION OF THIS SYSTEM...WHERE THE ECMWF
SOLUTION HAS THE AREA OF LOW PRESSURE MOVING ALONG A TRACK SIMILAR
TO THAT OF THE GFS. HOWEVER...THE ECMWF SOLUTION KEEPS THE LOW CUT
OFF AND SEPARATE FROM THE NORTHERN STREAM TROUGH...CREATING QUITE A
BIT MORE PRECIP THAN THE GFS ACROSS EASTERN KENTUCKY THROUGH THE END
OF THE WORK WEEK. WITH UNCERTAINTY STILL EXISTING IN THIS PART OF
THE EXTENDED...DECIDED TO KEEP PRECIP IN DURING THE WED/THURS TIME
FRAME...AND STUCK CLOSE TO THE CR SUPERBLEND.
TEMPERATURES WILL GENERALLY BE BELOW NORMAL AND STAY IN THE 60S FOR
HIGHS AND IN THE 40S FOR LOWS THROUGHOUT THE EXTENDED. DURING THE
DRIER PERIODS...TEMPS WILL BE CLOSER TO NORMAL VALUES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 755 PM EDT FRI APR 24 2015
VFR CONDITIONS WILL CONTINUE TO BE THE RULE THROUGH EARLY SATURDAY
MORNING. RAIN WILL MOVE IN FROM THE SOUTHWEST OVERNIGHT AND
CIGS WILL LOWER TO MVFR TOWARD DAWN. ALTHOUGH A STORM OR TWO WILL
BE POSSIBLE WITH THE INITIAL ARRIVAL AND PROGRESS OF THE WARM
FRONT...THE BETTER THREAT WILL BE IN THE AFTERNOON. DURING THIS
TIME...THUNDERSTORMS ARE EXPECTED TO DEVELOP...SOME OF WHICH MAY
BECOME SEVERE. WITH THESE STORMS...CONDITIONS CAN BE TEMPORARILY
REDUCED TO NEAR ALTERNATE MINS OR BELOW DEPENDING ON THE STRENGTH
OF THE STORM. FOR THIS...WENT WITH VCTS BETWEEN 15 AND 00Z WITH
LATER UPDATES BETTER ABLE TO REFINE TIMING OF THE WORST
CONDITIONS. GUSTY WINDS ARE ALSO EXPECTED WITH ANY THUNDERSTORM
ACTIVITY. OTHERWISE...WINDS WILL BE LIGHT AND VARIABLE THROUGH
MOST OF THE PERIOD BEFORE SWITCHING TO THE SOUTH SOUTHEAST AND
PICKING UP TO BETWEEN 5 AND 10 KTS DURING THE AFTERNOON ON
SATURDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...SHALLENBERGER
LONG TERM...JVM
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1139 PM CDT WED APR 22 2015
.UPDATE...
ISSUED AT 1139 PM CDT WED APR 22 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.
UPDATE ISSUED AT 918 PM CDT WED APR 22 2015
NO CHANGE TO THE CURRENT FROST ADVISORY...ALTHOUGH...MIGHT SEE A
LITTLE COLDER TEMPERATURES OVER MCLEAN AND NORTHEAST MULHENBURG
COUNTIES IN WEST KENTUCKY. WILL NEED TO MONITOR OVERNIGHT.
THE NAM-WRF HIGH RESOLUTION GUIDANCE FAMILIES AND RAP GUIDANCE
APPEAR TO HAVE THE BEST HANDLE ON THE SENSIBLE WEATHER ELEMENTS
OVERNIGHT. THE VAST MAJORITY OF THE COLDER AND AND FROST POTENTIAL
SHOULD REMAIN ALONG AND NORTH OF THE CRAWLEY`S RIDGE/SHAWNEE HILLS
REGION.
MAIN ADJUSTMENT WAS TO SLOW THE DEGREE AND INTENSITY OF THE
RETURNING MID-LEVEL CLOUDS FROM ARKANSAS AND OKLAHOMA INTO
MISSOURI AND KENTUCKY OVERNIGHT. THIS SHOULD REDUCE ANY
SIGNIFICANT DISRUPTION IN RADIATIVE COOLING OVERNIGHT.
UPDATE ISSUED AT 632 PM CDT WED APR 22 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.
UPDATE ISSUED AT 438 PM CDT WED APR 22 2015
SORRY FOR THE LATE NOTICE.
TALKS WITH A STATE AGRONOMIST IN PARTS OF THE AREA EXPECTED TO
SEE PATCHY FROST AND TEMPERATURES IN THE 30S OVERNIGHT
NECESSITATED THE ISSUANCE OF A FROST ADVISORY FROM 2 AM TO 8 AM
CDT THURSDAY MORNING. MAIN CONCERN IS FOR PRIVATE AND COMMERCIAL
STRAWBERRY GROWERS...AS WELL AS PRIVATE AND COMMERCIAL PLANT
GROWERS WITH PLANTS VERY SENSITIVE TO FROST DEVELOPMENT.
FROST ADVISORY AREA OUTLINED IS ALONG AND NORTH OF A PIEDMONT
MISSOURI...VIENNA ILLINOIS...CALHOUN KENTUCKY LINE AT THIS TIME.
MAIN LIMITING FACTOR FOR COVERAGE IS THE AMOUNT OF EVAPORATION AT
THE GROUND SURFACE FROM THE INFLUX OF DRY AIR TODAY. HOWEVER...THERE
IS STILL ENOUGH ANTECEDENT MOISTURE FROM EARLIER RAIN
EVENTS...INCLUDING THE ONE LAST NIGHT TO ERR ON THE SIDE OF CAUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 116 PM CDT WED APR 22 2015
HIGH PRESSURE SHOULD RESULT IN QUIET WEATHER TONIGHT. MOS
CONTINUES TO SUGGEST MID TO UPPER 30S I-64 CORRIDOR OR JUST SOUTH.
PATCHY FROST WAS ALREADY IN PLACE. WILL MAINTAIN THIS THOUGH IT
LOOKS MARGINAL ESPECIALLY WITH FORECAST TEMP / DEW POINT SPREADS
WHAT THEY ARE. WILL MAINTAIN DRY WEATHER THURSDAY INTO THURSDAY
EVENING AS HIGH PRESSURE SLOWLY MOVES EAST. THE GFS AND NAM ARE IN
AGREEMENT THAT SOME LIGHT SHOWER/THUNDERSHOWER ACTIVITY COULD MAKE
IT INTO SEMO LATE THURSDAY NIGHT...WITH CHANCES INTO FRIDAY AS
WELL GRADUALLY SHIFTING EAST. CHANCES OF CONVECTION INCREASE
FRIDAY NIGHT AS THE MODELS CONTINUE TO ADVERTISE AN UPPER TROF AND
ASSOCIATED SURFACE LOW MOVING FROM THE PLAINS TOWARD THE UPPER
MIDWEST. USED A BLEND OF MOS GUIDANCE FOR TEMPS. MODEL PREFERENCE
WAS A GFS/NAM BLEND.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 116 PM CDT WED APR 22 2015
MEDIUM CONFIDENCE THROUGH THE WEEKEND WITH LOW CONFIDENCE WITH PATH
OF THE SYSTEM MID WEEK NEXT WEEK. LATEST MODELS RUNS INDICATE THE
SYSTEM NEXT WEEK WILL HIT US WHILE OTHERS SHOW A MORE SOUTHERLY PATH.
MAIN CONCERN WITH EXTENDED WILL BE WITH STRONG OR POSSIBLY SEVERE
STORMS SATURDAY AFTERNOON. THE ONE LIMITING FACTOR WILL BE AVAILABLE
MOISTURE WITH MOST MODELS NEAR ONE INCH OR LESS PW OR NEAR THE 75TH
PERCENTILE. OTHERWISE WINDS SHOW A GOOD SPEED SHEAR NOT SO MUCH ON
WITH DIRECTIONAL SHEAR I.E SRH <10M2/S2. HOWEVER WITH 850MB-500MB
LAPSE RATES 7+/KM AND MU CAPES BETWEEN 3K AND 4K ANY THING THAT DOES
GET GOING HAS THE POTENTIAL FOR SEVERE WIND AND WITH THE FREEZING
LEVEL NEAR 10K COULD NOT RULE OUT HAIL EITHER. CONSIDERING THE
SIGNIFICANT INSTABILITY IT WILL NOT TAKE AS MUCH SHEAR TO GET SOME
ROTATION.
OTHERWISE WEAK RIDGE WILL BUILD IN SUNDAY WITH THE NEXT SYSTEM ON
ITS HEELS. THE 00Z WED EU TAKES THIS ENERGY SOUTH OF THE FA THROUGH
THE LOWER TN VALLEY. THE 12Z EU TAKES BRINGS IT A LITTLE FARTHER
NORTH THROUGH OUR CWA TUE AND EXITS WED EARLY. THE CANADIAN IS MUCH
SLOWER WITH THIS SYSTEM. THE 06Z WED DGEX BRINGS THE CORE OF THE
UPPER LOW RIGHT THROUGH OUR CWA. SOME ENSEMBLES THE GEFS GEPS AND
EPS TAKE THE BRUNT OF THE SYSTEM SOUTH BUT STILL BRINGS PRECIP OVER
THE AREA. THUS WILL ALLOW EXTENDED INIT AND COLLABORATION CALCULATE
JUST WHAT POPS TO INCLUDE.
WILL START OUT ABOVE NORMAL TEMPS FOR THE WEEKEND AND COOL TO NEAR
NORMAL NEXT WEEK AS NEXT SYSTEM MOVES INTO THE REGION.
&&
.AVIATION...
ISSUED AT 1139 PM CDT WED APR 22 2015
VFR FORECAST TONIGHT. SURFACE HIGH PRESSURE IS SETTLING OVER THE
REGION...BUT MIXING WILL RESULT IN THE POTENTIAL FOR GUSTS INTO
THE TEENS AT KEVV AND KOWB THURSDAY. SOME MID-LEVEL CEILINGS WILL
BE POSSIBLE OVERNIGHT AND INTO THE MORNING AT KCGI AND KPAH...BUT
OTHERWISE SKIES WILL BE CLEAR.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR ILZ075>078-080>091.
MO...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR MOZ076-086-087-100.
IN...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR INZ081-082-085>088.
KY...FROST ADVISORY UNTIL 8 AM CDT THURSDAY FOR KYZ014-015-018-019.
&&
$$
UPDATE...DRS
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
950 PM CDT FRI APR 24 2015
.DISCUSSION...
SFC OBS FROM AROUND THE REGION SHOW THE ENTIRE FORECAST AREA IN A
SIGNIFICANT WARM SECTOR WITH DEWPOINTS RUNNING IN THE LOWER/MID
70S MOST LOCATIONS AS OF 02Z. 00Z KLCH SOUNDING SHOWED AN AIRMASS
PRIMED FOR CONVECTION WITH A PWAT VALUE RUNNING ABOUT 200 PERCENT
OF NORMAL...EXCELLENT INSTABILITY/LAPSE RATES/CAPE...AND GOOD
LOW-LEVEL SHEAR. WATER VAPOR IMAGERY SHOWS MULTIPLE DISTURBANCES
IN THE SRN STREAM FLOW ALOFT. ADD ALL THIS UP AND REGIONAL 88DS
CURRENTLY SHOW A FEW SHOWERS ONGOING ACROSS THE FORECAST AREA...
BUT A SIGNIFICANT SQUALL LINE/MCS CROSSING SRN AR/NWRN LA/NERN TX
ATTM. AS EXPECTED LATEST HRRR RUN HAS THIS EVENT PEGGED PRETTY
WELL AND IS IN LINE WITH INHERITED GRIDS/ZONES. LATEST SPC DAY 1
OUTLOOK HAS REDUCED OUR SEVERE RISK TO MARGINAL...BUT GIVEN SUCH
GOOD CONVECTIVE PARAMETERS NOTED EARLIER WILL MAINTAIN THE
INHERITED SEVERE MENTION. ELSEWHERE CHANGES WERE MINIMAL.
UPDATE OUT SHORTLY.
25
&&
.PREV DISCUSSION... /ISSUED 646 PM CDT FRI APR 24 2015/
AVIATION...THE SOUTHERN TERMINALS SHOULD HAVE MVFR CIGS LINGERING
THIS EVENING. TOWARDS MIDNIGHT A FAST MOVING SHORT WAVE COULD
PRODUCE SCATTERED TSTMS WITH IFR CIGS AT LCH, LFT, AND ARA. BPT
SHOULD STAY IFR CIGS WITH FOG DEVELOPING THIS EVENING. AEX WILL GO
FROM VFR TO IFR CIGS THIS EVENING. ALL THE TERMINALS SHOULD SEE
MVFR COME MORNING WITH THE POSSIBLILITY OF VFR LATE IN THE
AFTERNOON OR EARLY SATURDAY EVENING AS MOISTURE HEADS OUT TO THE
EAST.
JS
PREV DISCUSSION... /ISSUED 354 PM CDT FRI APR 24 2015/
DISCUSSION...
BUSY AFTERNOON TRACKING SEVERE SUPERCELL ACROSS SE TX INTO S
LA...PRODUCING DAMAGE ALONG MOST OF ITS PATH. ADDITIONAL SHRA/TSRA
TRIED TO DEVELOP BEHIND IT...BUT HAS SINCE DISSIPATED.
NOW...SVR WX THREAT IS NOT OVER YET. THE NEXT ROUND OF SHRA/TSRA
IS DEVELOPING ACROSS C AND NE TX NOW...AND IS EXPECTED TO MOVE SE
ACROSS OUR REGION LATER THIS EVENING ACROSS INLAND SE TX...AND THE
REMAINDER OF THE AREA AFTER MIDNIGHT INTO DAYBREAK. A SLIGHT RISK
OF SVR TSTM WILL CONTINUE WITH THESE CELLS...WITH HAIL...DAMAGING
WINDS...AND POSSIBLE TORNADOES.
GET A BRIEF REPRIEVE FROM THE SVR WEATHER LATER SAT INTO SUN. YET
ANOTHER STRONG UPPER LEVEL DISTURBANCE IS EXPECTED TO BRING ANOTHER
ROUND OF TSRA BY LATE MON/TUE...WITH A POSSIBILITY OF SVR WX...AS
OUTLINED IN THE DAY 4 SPC OUTLOOK.
BY LATE TUE INTO WED AND THE REMAINDER OF THE EXTENDED...COOLER
AND DRIER AIR BRING THE TEMPS BACK TO NEAR NORMAL WITH NO PRECIP
EXPECTED.
DML
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 71 88 68 90 / 60 40 10 10
LCH 72 83 70 86 / 60 50 10 10
LFT 73 85 70 88 / 50 50 10 10
BPT 72 84 69 85 / 60 50 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...04
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
738 PM CDT FRI APR 24 2015
.AVIATION...
FOR THE 25/00Z TAFS...A WIDE RANGE OF CIGS IN PLACE TO START THIS
TAF PERIOD WITH A WARM FRONT STRADDLING THE AR/LA BORDER AND THEN
SNAKING BACK NWWRD OVER EXTREME NE TX. THIS IS RESULTING IN LIFR
CIGS AND VSBYS AT TXK/ELD NORTH OF THE WARM FRONT WHILE MVFR/LOW
VFR CIGS ARE SEEN FARTHER SOUTH AT OUR REMAINING TAF SITES. A LINE
OF STRONG CONVECTION IS NOTED NEAR TXK EXTENDING SWWRD ALONG I-30
AS A MORE INTENSE LINE OF STORMS REMAINS TO OUR WEST NEAR THE DFW
METROPLEX. AVIATION CONCERNS ARE NUMEROUS WITH THESE STORMS THIS
EVENING TO INCLUDE SEVERE TURBULENCE...MIXED ICING...AND FREQUENT
LIGHTNING. WINDS ARE VEERING OFF THE DECK WITH MOSTLY S/SE WINDS
AT THE SFC AND BECOMING MORE W/SW ALOFT...SPEEDS NEAR AREAS OF
CONVECTION MAY EXCEED 50 KTS AT THE SFC. CONDITIONS WILL SLOWLY
IMPROVE AFTER MIDNIGHT THROUGH THE MORNING HOURS ON SATURDAY AS
CONVECTION MOVES EAST AND GRADUAL CLEARING OCCURS FROM W TO E.
/19/
&&
.PREV DISCUSSION... /ISSUED 507 PM CDT FRI APR 24 2015/
UPDATE...
JUST SENT OUT A QUICK UPDATE TO INCLUDE TORNADO WATCH 103 THROUGH
10 PM TONIGHT. STORMS TO DEVELOP ALONG AND SOUTH OF A BAROCLINIC
ZONE ORIENTED EAST TO WEST MAINLY ACROSS THE INTERSTATE 20
CORRIDOR. DAMAGING WINDS...HEAVY RAIN...HAIL...AND ISOLATED
TORNADOES POSSIBLE. /05/
PREV DISCUSSION... /ISSUED 326 PM CDT FRI APR 24 2015/
DISCUSSION...
LATEST SFC ANALYSIS SHOWING A DEEPENING SFC LOW ACROSS SE CO INTO
SW KS WITH A DRYLINE ACROSS THE TX/OK PNDL INTO W TX. A SOUTHEAST
FLANKING WARM FRONT EXTENDED FROM THE SFC LOW AND SNAKED SOUTH
AND EAST INTO CENTRAL OK TO JUST SOUTH OF DFW TO NEAR TYR TO ESF.
THIS WARM FRONT HAS MOVED VERY LITTLE TODAY ACROSS S/CENTRAL LA
BUT HAS SHOWN A GREATER TENDENCY TO MOVE NORTHWARD INTO NORTH
CENTRAL TEXAS OVER THE LAST COUPLE HOURS. CLOUD COVER REMAINS VERY
THICK AND ITS THIS CLOUD COVER THAT HAS TEMPERED DAYTIME HIGH
TEMPS TODAY. ITS ALSO THIS CLOUD COVER THAT HAS NOT ALLOWED FOR
MUCH IN THE WAY OF INSTABILITY. LATEST MESOANALYSIS ONLY SHOWING
CAPE VALUES NEAR 1000J/KG ALONG AND SOUTHWEST OF THE SLOWLY
RETURNING NORTHWARD WARM FRONT.
SUPERCELL THUNDERSTORM THAT FORMED SOUTH OF OUR AREA EARLIER TODAY
FORMED ALONG THE WARM FRONT AND THE BEST UPPER LEVEL SUPPORT WHICH
IS MEAGER AT BEST...EXISTS OUT WEST WHERE TORNADO WATCH #100 WAS
JUST ISSUED FOR PORTIONS OF CENTRAL AND N TX. THE LATEST WRF
OUTPUT HAS SHOWN A TENDENCY TO LIFT THE WARM FRONT TOO FAR NORTH
AND THUS ITS SOLUTION WAS DISCOUNTED. HAVE INSTEAD GONE WITH A
MODEL BLEND OF THE HRRR FOR THE VERY SHORT TERM...FOLLOWED BY A
GFS/ECMWF BLEND BEYOND TONIGHT. HAVING SAID THAT...THE LATEST HRRR
SHOWS CONVECTION DEVELOPING RAPIDLY NEAR AND NORTH OF THE I-20
CORRIDOR OF N TX LATER THIS EVENING WITH SOME OF THESE STORMS
LIKELY EXHIBITING DISCRETE CHARACTERISTICS AS THEY MOVE EASTWARD
INTO OUR NW ZONES. SOME OF THIS STRONG/SEVERE CONVECTION COULD
EVENTUALLY MOVE ITS WAY INTO NW LA LATE THIS EVENING/OVERNIGHT BUT
THE EVENTUAL STORM MODE SHOULD BE FOR A BROKEN LINE OF STRONG TO
SEVERE THUNDERSTORMS TO DEVELOP ACROSS THE REGION...RAPIDLY
EXPANDING AND SPREADING SOUTH AND EAST THROUGH THE NIGHT. DAMAGING
WIND GUSTS...LARGE HAIL AND ISOLATED TORNADOES WILL CONTINUE TO BE
A THREAT...WITH THE TORNADIC THREAT LIKELY ORIENTED NEAR WHERE THE
WARM FRONT SETS UP LATER THIS EVENING...SOMEWHERE ACROSS NE TX
INTO WEST CENTRAL OR NORTHWEST LOUISIANA.
THE LEAD SHORTWAVE EJECTS NORTHWARD INTO THE CENTRAL PLAINS
OVERNIGHT TONIGHT WITH NEAR ZONAL FLOW IN ITS WAKE SETTING UP
ACROSS THE SOUTHERN PLAINS. THIS SHOULD RESULT IN A MUCH DRIER DAY
ON SATURDAY BUT A STRONG PRESSURE GRADIENT WILL EXIST ACROSS THE
REGION AS WELL. STRONG SOUTHWEST WINDS AND EVENTUAL SUNSHINE WILL
ALLOW FOR SFC TEMPS TO WARM WELL INTO THE 80S ON SAT AS WELL AS
SUN WITH SOME LOCATIONS LIKELY FLIRTING WITH THE 90 DEGREE MARK.
MOISTURE BEGINS TO RETURN QUICKLY BACK INTO THE REGION FROM THE
SOUTH DURING THE DAY SUNDAY INTO SUNDAY NIGHT AS YET ANOTHER UPPER
TROUGH DIGS INTO THE SOUTHWEST CONUS AND CUTS OFF ACROSS THE FOUR
CORNERS REGION LATE SUNDAY NIGHT. THIS RETURNING MOISTURE AND
INSTABILITY WILL LIKELY RESULT IN ANOTHER RISK OF STRONG TO SEVERE
THUNDERSTORMS ACROSS OUR REGION MONDAY INTO MONDAY NIGHT WITH THE
UPPER TROUGH ONLY MAKING SLOW EASTWARD PROGRESS INTO CENTRAL OK BY
TUE. THE GOOD NEWS IS BY THIS TIME...WE SHOULD BEGIN TO SEE DRY
SLOTTING ALONG THE SOUTHERN FLANK OF THE CLOSED LOW WHICH SHOULD
RESULT IN DRIER CONDITIONS TUESDAY AND ESPECIALLY WEDNESDAY
THROUGH THE END OF THE WORK WEEK AS AS UPPER LEVEL RIDGING BEGINS
TO TAKE OVER FROM THE WEST.
PRELIMS TO FOLLOW...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 69 89 64 89 / 60 20 0 10
MLU 70 87 66 87 / 60 30 10 10
DEQ 62 86 51 85 / 80 10 0 10
TXK 68 87 60 85 / 80 10 0 10
ELD 68 85 60 84 / 60 20 0 10
TYR 69 89 63 88 / 60 10 0 10
GGG 68 88 63 88 / 60 10 0 10
LFK 70 89 65 89 / 60 30 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
723 PM EDT FRI APR 24 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM EDT FRI APR 24 2015
FLOW ALOFT BRIEFLY HAS BECOME WESTERLY WHICH IS ALLOWING WARM
ADVECTION OCCURRING NORTH OF WEAK SFC WARM FRONT OVER SOUTHERN
MINNESOTA TO AFFECT FAR WESTERN GREAT LAKES. LOW-LEVELS BLO H85 PER
12Z SOUNDINGS FM GRB/INL/MPX REMAIN QUITE DRY...BUT MOISTURE AND
WARM ADVECTION MAINLY AT H7 IS DRIVING AREA OF SCT LIGHT SHOWERS
OVER NORTHWEST WI. EVEN SOME SNOW WAS REPORTED IN NORTHEAST
MINNESOTA EARLIER TODAY AS TEMPS WERE IN THE 30S AS THE PRECIP BEGAN.
BASED ON WHERE RAP/NAM SHOW NOSE OF H7 MOISTURE TRANSPORT INTO THIS
EVENING...SOME OF THE SHRA OVER NORTHWEST WI MAY CLIP SW UPR
MICHIGAN THROUGH MIDNIGHT. GREATEST CHANCES FM IRONWOOD TO IRON
RIVER. WEAK FORCING ALOFT AND PERSISTENT DRY LOW-LEVELS WILL
PROHIBIT THE PRECIP FM MAKING IT VERY FAR TO THE NORTH AND EAST OF
THOSE AREAS. LATEST HRRR MODEL RUNS ARE PICKING UP ON THIS...SHOWING
ANY SIMULATED REFLECTIVITY AT 1KM OF NOTE FADING AS IT MOVES INTO
SCNTRL UPR MICHIGAN. AS TEMPS COOL ENOUGH IN BLYR AFTER SUNSET...MAY
SEE RAIN TRY TO TURN TO SNOW BRIEFLY BEFORE THE WANING FORCING
ALLOWS THIS PRECIP TO END. NOT EXPECTING ANYTHING MORE THAN A
COATING OF SNOW ACCUMULATION IF IT OCCURS AT ALL. TEMPS TONIGHT WILL
BE COOLEST IN THE EAST /UPR TEENS TO LOW 20S/ CLOSER TO SFC HIGH AND
WHERE SKIES STAY MOSTLY CLEAR. ELSEWHERE EXPECT READINGS IN UPR 20S
TO MID 30S...WARMEST WEST.
MID CLOUDS GRADUALLY FADE AWAY ON SATURDAY AS SFC HIGH PRESSURE
BUILDS IN FM HUDSON BAY. NORTHERLY GRADIENT WINDS TIED INTO THE HIGH
WILL KEEP AREAS NEAR LK SUPERIOR SHORE STUCK IN THE 30S DESPITE THE
INCREASING SUNSHINE. WARMEST TEMPS INTO THE LOW 50S WILL BE ALONG WI
BORDER AND ALSO NEAR LK MICHIGAN WITH NORTH WINDS COMING OFF THE
LAND OF EAST HALF OF UPR MICHIGAN.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 342 PM EDT FRI APR 24 2015
SAT NIGHT AND SUN...SFC RIDGING AND DRY WEATHER IS EXPECTED TO
DOMINATE THE WRN GREAT LAKES AS A MID LEVEL RIDGE BUILDS TOWARD MN
AND NW ONTARIO AND TROUGH LINGERS FROM NRN NEW ENGLAND THROUGH THE
ERN GREAT LAKES. WITH LIGHT NE TO N LOW LEVEL FLOW...TEMPS WILL
REMAIN BELOW NORMAL...ESPECIALLY NEAR LAKE SUPERIOR WHERE HIGHS WILL
REACH ONLY INTO THE LOWER 40S. READINGS TO AROUND 50 WILL PREVAIL
OVER THE SOUTH HALF.
THE SFC HIGH WILL CONTINUE TO RIDGE S INTO UPPER MI ON MON...SO MON
WILL BE SIMILAR TO SUN. HOWEVER...WITH THE PRES GRADIENT WEAKENING
AND A SLIGHT MODERATION OF AIR MASS...MAX TEMPS MON SHOULD BE
SEVERAL DEGREES HIGHER THAN SUN...ESPECIALLY IN THE INTERIOR.
MEDIUM RANGE MODELS INDICATE A SHORTWAVE MOVING ACROSS THE NRN
PLAINS MON NIGHT. AS MID/UPPER RIDGE BEGINS BUILDING OVER THE
ROCKIES...THIS WAVE MAY END UP DIVING SE OR S TOWARD A SRN TROF OVER
TX/LWR MISSISSIPPI VALLEY REGION PER 12Z RUNS OF GFS AND GEM AND
23/12Z ECMWF...RESULTING IN CONTINUED DRY WEATHER HERE. THE 24/00Z
AND 24/12Z RUNS OF THE ECMWF HAVE TRENDED STRONGER WITH THE
SHORTWAVE SHOWING A MORE AGGRESSIVE EASTWARD PROGRESSION BEFORE
DIVING THE SHORTWAVE SE. THIS SOLN MAY RESULT IN SOME LIGHT SHRA
SPREADING INTO UPPER MI TUE INTO WED MORNING. GIVEN THAT LATEST
ECMWF STILL SHOWS THE MORE AGGRESSIVE EASTWARD PROGRESSION WITH
SHORTWAVE WILL MAINTAIN SLIGHT CHC POPS FOR SHRA OVER THE CWA TUE
INTO WED. CAA IN N-NE FLOW AHEAD OF BUILDING SFC HIGH FM CANADA AS
DEPICTED BY 12Z ECMWF WL KEEP TEMPS COOLER WED INTO WED NIGHT
PROBABLY SIMILAR TO EXPECTED BELOW NORMAL READINGS THIS WEEKEND.
THU-FRI...SFC HIGH PRES BUILDS BACK OVER THE REGION AND SINCE BOTH
12Z GFS AND ECMWF HAVE TRENDED FARTHER NORTH WITH SERIES OF
SHORTWAVES MOVING ACROSS SCNTRL CANADA EXPECT GENERALLY DRY
CONDITIONS TO PREVAIL. GENERAL TREND OF 00Z MEDIUM RANGE GUIDANCE IS
FOR UPSTREAM MID-UPR LVL RIDGING OVER THE WRN CONUS TO BE A BIT MORE
PRONOUNCED WHICH RESULTS IN A SHARPER NW FLOW DEVELOPING INTO THE
UPPER LAKES. THIS WOULD TEMPER THE WARMUP INTO THE WRN GREAT LAKES
FOR LATE WEEK AND MAY RESULT IN TEMPS CLOSER TO NORMAL INSTEAD OF
ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 723 PM EDT FRI APR 24 2015
A DRY NE FLOW OUT OF HI PRES OVER NW ONTARIO WL RESULT IN VFR
CONDITIONS AT ALL 3 TAF SITES THIS FCST PERIOD. WHILE THERE COULD BE
SOME -SHRA AT IWD THIS EVNG CLOSER TO A WARM FNT IN THE UPR
MIDWEST...THE LLVL DRY AIR SHOULD MAINTAIN VFR CIGS/VSBY EVEN IF
SOME -RA FALLS AT THIS LOCATION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 241 PM EDT FRI APR 24 2015
HIGH PRESSURE WILL BE THE DOMINANT WEATHER FACTOR OVER THE UPPER
GREAT LAKES THIS WEEKEND AND THROUGH MUCH OF NEXT WEEK. OVERALL THE
WINDS WILL STAY AT OR BLO 20 KTS. THE ONE MAIN EXCEPTION WILL BE
TONIGHT AND SATURDAY OVER WESTERN LK SUPERIOR WHERE EAST TO
NORTHEAST WINDS OF 20-25 KTS WITH GUSTS TO AROUND 30 KTS ARE
EXPECTED AS STRONGER HIGH PRESSURE AREA INITIALLY BUILDS OVER THE
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
319 AM EDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 319 AM EDT THU APR 23 2015
NAM SHOWS A 500 MB TROUGH OVER THE ROCKIES AND ANOTHER OVER NEW
ENGLAND 12Z FRI. THE TROUGH OVER THE ROCKIES MOVES INTO THE CENTRAL
PLAINS ON FRI AND GETS ABSORBED INTO THE TROUGH IN NEW ENGLAND ON
SAT. MOST OF THE PCPN WITH THIS SYSTEM STAYS TO THE WEST AND SOUTH
OF THE AREA...BUT DID PUT SOME SLIGHT CHANCE POPS IN FOR THE FAR
WEST FRI NIGHT. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE
GOING FORECAST FOR TEMPERATURES OR WEATHER AND KEPT IT DRY FOR LATE
FRI NIGHT INTO SAT NIGHT. QUIET AND COOL WEATHER FOR THIS FORECAST
PERIOD.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE
EASTERN U.S. WITH A DEEPER TROUGH IN THE ROCKIES AND A RIDGE OVER
THE PLAINS 12Z SUN. UPPER PATTERN CHANGES LITTLE FOR 12Z MON. A
RIDGE BUILDS INTO THE WESTERN U.S. 12Z TUE. A TROUGH IS POISED TO
DROP INTO THE UPPER GREAT LAKES 12Z TUE WHICH DOES MOVE INTO THE
AREA ON WED. LOOKS DRY FOR SUN AND MON WITH A SLOW WARMING
TREND...BUT TEMPERATURES WILL REMAIN BELOW NORMAL FOR THIS FORECAST
PERIOD. HAVE SOME SLIGHT CHANCE POPS IN FOR THE WEST HALF OF THE
AREA MON NIGHT THROUGH WED AS A SFC FRONT AND UPPER TROUGH ARE
NEARBY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 120 AM EDT THU APR 23 2015
EXPECT PREDOMINANT MVFR CONDITIONS WITH COLD...MOIST NW FLOW OF AIR
AROUND DEEP LOW PRES IN SE CANADA OVERNIGHT EVEN THROUGH SOME
LINGERING SNOW SHOWERS COULD REDUCE VSBY BRIEFLY TO IFR AT IWD/CMX.
IMPROVEMENT TO VFR CONDITIONS IS EXPECTED THURSDAY MORNING WITH THE
CLOSER APPROACH OF SFC HIGH PRES AND DRIER AIR UNDER LARGE SCALE
SUBSIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR THIS EVENING. LOW PRESSURE ACROSS
JAMES BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS
LAKE SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 344 PM EDT WED APR 22 2015
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO/
POCKET OF H5 TEMPS NEAR -30C CENTERED OVER ONTARIO TO THE SW OF
JAMES BAY DOWNSTREAM OF HI AMPLITUDE RDG OVER THE ROCKIES. DEEP
MOIST CYC NW FLOW ARND THE CLOSED LO CONTINUES TO IMPACT UPR MI...
DRAWING UNSEASONABLY CHILLY AIR /H85 TEMPS AS LO AS -12 TO -14C THAT
ARE SUFFICIENTLY COLD FOR LES/ INTO THE AREA. THE RESULT HAS BEEN
NMRS SN SHOWERS THAT HAVE BEEN EXACERBATED OVER LAND WITH DAYTIME
HEATING EVEN IN THE ABSENCE OF SGNFT LARGER SCALE FORCING/DEEP LYR
QVECTOR CNVGC.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/SN AMOUNTS
ESPECIALLY TNGT AS UPR LO DRIFTS SLOWLY TO THE E. TEMPS WL REMAIN
BLO NORMAL THRU THU.
TNGT...UPR LO IS FCST TO DRIFT SLOWLY TO THE E...ALLOWING FOR SLOWLY
RISING H5 HGT/WEAKENING LLVL CYC FLOW. ALTHOUGH SOME GENERAL LARGER
SCALE SUBSIDENCE IS FCST TO DOMINATE...H85 TEMPS REMAINING AS LO AS
ABOUT -13C IN THE PRESENCE OF SOME LINGERNING DEEP MSTR/NOCTURNAL
COOLING WL BE SUFFICIENT TO MAINTAIN LES IN THE FAVORED NW WIND SN
BELTS OVER THE ERN CWA. EXPECT UP TO A COUPLE INCHES OF SN ACCUM IN
THIS AREA. OVER THE W...WARMING H85 TEMPS TO ARND -10C/ LOWERING
SUBSIDENCE INVRN UNDER THE GREATER HGT RISES SHOULD TEND TO CAUSE
THE SN SHOWERS TO DIMINISH IN THAT AREA. HOWEVER...THE PERSISTENT
UPSLOPE NW FLOW AND LINGERING UPSLOPE FLOW WL ALLOW FOR AT LEAST
SOME SCT SN SHOWERS EVEN IN THAT AREA.
THU...PERSISTENT HGT RISES AND SUBSIDENCE/TENDENCY FOR THE LLVL FLOW
TO BECOME MORE ACYC AS WELL AS SOME LLVL DRYING IN THE PRESENCE OF
DAYTIME HEATING WL DIMINISH THE SN SHOWERS W-E. FCST SDNGS INDICATE
THERE WL BE SOME SUNSHINE IN THE AFTN AS WELL WITH HI PRES RDG FCST
TO BLD INTO THE WRN CWA LATER IN THE DAY. TEMPS SHOULD REBOUND INTO
THE 40S OVER THE INTERIOR W AND SCENTRAL AWAY FM LK MODERATION WITH
H85 TEMPS PROGGED TO REACH NEAR -6C ALONG THE WI BORDER BY 00Z FRI.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM EDT WED APR 22 2015
EVEN AS A SFC RIDGE MOVES IN FROM THE W THU NIGHT...ISOLATED SNOW
SHOWERS SHOULD LINGER INTO THE NIGHT IN NW WIND SNOWBELTS NEAR ERN
LAKE SUPERIOR. THIS AS 850MB TEMPS WILL BE AROUND -10C UNDER NW
WINDS. BY FRI MORNING...THE INCREASING INFLUENCE OF THE RIDGE AND
THE WARNING AIRMASS OVERHEAD WILL MAKE FOR A DRY DAY ACROSS THE U.P.
/RULING AT THE 12Z/22 GFS AS AN OUTLIER WITH THE LIGHT PRECIP OVER
THE FAR W/. CLEARING SKIES FROM W TO E THU NIGHT INTO FRI WILL LEAD
TO MIN TEMPS THU NIGHT IN THE TEENS OVER THE INTERIOR W AND IN THE
20S ELSEWHERE. HIGHS ON FRI WILL RANGE FROM THE MID 30S NEAR
CENTRAL/ERN LAKE SUPERIOR TO THE UPPER 40S ALONG THE WI BORDER.
THE WEEKEND LOOKS DRY...SUNNIER AND WARMER AS A SFC LOW SLIDES WELL
S OF THE CWA WITH SFC AND UPPER RIDGING REMAINING OVER THE CWA.
850MB TEMPS HOVERING AROUND 0C SAT AND SUN COMBINED WITH THE PARTLY
CLOUDS SKIES WILL MAKE FOR HIGHS IN THE 40S TO LOW 50S...COOLEST
NEAR LAKE SUPERIOR OVER AND E OF THE KEWEENAW DUE TO E-NE FLOW OFF
THE LAKE. THE RELATIVELY WEAK FLOW AND MORE LIMITED CLOUD COVER WILL
ALLOW MIN TEMPS SAT AND SUN NIGHTS TO BE IN THE MID 20S INLAND TO
LOW 30S ELSEWHERE.
MON ALSO LOOKS FREE OF PRECIP AS RIDGING WEAKENS BUT REMAINS
OVERHEAD. THE ECMWF SUGGEST THE UPPER LOW CURRENTLY IMPACTING THE
REGION MAY RETROGRADE BACK TOWARD THE AREA AFTER SITTING OVER NEW
ENGLAND...BUT THAT WOULD ONLY LEAD TO LIGHT PRECIP OVER THE E IF
THAT DID OCCUR...BUT WILL LEAVE PRECIP OUT OF THE FORECAST FOR NOW.
850MB TEMPS INCREASE A COUPLE OF DEGREES ON MON...BUT TEMPS SHOULD
BE SIMILAR TO SUN AS CLOUD COVER WILL BE INCREASED.
NOT REAL CONFIDENT FOR TUE AND WED AS MODELS SHOW UPPER LEVEL
IMPULSES MOVING THROUGH THE REGION...BUT THERE IS QUITE A BIT OF RUN
TO RUN AND MODEL TO MODEL DISCONTINUITY DURING THIS TIME AS A MORE
SIGNIFICANT PATTERN SHIFT MAY BE STARTING. PRECIP CHANCES ARE
GREATER THAN FRI-MON...BUT NOT HIGH BY ANY MEANS. TEMPS ON TUE LOOK
TO BE SIMILAR TO TUE...BUT MAY COOL DOWN A BIT ON WED. JUST USED A
CONSENSUS OF GUIDANCE FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 120 AM EDT THU APR 23 2015
EXPECT PREDOMINANT MVFR CONDITIONS WITH COLD...MOIST NW FLOW OF AIR
AROUND DEEP LOW PRES IN SE CANADA OVERNIGHT EVEN THROUGH SOME
LINGERING SNOW SHOWERS COULD REDUCE VSBY BRIEFLY TO IFR AT IWD/CMX.
IMPROVEMENT TO VFR CONDITIONS IS EXPECTED THURSDAY MORNING WITH THE
CLOSER APPROACH OF SFC HIGH PRES AND DRIER AIR UNDER LARGE SCALE
SUBSIDENCE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT WED APR 22 2015
A FEW NW WINDS GUSTING TO 30 TO NEAR 35KT GALES WILL REMAIN POSSIBLE
OVER N AND CENTRAL LAKE SUPERIOR THIS EVENING. LOW PRESSURE ACROSS
JAMES BAY WILL FILL LATE TONIGHT AND THURSDAY. THE TROUGH ACROSS
LAKE SUPERIOR THIS MORNING...EXTENDING FROM THE JAMES BAY LOW...WILL
SLOWLY BE REPLACED BY A RIDGE. THIS RIDGE WILL REMAIN IN PLACE FROM
FRIDAY THROUGH SUNDAY...EXTENDING FROM STRONG HIGH OVER FAR NORTHERN
CANADA AND GREENLAND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1021 PM CDT FRI APR 24 2015
.UPDATE...LATEST HIRES HRRR GUIDANCE SHOWS THE BOWING LINE MOVING
THROUGH THE NW LOUISIANA AND SW ARKANSAS PUSHING INTO MAINLY THE
DELTA REGION LATER TONIGHT THEN DEVELOPING SOUTHEASTWARD. SPC HAS
EXTENDED OUR WESTERN AREAS INTO A TORNADO WATCH UNTIL 4 AM. SO HAVE
ADJUSTED ZONES AND GRIDS ACCORDINGLY. UPPER 00Z PLOTS SHOWS GOOD
DIVERGENCE OVER THE REGION EVEN WITH GOOD JET ENERGY AND STRONG
SHEAR. MEANWHILE ON THE SURFACE THE WARM FRONT WAS PUSHING NORTH.
WILL SEND UP A 06Z BALLOON TO SEE HOW THE ATMOSPHERE HAS EVOLVED
AHEAD OF THE BOWING LINE./17/
./PREVIOUS DISCUSSION...445 PM CDT FRI APR 24 2015
.DISCUSSION...MORNING CONVECTIVE COMPLEXES HAVE DIMINISHED AS THEY
HAVE MOVED EAST BUT HAVE BROUGHT SOME RAIN TO THE REGION THROUGH THIS
AFTERNOON. ADDITIONAL SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO
MOVE INTO THE REGION FROM THE WEST BUT THESE ARE MUCH MORE SCATTERED.
DESPITE THE DRIER AIR THAT WAS IN PLACE ACROSS THE REGION THIS
MORNING...LOW LEVEL MOISTURE HAS RETURNED TO THE REGION WITH
DEWPOINTS ACROSS SOUTHERN AND CENTRAL SECTIONS OF THE REGION IN THE
MID TO UPPER 60S. THIS IS THANKS TO A NORTHWARD MOVING WARM FRONT
FROM THE COAST. NORTH OF THE WARM FRONT...DEWPOINTS ARE IN THE MID
50S BUT EXPECT THAT THESE SHOULD INCREASE THROUGH THE REMAINDER OF
THE EVENING AS SOME MODELS EVEN SHOW UP TO 70 DEGREE DEWPOINTS ACROSS
PORTIONS OF THE REGION. MODELS CONTINUE TO INDICATE THAT ADDITIONAL
STORMS WILL DEVELOP ACROSS THE DELTA AS THE EVENING
PROGRESSES....PARTICULARLY AFTER 8-10PM. AT THIS POINT VERTICAL
TOTALS AND DEEP LAYER SHEAR INCREASE THROUGH THE EVENING(WITH SHEAR
VALUES APPROACHING 60-70KTS) AND SHOULD BE PLENTY SUFFICIENT FOR
DAMAGING WINDS...HAIL AND TORNADOES. IT APPEARS THAT THE LATEST RUNS
OF THE HRRR MIGHT HAVE THE BEST HANDLE ON THE SITUATION AS A SMALL
AREA OF LOW PRESSURE DEVELOPS IN THE DELTA IN ASSOCIATION WITH THE
APPROACHING SQUALL LINE. IT BRINGS THE LINE THROUGH MOSTLY THE
NORTHERN SECTIONS OF MY CWA FROM ABOUT 03-10Z WITH SEVERAL LEWP
STRUCTURES AND IT DOES APPEAR THAT LOCATIONS ALONG AND NORTH OF I-20
HAVE THE GREATEST SEVERE POTENTIAL...ESPECIALLY IN THE DELTA. WE
HAVE GONE AHEAD AND UPGRADED OUR HWO PRODUCTS ESPECIALLY IN THE DELTA
WHERE A SIGNIFICANT THREAT FOR SEVERE WEATHER IS EXPECTED WITH
GREATER THAN 75MPH WINDS AND STRONG TORNADOES POSSIBLE. /28/
ON SATURDAY THE OVERNIGHT THUNDERSTORM ACTIVITY WILL LEAVE A
BOUNDARY SET UP OVER THE AREA AND THE GFS/ECMWF INDICATE AT LEAST
ISOLATED TO SCATTERED THUNDERSTORM POTENTIAL SATURDAY AFTERNOON.
WITH GOOD LAPSE RATES OF AROUND 6.5 C/KM...LARGE HAIL LOOKS LIKE IT
WILL BE THE MAIN CONCERN ALONG WITH DAMAGING WIND GUSTS. STILL CANT
COMPLETELY RULE OUT A TORNADO BUT HAIL AND WIND SHOULD BE THE MAIN
CONCERN. EXPECT ALL OF THE THUNDERSTORM POTENTIAL TO END EARLY
SATURDAY EVENING WITH CLEARING SKIES SATURDAY NIGHT AS DRIER AIR
BUILDS IN./15/
THE UPPER LEVEL PATTERN ACROSS THE CONUS LOOKS TO GET QUITE
AMPLIFIED BY SUNDAY AS THE PREVIOUS TROUGH ENERGY BRINGING INCLEMENT
WEATHER IN THE SHORT TERM BECOMES PART OF A CONSOLIDATED AND LARGE
UPPER LOW OFF THE NORTHEAST COAST AND MORE ENERGY DIGS TOWARD THE
SOUTHERN PLAINS. SHORT WAVE RIDGING IN BETWEEN THESE TROUGHS WILL BE
OVER THE LOWER MS VALLEY WITH A COLD FRONT PREVIOUSLY EXPECTED TO
COME INTO THE NORTH SUNDAY LIKELY DELAYED UNTIL LATE IN THE DAY
ACCORDING TO LATEST MODEL CONSENSUS. THIS SHOULD SPELL A VERY WARM
AND MOSTLY SUNNY SUNDAY FOR MUCH OF THE REGION WITH HIGHS IN THE MID
TO UPPER 80S.
BY LATER SUNDAY NIGHT AND ESPECIALLY MONDAY DISTURBANCES SHOULD
START EJECTING OUT OF THE APPROACHING PLAINS UPPER
LOW...UNDERCUTTING HIGH LATITUDE BLOCKING IN THE PERSISTENTLY ACTIVE
SOUTHERN BRANCH OF THE JET STREAM. LATEST MODEL SOLUTIONS ARE
HINTING IN THIS PATTERN THAT BAROCLINICITY AND INSTABILITY FOCUSED
FROM THE RED RIVER VALLEY TOWARD THE GULF COAST WILL PROVIDE A FOCUS
FOR THUNDERSTORM COMPLEXES RIDING SOUTHEAST AND BLENDED GUIDANCE IS
CATCHING ON TO THIS. MONDAY AND MONDAY NIGHT POPS ARE MOST STRONGLY
FOCUSED IN SOUTHERN (AND ESPECIALLY SOUTHWESTERN) ZONES AND IT IS
QUITE POSSIBLE POPS COULD TREND EVEN MORE WEIGHTED TOWARD THE COAST.
IT IS NOT UNTIL TUESDAY OR WEDNESDAY WHEN THE UPPER LOW SHOULD COME
OVER THE REGION AND POSITIVELY FORCE SOLID RAIN AND EMBEDDED STORM
OPPORTUNITIES ACROSS THE WHOLE OF THE LOWER MS VALLEY.
MUCH DRIER WEATHER LOOKS TO MOVE IN FOR MIDDLE OF THE WEEK INTO THE
WEEKEND AS UPPER RIDGING TAKES HOLD ONCE AGAIN. /BB/
&&
.AVIATION...AS A WARM FRONT PUSHES NORTHEAST ACROSS THE AREA LATER
TONIGHT...EXPECT INCREASING CHANCES FOR TSRA AND LOWER
CIGS...ESPECIALLY ALONG AND NORTHWEST OF THE HEZ-JAN-GTR CORRIDOR IN
THE 03Z-12Z TIME FRAME. DRIER AIR WILL BECOME TO MOVE BACK IN
SATURDAY FROM THE WEST...BUT THERE WILL BE LINGERING CHANCES FOR
TSRA ESPECIALLY IN THE HBG/PIB AREA. OTHERWISE...EXPECT VFR
CONDITIONS TO PREVAIL THROUGH THE AFTERNOON INTO THE EVENING HOURS.
/EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 70 85 67 87 / 71 40 8 7
MERIDIAN 68 84 66 86 / 66 50 11 7
VICKSBURG 70 87 66 87 / 74 26 8 9
HATTIESBURG 71 85 68 89 / 42 45 10 8
NATCHEZ 71 85 68 86 / 53 31 7 7
GREENVILLE 67 86 63 82 / 97 22 5 9
GREENWOOD 67 86 63 83 / 96 34 8 10
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/28/15/BB/EC
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
712 PM CDT FRI APR 24 2015
.UPDATE...LATEST HIRES HRRR GUIDANCE SLOWS THINGS DOWN A LITTLE FOR
THIS EVENING. THIS IS REFLECTED BY AREA RADARS. IT STILL SHOWS A
GOOD LEWPING BOWING SEGEMENT PASSING THROUGH THE NORTH HALF FOR
LATER TONIGHT. INSTABILITY WILL GRADUALLY INCREASE WITH THE GOOD
LOWER AND UPPER JET ENERGY AND DEEP STRONG SHEAR. SO HAVE REMOVED
ALL SHOWERS AND KEPT IT ALL CONVECTIVE THROUGH SATURDAY. ALSO HAVE
LOWERED POPS SOME FOR THIS EVENING. WITH THE SLIGHTLY COOLER TEMPS
IN THE NORTH HAVE MODIFIED OVERNIGHT LOWS SLIGHTLY. OTHERWISE THE
REST OF THE FORECAST APPEARS TO BE ON TRACK AS WE WATCH THE STORM
CROSS NORTH CENTRAL LOUISIANA./17/
./PREVIOUS DISCUSSION...445 PM CDT FRI APR 24 2015
.DISCUSSION...MORNING CONVECTIVE COMPLEXES HAVE DIMINISHED AS THEY
HAVE MOVED EAST BUT HAVE BROUGHT SOME RAIN TO THE REGION THROUGH THIS
AFTERNOON. ADDITIONAL SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO
MOVE INTO THE REGION FROM THE WEST BUT THESE ARE MUCH MORE SCATTERED.
DESPITE THE DRIER AIR THAT WAS IN PLACE ACROSS THE REGION THIS
MORNING...LOW LEVEL MOISTURE HAS RETURNED TO THE REGION WITH
DEWPOINTS ACROSS SOUTHERN AND CENTRAL SECTIONS OF THE REGION IN THE
MID TO UPPER 60S. THIS IS THANKS TO A NORTHWARD MOVING WARM FRONT
FROM THE COAST. NORTH OF THE WARM FRONT...DEWPOINTS ARE IN THE MID
50S BUT EXPECT THAT THESE SHOULD INCREASE THROUGH THE REMAINDER OF
THE EVENING AS SOME MODELS EVEN SHOW UP TO 70 DEGREE DEWPOINTS ACROSS
PORTIONS OF THE REGION. MODELS CONTINUE TO INDICATE THAT ADDITIONAL
STORMS WILL DEVELOP ACROSS THE DELTA AS THE EVENING
PROGRESSES....PARTICULARLY AFTER 8-10PM. AT THIS POINT VERTICAL
TOTALS AND DEEP LAYER SHEAR INCREASE THROUGH THE EVENING(WITH SHEAR
VALUES APPROACHING 60-70KTS) AND SHOULD BE PLENTY SUFFICIENT FOR
DAMAGING WINDS...HAIL AND TORNADOES. IT APPEARS THAT THE LATEST RUNS
OF THE HRRR MIGHT HAVE THE BEST HANDLE ON THE SITUATION AS A SMALL
AREA OF LOW PRESSURE DEVELOPS IN THE DELTA IN ASSOCIATION WITH THE
APPROACHING SQUALL LINE. IT BRINGS THE LINE THROUGH MOSTLY THE
NORTHERN SECTIONS OF MY CWA FROM ABOUT 03-10Z WITH SEVERAL LEWP
STRUCTURES AND IT DOES APPEAR THAT LOCATIONS ALONG AND NORTH OF I-20
HAVE THE GREATEST SEVERE POTENTIAL...ESPECIALLY IN THE DELTA. WE
HAVE GONE AHEAD AND UPGRADED OUR HWO PRODUCTS ESPECIALLY IN THE DELTA
WHERE A SIGNIFICANT THREAT FOR SEVERE WEATHER IS EXPECTED WITH
GREATER THAN 75MPH WINDS AND STRONG TORNADOES POSSIBLE. /28/
ON SATURDAY THE OVERNIGHT THUNDERSTORM ACTIVITY WILL LEAVE A
BOUNDARY SET UP OVER THE AREA AND THE GFS/ECMWF INDICATE AT LEAST
ISOLATED TO SCATTERED THUNDERSTORM POTENTIAL SATURDAY AFTERNOON.
WITH GOOD LAPSE RATES OF AROUND 6.5 C/KM...LARGE HAIL LOOKS LIKE IT
WILL BE THE MAIN CONCERN ALONG WITH DAMAGING WIND GUSTS. STILL CANT
COMPLETELY RULE OUT A TORNADO BUT HAIL AND WIND SHOULD BE THE MAIN
CONCERN. EXPECT ALL OF THE THUNDERSTORM POTENTIAL TO END EARLY
SATURDAY EVENING WITH CLEARING SKIES SATURDAY NIGHT AS DRIER AIR
BUILDS IN./15/
THE UPPER LEVEL PATTERN ACROSS THE CONUS LOOKS TO GET QUITE
AMPLIFIED BY SUNDAY AS THE PREVIOUS TROUGH ENERGY BRINGING INCLEMENT
WEATHER IN THE SHORT TERM BECOMES PART OF A CONSOLIDATED AND LARGE
UPPER LOW OFF THE NORTHEAST COAST AND MORE ENERGY DIGS TOWARD THE
SOUTHERN PLAINS. SHORT WAVE RIDGING IN BETWEEN THESE TROUGHS WILL BE
OVER THE LOWER MS VALLEY WITH A COLD FRONT PREVIOUSLY EXPECTED TO
COME INTO THE NORTH SUNDAY LIKELY DELAYED UNTIL LATE IN THE DAY
ACCORDING TO LATEST MODEL CONSENSUS. THIS SHOULD SPELL A VERY WARM
AND MOSTLY SUNNY SUNDAY FOR MUCH OF THE REGION WITH HIGHS IN THE MID
TO UPPER 80S.
BY LATER SUNDAY NIGHT AND ESPECIALLY MONDAY DISTURBANCES SHOULD
START EJECTING OUT OF THE APPROACHING PLAINS UPPER
LOW...UNDERCUTTING HIGH LATITUDE BLOCKING IN THE PERSISTENTLY ACTIVE
SOUTHERN BRANCH OF THE JET STREAM. LATEST MODEL SOLUTIONS ARE
HINTING IN THIS PATTERN THAT BAROCLINICITY AND INSTABILITY FOCUSED
FROM THE RED RIVER VALLEY TOWARD THE GULF COAST WILL PROVIDE A FOCUS
FOR THUNDERSTORM COMPLEXES RIDING SOUTHEAST AND BLENDED GUIDANCE IS
CATCHING ON TO THIS. MONDAY AND MONDAY NIGHT POPS ARE MOST STRONGLY
FOCUSED IN SOUTHERN (AND ESPECIALLY SOUTHWESTERN) ZONES AND IT IS
QUITE POSSIBLE POPS COULD TREND EVEN MORE WEIGHTED TOWARD THE COAST.
IT IS NOT UNTIL TUESDAY OR WEDNESDAY WHEN THE UPPER LOW SHOULD COME
OVER THE REGION AND POSITIVELY FORCE SOLID RAIN AND EMBEDDED STORM
OPPORTUNITIES ACROSS THE WHOLE OF THE LOWER MS VALLEY.
MUCH DRIER WEATHER LOOKS TO MOVE IN FOR MIDDLE OF THE WEEK INTO THE
WEEKEND AS UPPER RIDGING TAKES HOLD ONCE AGAIN. /BB/
&&
.AVIATION...AS A WARM FRONT PUSHES NORTHEAST ACROSS THE AREA LATER
TONIGHT...EXPECT INCREASING CHANCES FOR TSRA AND LOWER
CIGS...ESPECIALLY ALONG AND NORTHWEST OF THE HEZ-JAN-GTR CORRIDOR IN
THE 03Z-12Z TIME FRAME. DRIER AIR WILL BECOME TO MOVE BACK IN
SATURDAY FROM THE WEST...BUT THERE WILL BE LINGERING CHANCES FOR
TSRA ESPECIALLY IN THE HBG/PIB AREA. OTHERWISE...EXPECT VFR
CONDITIONS TO PREVAIL THROUGH THE AFTERNOON INTO THE EVENING HOURS.
/EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 70 85 67 87 / 71 40 8 7
MERIDIAN 68 84 66 86 / 66 50 11 7
VICKSBURG 70 87 66 87 / 74 26 8 9
HATTIESBURG 71 85 68 89 / 42 45 10 8
NATCHEZ 71 85 68 86 / 53 31 7 7
GREENVILLE 67 86 63 82 / 97 22 5 9
GREENWOOD 67 86 63 83 / 96 34 8 10
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/28/15/BB/EC
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
836 PM MDT FRI APR 24 2015
.UPDATE...
THE MAJORITY OF THUNDERSTORM ACTIVITY HAS ENDED ACROSS THE AREA.
LATEST SOUNDING FROM THE HRRR DOE NOT SHOW MUCH...IF
ANY...INSTABILITY OVERNIGHT. SO HAVE REMOVED ANY MENTION OF
THUNDER AFTER MIDNIGHT...AND LEFT ONLY ISOLATED THUNDER UNTIL
MIDNIGHT. REST OF THE FORECAST LOOKS GOOD. REIMER
&&
.SHORT TERM...VALID FOR SAT AND SUN...
AN UPPER LOW AND TROUGH MOVING ONTO THE OREGON AND NORTHERN
CALIFORNIA COASTS WILL CONTINUE TO BRING A SOUTHWEST FLOW ALOFT
ALONG WITH SOME WEAK UPPER LEVEL DIVERGENCE ACROSS OUR FORECAST
AREA FOR THE REMAINDER OF THIS AFTERNOON INTO THE OVERNIGHT HOURS.
A LIGHT EASTERLY SURFACE FLOW WILL CONTINUE AS WELL WHICH WILL
HELP TO KEEP DEWPOINTS IN THE UPPER 20S TO LOWER 30S. MOSTLY
CLOUDY SKIES HAVE MOVED INTO OUR WESTERN ZONES THIS AFTERNOON BUT
SUNNY TO PARTLY SUNNY SKIES ACROSS OUR SOUTH AND EAST THIS MORNING
INTO THE AFTERNOON HAS ALLOWED CONDITIONS TO BE MORE UNSTABLE
WHICH HAS RESULTED IN A FEW THUNDERSTORMS TO DEVELOP OVER THE BIG
HORN AND PRYOR MOUNTAINS...AS WELL AS NUMEROUS AREAS OF CU
DEVELOPING ACROSS THE EAST. UPPER LEVEL WINDS ARE FAIRLY WEAK AND
THUNDERSTORMS ARE BEHAVING ACCORDINGLY AS SLOW MOVERS AND PULSER
TYPE STORMS.
AN UPPER LEVEL DISTURBANCE WILL APPROACH THE FORECAST AREA
TONIGHT. THIS IN COMBINATION WITH A COLD FRONT THAT WILL MOVE
THROUGH LATE TONIGHT INTO SATURDAY MORNING WILL RESULT IN THE
LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS ACROSS OUR WESTERN AREAS
THIS EVENING SPREADING EAST OVERNIGHT INTO EARLY SATURDAY MORNING.
WINDS WILL BECOME NORTH/NORTHWEST LATE TONIGHT INTO SATURDAY
MORNING BEHIND THE FRONT WITH JUST LINGERING SHOWER CHANCES
THROUGH THE DAY. HOWEVER...LIKELY POPS WILL CONTINUE THROUGH THE
DAY ACROSS THE EAST AS THE FRONT AND UPPER LEVEL DISTURBANCE MOVES
INTO THE DAKOTAS.
THE WEST COAST TROUGH MOVES INTO THE CENTRAL AND NORTHERN ROCKIES
SATURDAY AND SATURDAY NIGHT WITH THE STRONGEST DYNAMICS MOVING
WELL TO OUR SOUTH ACROSS UTAH AND COLORADO. THE 700MB LOW ALSO
MOVES SOUTH ACROSS NORTHERN UTAH INTO SOUTHWEST WYOMING. AS A
RESULT...MODELS KEEP THE HEAVIEST PRECIP SOUTH OF OUR AREA ACROSS
WYOMING AND COLORADO. WILL STILL CONTINUE WITH LIKELY POPS LATE
SATURDAY NIGHT INTO SUNDAY BUT OVERALL AMOUNTS ARE NOT EXPECTED TO
BE OVERLY IMPRESSIVE. IN ADDITION...DYNAMIC COOLING WITH THIS
SYSTEM ALSO LOOKS TO STAY TO OUR SOUTH WITH SNOW LEVELS FOR ARE
MOUNTAINS ABOUT 7000FT AND ABOVE. ALTHOUGH THERE WILL STILL BE THE
POSSIBILITY OF A RAIN/SNOW MIX LATE SATURDAY NIGHT INTO SUNDAY
MORNING FOR THE RED LODGE AND SHERIDAN FOOTHILLS LOCATIONS.
SHOWERS WILL SLOWLY DECREASE FROM WEST TO EAST SUNDAY AFTERNOON
BUT LIKELY POPS WILL REMAIN ACROSS THE EASTERN AREAS THROUGH
SUNDAY NIGHT. HIGH TEMPERATURES WILL BE QUITE A BIT COOLER
TOMORROW AND SUNDAY WITH READINGS SATURDAY A GOOD 10 DEGREES
COOLER THAN TODAY WITH MOST LOCATIONS IN THE MIDDLE 50S TO LOWER
60S...WITH 50S ON SUNDAY. HOOLEY
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
LITTLE IN THE WAY OF CHANGES TO THE EXTENDED FORECAST PERIOD...AS
A STRONG UPPER LEVEL LOW WILL PREVAIL ACROSS THE REGION.
A FEW SHOWERS MAY LINGER IN THE EAST MONDAY MORNING...BUT SHOULD
CLEAR BY MID DAY AS THE UPPER LEVEL RIDGE BUILDS INTO THE REGION.
THE MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH REGARD TO
AMPLITUDE OF THE RIDGE...AS WELL AS ITS PERSISTENCE THROUGH AT
LEAST WEDNESDAY NIGHT. THIS WILL RESULT IN WARM AND DRY CONDITIONS
FOR THE FIRST HALF OF THE WORK WEEK. TEMPERATURES WILL BE IN THE
60S MONDAY...70S TUESDAY...AND CLIMB TO AROUND 80 FOR WEDNESDAY
THROUGH FRIDAY.
MODELS ALSO AGREE ON A DISTURBANCE SLIDING INTO
THE REGION WEDNESDAY NIGHT OR THURSDAY MORNING...BUT HAVE
SIGNIFICANTLY DIFFERENT READS ON WHAT FORM THAT WAVE WILL TAKE AS
WELL AS SPEED AND TRACK. HAVE CONTINUED WITH INHERITED SLIGHT POPS
FOR THURSDAY THROUGH FRIDAY...BUT THIS DEVELOPING SYSTEM WILL NEED
SOME ATTENTION AS GETS CLOSER IN TIME. AAG
&&
.AVIATION...
SCATTERED SHOWERS WILL CONTINUE THROUGHOUT THE NIGHT WITH AN
ISOLATED THUNDERSTORM POSSIBLE BEFORE 06Z. THE GREATEST COVERAGE
OF SHOWERS IS EXPECTED TO BE ALONG AND WEST OF A KSHR-KBIL-ROUNDUP
LINE. THE SHOWERS WILL SPREAD FURTHER EAST TOWARD KMLS AND KBHK
LATE TONIGHT INTO SATURDAY MORNING. LOCAL MVFR TO IFR CONDITIONS
WILL BE POSSIBLE WITH ANY SHOWER/THUNDERSTORM. OTHERWISE...VFR
CONDITIONS WILL PREVAIL. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 044/059 039/056 038/067 042/074 046/080 048/080 049/078
73/W 46/W 31/B 00/U 00/U 11/B 22/W
LVM 037/055 034/052 031/068 037/075 041/079 046/076 047/072
74/T 66/W 30/B 00/U 00/U 12/W 22/W
HDN 042/062 039/056 038/067 036/075 040/080 044/080 045/080
64/W 36/W 41/B 00/U 00/U 11/B 22/W
MLS 044/057 038/059 039/066 037/072 041/079 044/078 047/076
47/W 24/W 41/B 00/U 00/U 11/U 12/W
4BQ 041/056 039/056 039/063 036/070 040/076 044/077 045/074
37/W 47/W 72/W 00/U 00/U 11/U 11/B
BHK 040/056 039/056 037/061 035/067 037/075 042/076 044/074
27/W 66/W 73/W 00/U 00/U 11/U 11/B
SHR 043/057 037/053 035/064 035/071 038/076 044/076 045/075
43/W 47/W 61/B 00/U 00/U 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
802 AM MDT THU APR 23 2015
.UPDATE...
MADE A QUICK UPDATE TO STRETCH POPS FARTHER EAST THIS MORNING.
WEAK BAND OF SHOWERS FROM LIVINGSTON TO JUST NORTH OF COLUMBUS
HOLDING ON. THOUGH HRRR DOES WEAKEN THEM IN TIME...THEY HAVE BEEN
HOLDING ON TO THEIR STRENGTH THE LAST COUPLE OF HOURS. TWH
&&
.SHORT TERM...VALID FOR TDY AND FRI...
EARLY MORNING AREA OF SHOWERS MOVING THROUGH NORTHERN PORTIONS OF
SOUTHEAST MONTANA PRODUCING ONLY LIGHT RAIN BUT EXPECT ACTIVITY TO
PERSIST FOR A WHILE AFTER 12Z. FLATTER FLOW BEHIND THIS WAVE IS
CLEARING OUT SOUTH CENTRAL MONTANA BUT WATER VAPOR IMAGERY SHOWS A
DECENT AMOUNT OF MOISTURE IS LINGERING IN PLACE BEHIND THE SYSTEM.
NOT MUCH IN THE WAY OF FORCING TODAY BUT PRECIPITABLE WATERS .50
TO .75 WILL COMBINE WITH DIURNAL WARMING TO ALLOW FOR SOME SHOWER
ACTIVITY WITH THE MOUNTAINS BEING FAVORED. A THUNDERSTORM OR TWO
CANNOT BE RULED OUT BUT ANY CELL MOVEMENT SHOULD BE PRETTY SLOW SO
EXPECT MOST CELLS TO REMAIN AS RAIN SHOWERS. TEMPERATURES WILL BE
COOLER TODAY WITH THE FLATTER FLOW ALOFT.
BROADER HEIGHT FALLS UPSTREAM OVERNIGHT OVER WASHINGTON AND BC
TURN THE FLOW ALOFT SOUTHWESTERLY. THE INITIAL HEIGHT RISES OVER
THE AREA ASSOCIATED WITH THIS PROCESS WILL STABILIZE THE AIRMASS
AFTER MIDNIGHT WHICH WILL BRING CLEARING AND ALLOW FOR A BIT
COOLER TEMPERATURES OVERNIGHT.
FRIDAY THE FLOW ALOFT BECOMES SLIGHTLY DIFFLUENT OVER THE AREA
WHICH ALLOWS A SURFACE TROUGH TO DEVELOP ALONG THE FOOTHILLS. THIS
ALLOWS MOISTURE TO DEEPEN AND SET UP A BETTER CHANCE FOR SHOWERS
OVER THE MOUNTAINS. BY AFTERNOON AND EVENING A DISTURBANCE ROTATES
THROUGH SOUTHWEST MONTANA AND THIS BRINGS A MUCH BETTER CHANCE FOR
SHOWER ACTIVITY WITH INCREASING MID LEVEL WINDS. THIS WILL SPEED
UP STORM MOVEMENT AND ALLOW SHOWERS TO BEGIN SPREADING INTO THE
PLAINS. AT THE SAME TIME A COOL FRONT BEGINS MOVING ACROSS THE
AREA FRIDAY NIGHT WHICH PROVIDES A BETTER TRIGGER FOR SHOWERS AND
ISOLATED THUNDERSTORMS. HAVE INCREASED POPS ESPECIALLY FOR FRIDAY
NIGHT AFTER MIDNIGHT AS MODELS ARE PRETTY CONSISTENT WITH THIS
EVOLUTION AND SREF PLUMES ARE ADVERTISING .30 INCHES OF PRECIP FOR
BILLINGS AREA. BORSUM
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
SATURDAY WILL BEGIN WITH A WEAK SHORTWAVE IN OUR CENTRAL PARTS
MOVING TOWARD THE EAST IN SW FLOW ALOFT. GOOD CHANCE OF SHOWERS
ALONG INVERTED TROF ACROSS OUR EAST AND HAVE RAISED POPS.
SUBSIDENCE ALONG WITH LOW LEVEL DRYING WILL LIMIT PCPN CHANCES
BEHIND THIS WAVE...UNTIL UPPER DIVERGENCE BEGINS TO INCREASE AGAIN
IN OUR FAR WEST PER APPROACHING DEEPER LOW. HAVE REDUCED POPS AND
TAKEN OUT THUNDER ACROSS OUR CENTRAL PARTS ON SATURDAY. THIS
INCLUDES BILLINGS WHICH SHOULD ONLY SEE A CHANCE OF SHOWERS EARLY
IN THE DAY. TEMPS WILL BE SEASONAL WITH HIGHS IN THE UPPER 50S TO
MID 60S.
LOW OVER THE PAC NW SATURDAY WILL DRIVE TOWARD THE CENTRAL AND
SOUTHERN ROCKIES SUNDAY. MODELS IN SOME DISAGREEMENT IN PATH OF
MID LEVEL LOW AND PCPN CHANCES IN OUR CWA...WITH THE GFS SHOWING A
FAIRLY WET UPSLOPE EVENT TRANSITIONING TO OUR SOUTHEAST SATURDAY
NIGHT THROUGH SUNDAY. THE ECMWF SUGGESTS WE WILL BE MORE DOMINATED
BY THE NORTHERN WEAKER SPLIT WITH LESS LOW LEVEL MOISTURE
ADVECTION...AND IS THUS DRIER. WILL LEAN TOWARD THE CONSENSUS/
SREF AND KEEP HIGH POPS ESPECIALLY FOR OUR SOUTHERN TIER THESE
PERIODS. PCPN AMOUNTS ON THE ORDER OF A HALF INCH POSSIBLE IN
THESE AREAS AND COULD SEE SOME WET SNOWFALL FOR THE FOOTHILLS
INCLUDING LIVINGSTON...RED LODGE AND STORY AS 850MB TEMPS MAY
APPROACH +1C WITH DYNAMIC COOLING...WARMER IF THE EC VERIFIES OF
COURSE. DO NOT SEE A HIGH IMPACT THREAT HERE JUST SOME MUCH-NEEDED
PCPN AND SOME SNOW OVER THE NORTH ASPECTS OF THE MOUNTAINS. SYSTEM
WILL CONTINUE TO DRIVE SOUTHWARD AND OUR PCPN POTENTIAL WILL
DIMINISH SUNDAY NIGHT AS DRIER NW FLOW TAKES OVER. TEMPS ON SUNDAY
LOOK TO BE THE COOLEST OF THE EXTENDED PERIOD WITH UPPER 40S AND
50S FOR HIGHS.
UPPER RIDGE WITH ABOVE NORMAL HEIGHTS WILL BRING US DRY AND WARMER
WEATHER MONDAY THROUGH WEDNESDAY...THOUGH MODELS DIVERGE HORRIBLY
WITH RESPECT THE OVERALL AMPLITUDE OF THE FLOW ACROSS THE EASTERN
PACIFIC AND CONUS. CONFIDENCE IS HIGH THAT OUR WX WILL BE DRY.
BIGGER QUESTION IS HOW WARM IT WILL GET AND HOW FAST. GFS SUGGESTS
A COUPLE DAYS OF EAST WINDS WHEREAS THE FLATTER ECMWF CREATES
STRONGER DOWNSLOPE WARMING. EITHER WAY WE SHOULD SEE TEMPS GET
BACK INTO THE 70S BY THE MIDDLE OF NEXT WEEK...WITH 80S ALSO
POSSIBLE.
JKL
&&
.AVIATION...
ISOLATED TO SCATTERED SHOWERS WILL AFFECT THE REGION TODAY AND
TONIGHT WITH LOCAL MVFR AND SOME MOUNTAIN OBSCURATIONS POSSIBLE.
VFR FLIGHT CONDITIONS WILL PREVAIL OTHERWISE. THERE IS POTENTIAL
FOR A FEW TSTMS THIS AFTERNOON AND EVENING. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 065 044/069 043/063 039/055 038/068 042/072 044/076
2/T 22/T 63/W 66/W 31/B 00/B 00/U
LVM 065 038/064 037/059 035/053 031/067 037/073 039/075
4/T 34/T 64/T 76/W 31/B 00/B 00/B
HDN 068 040/072 040/065 039/054 038/067 037/073 040/076
2/T 21/B 54/W 56/W 41/B 00/B 00/U
MLS 067 038/071 041/062 040/056 039/066 037/070 041/073
2/T 11/B 37/W 46/W 51/B 10/B 00/U
4BQ 069 040/070 041/062 040/055 039/063 037/069 039/072
2/T 21/B 25/T 47/W 61/B 10/B 00/U
BHK 065 035/067 039/059 040/055 038/062 037/065 037/069
2/T 11/B 17/W 46/W 52/W 10/B 00/B
SHR 065 039/067 039/061 037/050 036/064 036/069 038/072
2/T 23/T 42/W 47/W 51/B 00/B 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
631 PM CDT FRI APR 24 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 250 PM CDT FRI APR 24 2015
THE PRIMARY FORECAST CONCERNS IN THE SHORT TERM ARE POTENTIAL FOR
SEVERE STORMS...MAINLY BEFORE 08Z...AND THEN RAIN CHANCES LINGERING
ON SATURDAY. SOME AREAS OF HEAVY RAIN ARE POSSIBLE TONIGHT.
SURFACE ANALYSIS AT MID AFTERNOON SHOWED TWO LOW PRESSURE CENTERS.
ONE WAS OVER WESTERN KANSAS AND THE OTHER WAS OVER CENTRAL SOUTH
DAKOTA. THE FIRST LOW WILL STRENGTHEN OVERNIGHT AND TRACK INTO
NORTHWEST MISSOURI BY DAYBREAK SATURDAY. MODEST LOW LEVEL MOISTURE
HAD MOVED NORTHWARD INTO THE FORECAST AREA WITH DEWPOINTS IN THE
LOWER TO MID 50S AT MANY LOCATIONS. LATEST SPC MESOSCALE ANALYSIS
SHOWED THE MIXED LAYER CAPE AXIS EXTENDING FROM CENTRAL KANSAS TO
SOUTHWEST NEBRASKA THEN INTO NORTH CENTRAL NEBRASKA. EFFECTIVE
SHEAR VALUES AS OF 19Z WERE MOSTLY LESS THAN 30 KNOTS LOCALLY.
MID LEVEL LAPSE RATES WERE MOSTLY 7.5 TO 8.5 DEGREES C PER KM.
EXPECT THAT STORMS WILL INCREASE IN COVERAGE TO OUR WEST AND SOUTH
LATER THIS AFTERNOON AND EVENING...THEN CONTINUE FOR THE OVERNIGHT.
RECENT HRRR AND RAP MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THAT.
SEVERE THREAT APPEARS TO BE MAINLY HAIL AND THAT MAINLY IN OUR
FAR SOUTHWEST COUNTIES AS STORMS LIFT/MOVE NORTHEAST FROM KANSAS.
THERE IS ALSO SOME THREAT OF HAIL WITH STORMS THAT MAY AFFECT
PARTS OF NORTHEAST NEBRASKA MAINLY BEFORE MIDNIGHT. HIGHEST
POTENTIAL FOR PCPN AMOUNTS OF AN INCH OR MORE IS ACROSS SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA...BUT ALL AREAS COULD SEE LOCALLY
HEAVY RAIN.
ON SATURDAY...PCPN SHOULD DECREASE IN COVERAGE AND INTENSITY DURING
THE MORNING. SOME LIGHT SHOWERS COULD LINGER INTO THE AFTERNOON...
MAINLY IN SOUTHWEST IOWA. OTHERWISE...A WEAK RIDGE OF HIGH PRESSURE
WILL BUILD INTO THE FORECAST AREA WITH NORTHERLY WINDS. CLOUDS ARE
EXPECTED TO LIMIT HEATING...SO KEPT MOST HIGHS SATURDAY IN THE MID
50S TO LOWER 60S.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 250 PM CDT FRI APR 24 2015
THIS PERIOD SHOULD BE MAINLY DRY WITH MODERATING TEMPERATURES. A
CLOSED LOW AT 500 MB IS EXPECTED TO BE OVER THE TEXAS PANHANDLE AT
THE START OF THIS PERIOD. THIS WILL TRACK OFF TO THE NORTHEAST AND
OPEN UP THROUGH MID WEEK AS A RIDGE BUILDS IN FROM THE NORTHWEST.
THE EARLY PART OF THE WEEK MAY NOT BE COMPLETELY DRY...BUT AT THIS
TIME PCPN CHANCES SEEMED TO BE 14 PERCENT OR LESS FOR ANY GIVEN
PERIOD. HIGHS WILL START OUT IN THE 60S MONDAY/TUESDAY...THEN WARM
TO THE 70S BY THURSDAY AND POSSIBLY NEAR 80 BY FRIDAY.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 627 PM CDT FRI APR 24 2015
CONDITIONS WILL REMAIN VARIABLE THROUGH MUCH OF THE TAF PERIOD AS
A LARGE AREA OF LOW PRESSURE MOVES ACROSS THE REGION. FOR THE
EVENING...SCATTERED SHOWERS ARE EXPECTED TO MOVE INTO KLNK AND
KOMA AND WILL CONTINUE INTO THE OVERNIGHT HOURS. SOUTHEASTERLY SFC
WINDS WILL BECOME NORTHEAST OVERNIGHT AS THE LOW BEGINS TO PASS
OVER THE AREA. SCATTERED SHOWERS SHOULD SUBSIDE AT THE TAF SITES
BY SUNRISE SATURDAY MORNING...WITH LOW CLOUDS LINGERING THROUGH A
GOOD PART OF THE DAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
321 PM CDT THU APR 23 2015
.SYNOPSIS...
ISSUED AT 320 PM CDT THU APR 23 2015
SPLIT UPPER LEVEL PATTERN OVER THE WESTERN HALF OF THE CONUS...BROAD
CYCLONIC FLOW TO THE EAST. A SHORTWAVE RIDGE WAS TRANSLATING EAST
ACROSS THE CENTRAL PLAINS...IN ADVANCE OF A STRONG PV MAX SLOWLY
MOVING NORTHEASTWARD ACROSS THE DESERT SOUTHWEST. THE ASSOCIATED
HEIGHT FALLS WITH THIS PATTERN WERE SUPPORTING THE GRADUAL DEEPENING
OF A LEE SIDE SFC TROUGH FROM NORTHEAST COLORADO THROUGH THE WESTERN
NEBRASKA PANHANDLE. EAST OF THIS TROUGH WINDS WERE BREEZY OUT OF THE
SOUTH...TRANSPORTING LOW LEVEL MOISTURE INTO THE CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU APR 23 2015
CUMULUS CLOUDS AND A FEW SHOWERS AND THUNDERSTORMS HAVE ALREADY
DEVELOPED JUST WEST OF THE CWA EARLY THIS AFTERNOON. HI-RES MODELS
HAVE CONSISTENTLY SHOWN THE THUNDERSTORM ACTIVITY INCREASING IN
COVERAGE AND MOVING EAST LATER THIS AFTERNOON AS A WEAK UPPER LEVEL
SHORTWAVE EJECTS OUT OF THE CENTRAL ROCKIES. THE BEST CHANCES
THROUGH THE EVENING WILL GENERALLY BE CONFINED TO THE PANHANDLE AND
SOUTHWEST NEBRASKA. AS FAR AS STORM INTENSITY...MLCAPE IN THE
VICINITY OF THE SFC TROUGH WILL NEAR 1000 J/KG BY LATER AFTERNOON
AND EARLY EVENING. STEEP MID LEVEL LAPSE RATES OF 7-8 C/KM ARE ALSO
IN PLACE OVER THE HIGH PLAINS. A STORM OR TWO REACHING STRONG TO
SEVERE LIMITS WITH HAIL AND GUSTY WINDS CANNOT BE RULED OUT...MAINLY
WEST OF HWY 61. THE ABILITY FOR STORMS TO SUSTAIN THEMSELVES AND
REMAIN ORGANIZED IS IN QUESTION DUE RATHER WEAK MID LEVEL FLOW AND
DEEP LAYER SHEAR ONLY AROUND 25 TO 30 KTS. THE MORE FAVORABLE
ENVIRONMENT WILL REMAIN TO THE SOUTH WHERE FASTER FLOW ALOFT AND
BETTER SHEAR PROFILES RESIDE.
THUNDERSTORM CHANCES MOVE EAST OVERNIGHT BUT COVERAGE SHOULD REMAIN
SCATTERED. UPPER LEVEL LOW CURRENTLY OVER THE DESERT SOUTHWEST WILL
EJECT EASTWARD TOWARD THE CENTRAL PLAINS. THIS WILL KEEP SOUTHERLY
FLOW IN PLACE OVERNIGHT...AND EVENTUALLY THE REDEVELOPMENT OF
STRATUS CLOUDS OVER MUCH OF THE AREA. PATCHY FOG IS POSSIBLE OVER
CENTRAL NEB...BUT BUFKIT DATA CONTINUES TO SUPPORT THICK LOW STRATUS
IN OUR ZONES. THIS IS ALSO SUPPORTED BY VISBY FIELDS IN RECENT RUNS
OF THE HRRR AND NAM. CONFIDENCE NOT HIGH ENOUGH TO INCLUDE ANY FOG
IN THE GRIDS AT THIS POINT...BUT THE EVENING SHIFT WILL NEED TO
REEVALUATE.
MODELS PAINT QPF ACROSS MUCH OF THE CWA BY FRIDAY AFTERNOON...BUT
REMAIN ALL OVER THE PLACE IN REGARDS TO THEIR PLACEMENT. EXPECTING
SCATTERED AND DISORGANIZED SHOWERS AND THUNDERSTORMS DUE TO LACK OF
A FOCUS FOR DEVELOPMENT. NOT EXPECTING MUCH IN THE WAY OF SEVERE
WEATHER AS THE MUCH BETTER ENVIRONMENT WILL BE OFF TO OUR SOUTH AND
EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU APR 23 2015
LONG WAVE TROUGH WILL BE MOVING INLAND FROM THE WEST COAST
FRIDAY NIGHT...WITH A LEAD SHORTWAVE MOVING ACROSS THE CENTRAL PLAINS
AHEAD OF THE TROUGH FRIDAY NIGHT. OPERATIONAL MODELS FCST THE
CENTRAL PLAINS TROUGH TO BECOME CLOSED NEAR OR JUST WEST OF THE MID
MISSOURI VALLEY. THIS WILL BE A RATHER DISORGANIZED EVENT...AND
WITH ONLY WEAK MOISTURE TRANSPORT...LIFT WILL ALSO BE SOMEWHAT
LIMITED AND UNFOCUSED. THIS CONTINUES TO SUGGEST A SHOWERY AND
UNORGANIZED PRECIPITATION EVENT. WILL LIMIT HIGHEST POPS TO 40 TO
50 PERCENT EVENING AND 20 TO 30 PERCENT AFTER MIDNIGHT. BEST
INSTABILITY ACROSS SERN ZONES...WITH HIGHER TSTM CHANCES WITH ONLY
ISOLATED EXPECTED ACROSS THE NORTH/NORTHWEST.
THE MAIN UPPER TROUGH WILL DIG SOUTHEAST ACROSS THE GREAT BASIN ON
SATURDAY AS A TRANSITORY RIDGE MOVES INTO THE CNTRL PLAINS. THIS
WILL LESSEN POPS TO ONLY A SLIGHT CHANCE NORTH AND WEST WITH PARTLY
SUNNY SKIES AND HIGH TEMPS NEAR 60 NORTHEAST TO NEAR 70 FAR
SOUTHWEST. THE GFS ENSEMBLE...GFS...AND ECMWF ALL AGREE THAT THE
UPPER TROUGH WILL DEEPEN INTO THE FOUR CORNERS REGION SATURDAY
NIGHT WITH AN AMPLIFIED SRLY FLOW ALOFT ACROSS THE CNTRL HIGH
PLAINS. CHCS FOR SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE
HIGHS PLAINS WITH CHC POPS WEST OF HWY 83...AND NO WX ACROSS THE
EAST. ANY SHOWERS THAT DEVELOP WILL MOVE NORTH WILL LITTLE OR NOW
EASTWARD PROGRESSION. MEDIUM RANGE MODELS THEN INDICATED CLOSED
LOW WILL TRACK EAST ACROSS NEW MEXICO...THE TEXAS PANHANDLE...AND
THEN ACROSS NORTHERN TEXAS AND SOUTHERN OKLAHOMA SUNDAY THROUGH
MONDAY NIGHT. THERE REMAINS ENOUGH MODEL AGREEMENT AND CONFIDENCE
TO KEEP POPS INTO THE LIKELY CATEGORY ACROSS THE EASTERN PANHANDLE
SUNDAY WITH CHC POPS EAST TO VALENTINE THROUGH BROKEN BOW. AS NRN
STREAM TROUGH APPROACHES SUNDAY NIGHT AND MONDAY...POPS LESSEN AND
REMAIN ONLY ACROSS THE WEST. DRY MONDAY NIGHT AND BEYOND. UPPER
RIDGE OVER THE GREAT BASIN WILL SLOWLY BUILD EAST INTO THE CENTRAL
CONUS THROUGH THURSDAY. THE COOLEST DAY LOOK TO BE SUNDAY AS
EASTERLY UPSLOPE WINDS AND CLOUDINESS/SHOWERS LIMITS HIGHS TO
LOWER MID 50S WEST TO NEAR 60 EAST. HIGHS THEN WARM INTO THE 60S
MONDAY/TUESDAY...LOW 70S WEDNESDAY...THEN MID/UPPER 70S THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1242 PM CDT THU APR 23 2015
MORNING STRATUS DECK FROM SOUTHWEST INTO CENTRAL NEBRASKA IS
BEGINNING TO LIFT AND ERODE EARLY THIS AFTERNOON. EXPECTING VFR
CIGS AT ALL TERMINALS IN WESTERN AND NORTH CENTRAL NEBRASKA BY MID
AFTERNOON. NEXT AVIATION CONCERN IS THE CHANCE FOR TSRA LATER THIS
AFTERNOON AND EVENING. THE ACTIVITY WILL LIKELY BE SCATTERED IN
COVERAGE..AND DOES NOT WARRANT MENTION IN THE TAF AT THIS TIME.
TRENDS WILL MONITORED THROUGH THE AFTERNOON AND TSRA AMENDMENTS
MADE TO THE TAF IF NECESSARY.
STRATUS CLOUDS AND LOW CIGS WILL REDEVELOP OVERNIGHT. CONFIDENCE
IS HIGH IN THE OCCURRENCE OF MVFR OR LOWER CIGS ACROSS SOUTHWEST
NEBRASKA...INCLUDING KLBF. FURTHER NORTH...NEAR KVTN...MODEL
GUIDANCE HAS BEEN HIT OR MISS WITH THE POTENTIAL LOW CIGS FOR
TONIGHT INTO FRIDAY MORNING. INCLUDED BKN030 GROUP TO HIGHLIGHT
THE POTENTIAL FOR LOWER CIGS AT KVTN...HOWEVER FORECASTER
CONFIDENCE IS LOW AT THIS TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MARTIN
SHORT TERM...MARTIN
LONG TERM...ROBERG
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1255 PM CDT THU APR 23 2015
.UPDATE...
ISSUED AT 637 AM CDT THU APR 23 2015
THE 06Z NAM CAME IN STILL TRYING TO INITIATE TSTMS OVER SW NEB
THIS MORNING. THIS AS INCREASING LOW-LVL MOISTURE CREATES
ELEVATED INSTABILITY. THE 08Z HRRR DOESN`T HAVE IT AND THAT
BOLSTERS OUR CONFIDENCE IN KEEPING THE FCST DRY.
AFTER REVIEWING MORE DATA FOR THE 12Z TAFS...INSERTED A MENTION OF
FOG IN THE FCST LATE TONIGHT INTO FRI AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT THU APR 23 2015
ALOFT: SPLIT FLOW CONTS BUT THE FCST AREA WILL BE MORE AFFECTED
BY THE SRN STREAM OVER THE NEXT 24 HRS. TWO UPR LOWS WERE OVER SRN
CA AND W OF THE BAJA PENINSULA. THESE LOWS WILL FILL AND
CONSOLIDATE AND PROGRESS THRU THE SW USA...WITH A +TILT TROF
EXTENDING FROM CO-AZ BY 12Z/FRI. IN THE MEANTIME...THE W FLOW
ALOFT OVER THE CNTRL PLAINS WILL BECOME ANTICYCLONIC AND
EVENTUALLY TURN SW.
SURFACE: HIGH PRES HAS DRIFTED INTO THE MS VALLEY AND WILL REMAIN
E OF THE REGION THRU TONIGHT. THE PRIMARY POLAR FRONT WILL REMAIN
OVER THE SRN PLAINS BUT BEGIN LIFTING N AS A WARM FRONT TONIGHT
...IN RESPONSE TO FALLING PRES WITHIN THE STRENGTHENING LEE TROF
AND EVENTUAL CYCLOGENESIS.
TODAY: GRADUALLY BECOMING CLOUDY. SATELLITE SHOWS STRATUS FORMING
AND EXPANDING ON THE COOL SIDE OF THE FRONT OVER NRN TX/OK/KS...
WITHIN A PLUME OF MODESTLY RICH LOW-LVL MOISTURE. THIS PLUME AND
THE STRATUS WILL OVERTAKE THE FCST AREA FROM SW-NE AND KEEP TEMPS
FROM REACHING THEIR MAX POTENTIAL.
QPF: ALL MODEL GRID-SCALE AND/OR CONVECTIVE PRECIP SCHEMES ARE
OUTPUTTING LIGHT QPF TODAY. JUST DON`T SEE IT HAPPENING GIVEN THE
LACK OF FORCING AND OVERALL RIDGING/SUBSIDENCE ALOFT. FCST
SOUNDINGS DON`T HAVE THE LOOK OF SPRINKLES EITHER. SO THEY WERE
WITHDRAWN FROM THE FCST. BELIEVE THE 00Z WRF-NMM DEPICTION IS MOST
LIKELY TO VERIFY. TODAY IS QUIET AND DRY THEN SCT TSTMS WILL
DEVELOP TO THE W LATE AFTERNOON WITHIN THE LEE TROF AND THEY
SHOULD PROPAGATE E AND BE MAINTAINED AS THEY ACCESS THE LLJ/WAA
AND GREATER LOW-LVL MOISTURE. NEW TSTMS MAY ALSO DEVELOP WITHIN
THE LLJ. BEST CHANCE FOR RAIN PER SREF QPF PROBABILITIES WILL BE
OVER N-CNTRL KS UP INTO THE SUPERIOR-HEBRON AREA.
INSTABILITY FROM THE 03Z SREF WILL BE ENOUGH TO SUPPORT THUNDER
FOR THE ENTIRE FCST AREA...BUT MUCAPE WILL BE UNDER 750 J/KG OVER
S- CNTRL NEB AND NOT EVEN REACH 1000 J/KG OVER N-CNTRL KS.
EFFECTIVE SHEAR WILL BE AROUND 25 KTS. SO RISK FOR EVEN A STRONG
TSTM APPEARS LIMITED.
TONIGHT: CLOUDY. SCT SHWRS/TSTMS. NOT EVERY LOCATION WILL SEE
THEM. THERE IS PLENTY OF UNCERTAINTY ON COVERAGE OF SHWRS/TSTMS.
CURRENTLY HAVE HIGHEST PROBABILITIES SE OF THE TRI-CITIES.
NUDGED LOW TEMPS ROUGHLY 3F ABOVE THE PREVIOUS FCST DUE TO
EXPECTED CLOUD COVER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CDT THU APR 23 2015
THE MAIN FOCUS IS ON TSTMS FRIDAY AND FRIDAY NIGHT.
ON FRIDAY...THE PATTERN ALOFT WILL FEATURE SOUTHWEST FLOW ACROSS
THE CENTRAL PLAINS WITH A LEAD SHORTWAVE TROUGH LIFTING ACROSS OUR
REGION AHEAD OF A DEEPER SHORTWAVE NEAR THE FOUR CORNERS REGION.
PCPN IS EXPECTED TO BE ONGOING/LINGERING INTO THE DAY ON FRIDAY
WITH THE PASSING LEAD WAVE...WITH REDEVELOPMENT OF RAIN SHOWERS
AND THUNDERSTORMS EXPECTED FRIDAY AFTERNOON/EVENING AND CONTINUING
THRU FRIDAY NIGHT AS THE SOUTHERN DEEPER TROUGH LIFTS OUT ACROSS
THE CENTRAL PLAINS.
CANNOT RULE OUT THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY ACROSS KANSAS INTO THE SOUTHERN PORTION OF NEBRASKA
FRIDAY AFTN/EVE. THE FIRST PART OF THE DAY ON FRIDAY WILL LIKELY
SEE REMNANT/DEPARTING CONVECTION AND A FAIR AMOUNT OF CLOUD COVER.
BREAKS IN THE CLOUDS ARE EXPECTED ACROSS OUR SOUTHERN AND WESTERN
ZONES HEADING INTO THE AFTERNOON AND A MOISTURE AXIS WITH SFC DPS
IN THE MID 50S ARE FORECAST TO ALIGN ACROSS THE EASTERN HALF OF
KANSAS INTO SOUTHEAST NEB WITH INSTABILITY PROGGED TO INCREASE TO
AROUND 1500 J/KG OR SO BY EVENING ACROSS OUR SOUTHERN ZONES.
STORMS ARE EXPECTED TO INITIATE ALONG/AHEAD OF THE SFC TROUGH AND
DRY LINE AND WARM FRONTAL BOUNDARY. SHEAR PROGS AVERAGE 30KTS AND
COMBINED WITH THE INSTABILITY...THE PRIMARY HAZARDS FROM THE
STORMS WILL BE LARGE HAIL/DAMAGING WINDS THRU THE EVENING
HOURS...WITH CHCS FOR SEVERE STORMS DECREASING OVERNIGHT.
ON SATURDAY...A FEW SHOWERS MAY LINGER IN THE MORNING UNTIL THE
UPPER LOW PASSES FARTHER TO THE EAST...THEN THE FORECAST DRIES OUT
FOR THE REMAINDER OF THE DAY. HEIGHTS RISE BEHIND THE DEPARTING
SYSTEM IN SHORTWAVE RIDGING IN BETWEEN ANOTHER TROUGH MOVING INTO
THE CENTRAL ROCKIES.
THERE REMAINS A FAIR AMOUNT OF UNCERTAINTY IN HANDLING THE UPPER
LOW IN THE ROCKIES OVER THE WEEKEND WITH THE GFS LIFTING OUT THE
SYSTEM FARTHER NORTH THAN THE ECMWF AND GFS ENSEMBLE. HAVE
MAINTAINED SOME BUFFER LOW POPS FOR OUR WESTERN COUNTIES SATURDAY
NIGHT BUT IN GENERAL HAVE LOWERED POPS FROM SUNDAY THROUGH TUESDAY
WITH MODELS BEGINNING TO FAVOR A MORE SOUTHERN SOLUTION.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1245 PM CDT THU APR 23 2015
SIGNIFICANT WEATHER CHANGES WILL IMPACT AVIATION SERVICES FOR THE
AREA...ESPECIALLY TONIGHT AND SATURDAY. ALREADY SEEING SOME
INCREASE IN LOW/MID LEVEL CLOUDS ACROSS THE AREA...BUT MODELS ARE
IN GOOD AGREEMENT DEEPER MOISTURE TONIGHT WILL RESULT IN AT LEAST
MVFR CEILINGS...IF NOT IFR CEILINGS FOR THE FORECAST AREA TONIGHT
AND MOST OF THE DAY SATURDAY. ALL THE WHILE...A DEVELOPING UPPER
WAVE WILL MOVE ACROSS THE AREA AND CHURN UP SOME SHOWERS...AND
ISOLATED THUNDERSTORMS LATE TONIGHT WHICH WILL LIKELY LINGER INTO
THE DAY FRIDAY. SHOULD RESULT IN A PERIOD OF AT LEAST STEADY
PRECIPITATION DURING THE LAST 6 TO 9 HOURS OF THE FORECAST PERIOD.
VISIBILITIES COULD BE UP AND DOWN DURING THAT TIME...AND CURRENT
VSBY FORECAST OF 2-3 MILES IS LIKELY TOO HIGH BUT THERE COULD BE
SIGNIFICANT VISIBILITY VARIATIONS AT TIMES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...FAY
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
637 AM CDT THU APR 23 2015
.UPDATE...
ISSUED AT 637 AM CDT THU APR 23 2015
THE 06Z NAM CAME IN STILL TRYING TO INITIATE TSTMS OVER SW NEB
THIS MORNING. THIS AS INCREASING LOW-LVL MOISTURE CREATES
ELEVATED INSTABILITY. THE 08Z HRRR DOESN`T HAVE IT AND THAT
BOLSTERS OUR CONFIDENCE IN KEEPING THE FCST DRY.
AFTER REVIEWING MORE DATA FOR THE 12Z TAFS...INSERTED A MENTION OF
FOG IN THE FCST LATE TONIGHT INTO FRI AM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT THU APR 23 2015
ALOFT: SPLIT FLOW CONTS BUT THE FCST AREA WILL BE MORE AFFECTED
BY THE SRN STREAM OVER THE NEXT 24 HRS. TWO UPR LOWS WERE OVER SRN
CA AND W OF THE BAJA PENINSULA. THESE LOWS WILL FILL AND
CONSOLIDATE AND PROGRESS THRU THE SW USA...WITH A +TILT TROF
EXTENDING FROM CO-AZ BY 12Z/FRI. IN THE MEANTIME...THE W FLOW
ALOFT OVER THE CNTRL PLAINS WILL BECOME ANTICYCLONIC AND
EVENTUALLY TURN SW.
SURFACE: HIGH PRES HAS DRIFTED INTO THE MS VALLEY AND WILL REMAIN
E OF THE REGION THRU TONIGHT. THE PRIMARY POLAR FRONT WILL REMAIN
OVER THE SRN PLAINS BUT BEGIN LIFTING N AS A WARM FRONT TONIGHT
...IN RESPONSE TO FALLING PRES WITHIN THE STRENGTHENING LEE TROF
AND EVENTUAL CYCLOGENESIS.
TODAY: GRADUALLY BECOMING CLOUDY. SATELLITE SHOWS STRATUS FORMING
AND EXPANDING ON THE COOL SIDE OF THE FRONT OVER NRN TX/OK/KS...
WITHIN A PLUME OF MODESTLY RICH LOW-LVL MOISTURE. THIS PLUME AND
THE STRATUS WILL OVERTAKE THE FCST AREA FROM SW-NE AND KEEP TEMPS
FROM REACHING THEIR MAX POTENTIAL.
QPF: ALL MODEL GRID-SCALE AND/OR CONVECTIVE PRECIP SCHEMES ARE
OUTPUTTING LIGHT QPF TODAY. JUST DON`T SEE IT HAPPENING GIVEN THE
LACK OF FORCING AND OVERALL RIDGING/SUBSIDENCE ALOFT. FCST
SOUNDINGS DON`T HAVE THE LOOK OF SPRINKLES EITHER. SO THEY WERE
WITHDRAWN FROM THE FCST. BELIEVE THE 00Z WRF-NMM DEPICTION IS MOST
LIKELY TO VERIFY. TODAY IS QUIET AND DRY THEN SCT TSTMS WILL
DEVELOP TO THE W LATE AFTERNOON WITHIN THE LEE TROF AND THEY
SHOULD PROPAGATE E AND BE MAINTAINED AS THEY ACCESS THE LLJ/WAA
AND GREATER LOW-LVL MOISTURE. NEW TSTMS MAY ALSO DEVELOP WITHIN
THE LLJ. BEST CHANCE FOR RAIN PER SREF QPF PROBABILITIES WILL BE
OVER N-CNTRL KS UP INTO THE SUPERIOR-HEBRON AREA.
INSTABILITY FROM THE 03Z SREF WILL BE ENOUGH TO SUPPORT THUNDER
FOR THE ENTIRE FCST AREA...BUT MUCAPE WILL BE UNDER 750 J/KG OVER
S- CNTRL NEB AND NOT EVEN REACH 1000 J/KG OVER N-CNTRL KS.
EFFECTIVE SHEAR WILL BE AROUND 25 KTS. SO RISK FOR EVEN A STRONG
TSTM APPEARS LIMITED.
TONIGHT: CLOUDY. SCT SHWRS/TSTMS. NOT EVERY LOCATION WILL SEE
THEM. THERE IS PLENTY OF UNCERTAINTY ON COVERAGE OF SHWRS/TSTMS.
CURRENTLY HAVE HIGHEST PROBABILITIES SE OF THE TRI-CITIES.
NUDGED LOW TEMPS ROUGHLY 3F ABOVE THE PREVIOUS FCST DUE TO
EXPECTED CLOUD COVER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CDT THU APR 23 2015
THE MAIN FOCUS IS ON TSTMS FRIDAY AND FRIDAY NIGHT.
ON FRIDAY...THE PATTERN ALOFT WILL FEATURE SOUTHWEST FLOW ACROSS
THE CENTRAL PLAINS WITH A LEAD SHORTWAVE TROUGH LIFTING ACROSS OUR
REGION AHEAD OF A DEEPER SHORTWAVE NEAR THE FOUR CORNERS REGION.
PCPN IS EXPECTED TO BE ONGOING/LINGERING INTO THE DAY ON FRIDAY
WITH THE PASSING LEAD WAVE...WITH REDEVELOPMENT OF RAIN SHOWERS
AND THUNDERSTORMS EXPECTED FRIDAY AFTERNOON/EVENING AND CONTINUING
THRU FRIDAY NIGHT AS THE SOUTHERN DEEPER TROUGH LIFTS OUT ACROSS
THE CENTRAL PLAINS.
CANNOT RULE OUT THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY ACROSS KANSAS INTO THE SOUTHERN PORTION OF NEBRASKA
FRIDAY AFTN/EVE. THE FIRST PART OF THE DAY ON FRIDAY WILL LIKELY
SEE REMNANT/DEPARTING CONVECTION AND A FAIR AMOUNT OF CLOUD COVER.
BREAKS IN THE CLOUDS ARE EXPECTED ACROSS OUR SOUTHERN AND WESTERN
ZONES HEADING INTO THE AFTERNOON AND A MOISTURE AXIS WITH SFC DPS
IN THE MID 50S ARE FORECAST TO ALIGN ACROSS THE EASTERN HALF OF
KANSAS INTO SOUTHEAST NEB WITH INSTABILITY PROGGED TO INCREASE TO
AROUND 1500 J/KG OR SO BY EVENING ACROSS OUR SOUTHERN ZONES.
STORMS ARE EXPECTED TO INITIATE ALONG/AHEAD OF THE SFC TROUGH AND
DRY LINE AND WARM FRONTAL BOUNDARY. SHEAR PROGS AVERAGE 30KTS AND
COMBINED WITH THE INSTABILITY...THE PRIMARY HAZARDS FROM THE
STORMS WILL BE LARGE HAIL/DAMAGING WINDS THRU THE EVENING
HOURS...WITH CHCS FOR SEVERE STORMS DECREASING OVERNIGHT.
ON SATURDAY...A FEW SHOWERS MAY LINGER IN THE MORNING UNTIL THE
UPPER LOW PASSES FARTHER TO THE EAST...THEN THE FORECAST DRIES OUT
FOR THE REMAINDER OF THE DAY. HEIGHTS RISE BEHIND THE DEPARTING
SYSTEM IN SHORTWAVE RIDGING IN BETWEEN ANOTHER TROUGH MOVING INTO
THE CENTRAL ROCKIES.
THERE REMAINS A FAIR AMOUNT OF UNCERTAINTY IN HANDLING THE UPPER
LOW IN THE ROCKIES OVER THE WEEKEND WITH THE GFS LIFTING OUT THE
SYSTEM FARTHER NORTH THAN THE ECMWF AND GFS ENSEMBLE. HAVE
MAINTAINED SOME BUFFER LOW POPS FOR OUR WESTERN COUNTIES SATURDAY
NIGHT BUT IN GENERAL HAVE LOWERED POPS FROM SUNDAY THROUGH TUESDAY
WITH MODELS BEGINNING TO FAVOR A MORE SOUTHERN SOLUTION.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRI MORNING)
ISSUED AT 637 AM CDT THU APR 23 2015
TODAY: VFR TO START BUT STRATUS IS EXPANDING ACROSS KS AND WILL BE
LIFTING INTO THE TERMINALS. CURRENT TIMING OF ARRIVAL IS 17Z-18Z.
SE WINDS WILL INCREASE AND GUST UP TO 25 KTS. CONFIDENCE: MEDIUM
DUE TO UNCERTAINTY ON TIMING STRATUS AND HEIGHT OF CIGS.
TONIGHT: CIGS DEGRADE TO MVFR AND IFR. ALL FCST GUIDANCE IS IN
UNISON THAT CIGS LOWER TO 300-500 FT WITH MVFR VSBYS. SCT SHWRS/
TSTMS AFTER 06Z. SE WINDS WILL REMAIN GUSTY. CONFIDENCE: MEDIUM TO
DUE UNCERTAINTY ON TIMING OF CIG HEIGHT CHANGES AND MAGNITUDE OF
VSBYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...FAY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
845 PM PDT FRI APR 24 2015
.SYNOPSIS...UNSETTLED WEATHER WILL CONTINUE THROUGH SATURDAY NIGHT
WITH AREAS OF SHOWERS AND THUNDERSTORMS ALONG WITH GUSTY WINDS AND
COOLER TEMPERATURES. GREATEST CHANCES FOR RAINFALL ARE EXPECTED
ACROSS THE SOUTHERN GREAT BASIN AND NORTHWEST ARIZONA. IN
ADDITION...STRONG WINDS WILL DEVELOP ACROSS THE WESTERN MOJAVE
DESERT FRIDAY AND BECOME QUITE STRONG ON SATURDAY RESULTING IN AREAS
OF BLOWING DUST. WARMER AND DRIER CONDITIONS ARE EXPECTED NEXT WEEK.
&&
.UPDATE...MAIN SHORT TERM CONCERN IS WINDS ACROSS THE WESTERN MOJAVE
DESERT AND THE SOUTHWARD DEVELOPMENT OF PRECIP ACROSS LINCOLN COUNTY
AND NORTHERN CLARK COUNTY. WINDS THIS EVENING HAVE COME DOWN
SOMEWHAT NEAR DAGGETT AND BICYCLE LAKE WHERE GUSTS IN THE PAST HOUR
HAVE BEEN BELOW 40 MPH FOR BOTH LOCATIONS WITH IMPROVING
VISIBILITIES. I EXPECT THIS LULL TO CONTINUE MOST OF THE NIGHT BUT
IT WILL REMAIN GUSTY BEFORE REALLY PICKING UP AGAIN BY MID MORNING
SATURDAY. THE HIGH WIND WARNING FOR THIS AREA LOOKS GOOD.
FURTHER WEST...NICE ARCING CLOUD BAND EXTENDS FROM LINCOLN COUNTY
ALL THE WAY DOWN TO THE WESTERN MOJAVE DESERT WITH OGRANIZED SHOWER
ACTIVITY EVIDENT ON RADAR FROM SOUTHERN LINCOLN COUNTY INTO NORTHERN
CLARK COUNTY. I DO BELIEVE THIS WILL REMAIN NORTH OF THE LAS VEGAS
VALLEY AND LATEST HRRR GUIDANCE SUPPORTS THIS BUT YOU WONT HAVE TO
GO FAR TO OBSERVE SHOWER ACTIVITY WITH REASONABLY HIGH PROBABILITIES
FOR SHOWERS FROM MOAPA AND MESQUITE NORTHWARDS INTO LINCOLN COUNTY.
IVE MADE SOME ADJUSTMENTS TO THE POP FORECAST MAINLY TO ACCOUNT FOR
CURRENT AND ANTICIPATED RAINFALL TRENDS AND ADJUSTED THE CLOUD
COVER. OTHERWISE THE FORECAST IS IN GOOD SHAPE.
-OUTLER-
.SHORT TERM...THROUGH SATURDAY NIGHT.
SHOWER AND THUNDERSTORM ACTIVITY HAS BEEN FAIRLY ISOLATED THIS
AFTERNOON WITH MOST ACTIVITY OCCURRING OVER PORTIONS OF LINCOLN AND
EASTERN CLARK COUNTIES. DRIER AND A BIT MORE STABLE AIR WAS WORKING
IN FROM THE WEST BEHIND A WEAK SHORTWAVE THAT IS CURRENTLY PUSHING
THROUGH THE FAR EASTERN AREAS OF THE GREAT BASIN. ALONG WITH THIS
DRIER AIR ARE STRONG WINDS THAT HAVE BEEN BLOWING ACROSS PORTIONS OF
THE WESTERN MOJAVE DESERT. THERE HAVE BEEN A FEW PLACES THAT HAVE
GUSTED OVER 50 MPH WITH BICYCLE LAKE JUST REACHING 58 MPH WITHIN THE
PAST HOUR. THESE STRONG WINDS WILL CONTINUE INTO THIS EVENING...BUT
ARE EXPECTED TO LULL A BIT OVERNIGHT BEFORE INCREASING ONCE AGAIN
SATURDAY. CURRENTLY WE HAVE WIND ADVISORIES IN PLACE FOR THE WESTERN
MOJAVE DESERT THROUGH SATURDAY...BUT THAT ADVISORY MAY NEED TO BE
UPGRADED TO A WARNING OVERNIGHT AS WINDS MAY GUST AS HIGH AS 60 MPH
SATURDAY.
WITH THE NEXT TROUGH MOVING INTO THE REGION PRECIPITATION
IS EXPECTED TO INCREASE LATE SATURDAY MORNING OVER THE FAR NORTHERN
AREAS OF THE CWA AHEAD OF A FAIRLY STRONG COLD FRONT THAT WILL MOVE
THROUGH THE AREA. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
AHEAD AND JUST BEHIND THE FRONT WITH THE MOST WIDESPREAD AREAS OF
PRECIPITATION OCCURRING OVER ESMERALDA...CENTRAL NYE AND LINCOLN
COUNTIES SATURDAY AFTERNOON. AS THE FRONT TRACKS SOUTH SATURDAY
EVENING...PRECIPITATION IS EXPECTED TO INCREASE OVER CLARK AND
MOHAVE COUNTIES WITH MOSTLY ISOLATED TO SCATTERED SHOWERS OVER
MOHAVE CLARK COUNTY WITH MORE WIDESPREAD PRECIPITATION OVER MOHAVE
COUNTY. WINDS AHEAD OF THE FRONT ARE EXPECTED TO INCREASE ACROSS
EASTERN SAN BERNARDINO...SOUTHERN CLARK AND MOHAVE COUNTIES SATURDAY
AFTERNOON AND HAVE GONE AHEAD AND ISSUED A WIND ADVISORY FOR THOSE
AREAS INTO SATURDAY EVENING. THE FRONT IS EXPECTED TO EXIT FAIRLY
QUICKLY LATE SATURDAY NIGHT WITH MOST OF THE PRECIPITATION ENDING BY
SUNDAY MORNING LEAVING GUSTY NORTH WINDS ACROSS THE REGION.
OUTSIDE OF A FEW LIGHT SHOWERS OVER THE FAR EASTERN AREAS OF THE CWA
SUNDAY...CONDITIONS ARE EXPECTED TO REMAIN DRY. THE STRONGEST WINDS
WILL OCCUR DOWN THE COLORADO RIVER AND ADVISORIES WILL BE POSSIBLE.
COOLER TEMPERATURES EXPECTED SATURDAY WITH READINGS DOWN ABOUT 5-7
DEGREES WITH A SLIGHT WARMING TREND SUNDAY.
.LONG TERM...MONDAY MORNING THROUGH FRIDAY.
A RIDGE OF HIGH PRESSURE WILL BEGIN TO BUILD INTO THE AREA ON
MONDAY...BUT NORTHERLY WINDS...PARTICULARLY DOWN THE COLORADO RIVER
VALLEY WILL PERSIST FOR ONE MORE DAY...ALTHOUGH THE WINDS WILL BE
LIGHTER THAN ON SUNDAY. TEMPERATURES WILL RECOVER TO AROUND THE
SEASONAL NORMS ON MONDAY AFTERNOON...WHICH IS THE LOW 80S IN LAS
VEGAS. THE AREA OF HIGH PRESSURE WILL BE CENTERED OVER THE AREA ON
TUESDAY AND WILL SHIFT SLOWLY TO THE EAST DURING THE DAY ON
WEDNESDAY. HIGH TEMPERATURES WILL CONTINUE TO TREND UPWARD BOTH
DAYS...CLIMBING ON AVERAGE 10 DEGREES BETWEEN MONDAY AND WEDNESDAY.
THERE IS SOME DIFFERENCE IN THE STRENGTH AND EXACT TIMING...BUT THE
GFS...GEFS AND ECMWF HAVE A TROUGH OF LOW PRESSURE IN THE VICINITY
OF THE NORTHERN CALIFORNIA COAST ON THURSDAY AND FRIDAY. THIS WILL
PROVIDE SOME INCREASE IN WINDS...PARTICULARLY NORTH OF LAS VEGAS BY
THURSDAY AFTERNOON. AT THIS POINT...THE MAIN WEATHER ISSUE WITH THE
TROUGH LOOKS TO BE WINDS WITH MOISTURE BEING LIMITED AND WELL NORTH
OF OUR AREA.
&&
.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS BETWEEN 15-25
KTS WITH OCCASIONAL GUSTS TO 30 KTS EXPECTED INTO THIS EVENING...BUT
WILL GRADUALLY DIMINISH AFTER 06Z TO AROUND 10-15 KTS. WINDS ARE
EXPECTED TO INCREASE ONCE AGAIN LATE SATURDAY MORNING WITH WINDS
BETWEEN 20-30 KTS AND GUSTS UP TO 35 KTS AT TIMES. SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON WITH
MOST REMAINING OVER THE MOUNTAINS...HOWEVER ITS POSSIBLE THAT THEY
MAY DEVELOP IN THE VALLEY BETWEEN 22Z-04Z. CIGS ARE EXPECTED TO
REMAIN ABOVE 8K FEET BUT MAY LOWER TO AROUND 6K FEET NEAR ANY
SHOWERS.
.FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...STRONG WEST WINDS WILL OCCUR OVER WESTERN SAN
BERNARDINO COUNTY WHERE GUST TO 55 MPH ARE POSSIBLE INTO THIS
EVENING. ELSEWHERE SOUTHWEST WINDS GUSTING TO 30 MPH WILL GRADUALLY
DIMINISH THIS EVENING WITH MOST LOCATIONS SEEING WINDS LESS THAN 15
KTS. ISOLATED SHOWERS AND THUNDERSTORMS WILL OCCUR THIS EVENING OVER
MAINLY LINCOLN AND MOHAVE COUNTIES. GUSTY SOUTHWEST TO WEST WINDS
WILL OCCUR OVER SOUTHERN PORTIONS OF THE AREA. PRECIPITATION IS
EXPECTED TO INCREASE OVER ESMERALDA...CENTRAL NYE AND LINCOLN
COUNTIES WITH WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED LATE
SATURDAY AFTERNOON AND EVENING. SCATTERED SHOWERS AND THUNDERSTORMS
EXPECTED ELSEWHERE. CIGS MAY LOWER TO AROUND 5-6K FEET AT TIMES NEAR
ANY RAINFALL.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT ACCORDING TO
STANDARD OPERATING PROCEDURES.
&&
$$
SHORT TERM/AVIATION...GORELOW
LONG TERM...CZYZYK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS ELKO NV
801 PM PDT FRI APR 24 2015
.SYNOPSIS...VALLEY RAIN AND MOUNTAIN SNOW TONIGHT AND AGAIN ON
SATURDAY. ALSO ON SATURDAY...WINDS WILL BECOME GUSTY AND MOST
AREAS WILL HAVE A SLIGHT CHANCE OF THUNDERSTORMS. SATURDAY EVENING
SNOW LEVELS WILL LOWER TO VALLEY FLOORS AS PRECIPITATION BEGINS TO
TAPER OFF. COOL AND DRY ON SUNDAY WITH A WARMING TREND NEXT WEEK.
&&
.UPDATE...LOWERED SNOW LEVELS FOR TONIGHT BASED ON REPORTS OF SNOW
REACHING THE GROUND IN WELLS. NO OTHER CHANGES AT THIS TMIE.
PRECIPITATION WILL BE SPOTTY FROM THIS POINT ON AND LITTLE IF ANY
VALLEY ACCUMULATION IS EXPECTED SO NO HEADLINES ARE NECESSARY. RCM
&&
.PREV DISCUSSION... /ISSUED AT 326 PM /
SYNOPSIS...VALLEY RAIN AND MOUNTAIN SNOW TODAY AND AGAIN ON
SATURDAY. ALSO ON SATURDAY...WINDS WILL BECOME GUSTY AND MOST
AREAS WILL HAVE A SLIGHT CHANCE OF THUNDERSTORMS. SATURDAY EVENING
SNOW LEVELS WILL LOWER TO VALLEY FLOORS AS PRECIPITATION BEGINS TO
TAPER OFF. COOL AND DRY ON SUNDAY WITH A WARMING TREND NEXT WEEK.
SHORT TERM...TONIGHT THROUGH MONDAY. CURRENTLY...A SHORTWAVE IS
MOVING THROUGH NORTHERN NEVADA. THIS SHOWS UP NICELY ON THE WATER
VAPOR. THIS WILL CONTINUE TO SLIDE EASTWARD THROUGH THE
EVENING...DEVELOPING/MAINTAINING LIGHT TO MODERATE RAIN SHOWERS
AND AN ISOLATED THUNDERSTORM OR TWO. ANY ONE SHOWER COULD DROP
~0.25 INCHES OF RAIN. THE HRRR SHOWS CONVECTION ENDING AROUND 00Z
TO 03Z FROM WEST TO EAST.
WE WILL HAVE A BRIEF BREAK FROM SHOWERS LATER THIS EVENING...BUT
THAT WILL BE SHORT LIVED AS THE NEXT WAVE DROPS IN FROM THE
NORTHWEST. THIS TROUGH IS MUCH STRONGER AND IS NEGATIVELY TILTED.
DUE TO THE NEGATIVE TILT OF THE TROUGH...THE MODELS MAY BE A TAD
TOO QUICK WITH THE TROUGH. THEREFORE...THE HIGHEST QPF/SNOW
AMOUNTS ARE IN WHITE PINE AND NE NYE COUNTIES. ISOLATED TS WILL
AGAIN BE POSSIBLE ON SATURDAY...MAINLY EAST OF HIGHWAY 95. SNOW
LEVELS WILL START OUT ABOVE 7000FT...BUT WILL LOWER TO MOST
VALLEY FLOORS BETWEEN 5500-6500FT THROUGH THE AFTERNOON/EVENING.
SNOW LEVELS IN FAR NW NV WILL START OUT AROUND 6500FT AND LOWER
TO 5000FT BY SATURDAY EVENING. EXPECTING LITTLE...IF ANY...IMPACTS
IN THE VALLEYS. THE COLD AIR WILL BE SLOW TO ARRIVE...AND GIVEN
THE HIGH SUN ANGLE...ROADS SHOULD REMAIN WET. ANY IMPACTS WILL BE
ABOVE 6500FT...BUT WILL STILL BE MINIMAL GIVEN THE TIME OF YEAR. A
TRACE TO ONE INCH OF SNOW WILL BE POSSIBLE BELOW 6500FT...WITH
SEVERAL INCHES IN THE MOUNTAINS. SOME OF THE HIGHER ELEVATION
VALLEYS IN NORTHERN ELKO AND WHITE PINE COUNTIES COULD LOCALLY SEE
UP TO 3 INCHES. LOCALLY A FOOT OF SNOW COULD FALL IN THE HIGHEST
MTNS IN WHITE PINE AND NE NYE COUNTIES.
IN ADDITION...GUSTY NW WINDS WILL DEVELOP SATURDAY EVENING THROUGH
SUNDAY AFTERNOON. NW NYE WILL APPROACH WIND ADV CRITERIA DUE TO
PRESSURE GRADIENT/PRESSURE FALLS. MAV/MET GUIDANCE SUPPORTS STRONG
GUSTS AND THIS WILL BE MONITORED FOR AN ADV.
BY SUNDAY MORNING...MOST LOCATIONS WILL BE DRY. A WARMING TREND
WILL COMMENCE ON MONDAY...WHERE 60S/70S WILL BE PREVALENT.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY. MODELS IN FAIRLY GOOD
AGREEMENT WITH THE OVERALL PATTERN THROUGH WEDNESDAY NIGHT. RIDGE
BUILDING IN FROM THE WEST MONDAY NIGHT WITH RIDGE AXIS OVER THE CWA
BY 18Z TUESDAY FOR A WARMING TREND AND DRY CONDITIONS. SHORTWAVE
PASSING TO THE NORTHWEST FLATTENS THE RIDGE A BIT BUT KEEPS WARM
SOUTHWEST FLOW OVER OUR REGION...WITH TEMPERATURES NEAR 80 DEGREES
BY WEDNESDAY. 12Z MODELS DIFFER WITH GFS NOW TRYING TO DIG A STRONG
TROF INTO NORTHERN CA WHILE THE EC MUCH WEAKER WITH THIS SHORTWAVE.
STILL...EITHER SOLUTION WOULD KEEP THE CWA DRY...BUT GFS WOULD IMPLY
WINDY CONDITIONS AND SOME INSTABILITY IN CENTRAL NV. UNTIL MODELS
COME INTO BETTER AGREEMENT...RIGHT NOW WILL LEAN TOWARD WEAKER EC
MODEL IN KEEPING THE CWA DRY WITH LESS WIND AND STABILITY.
AVIATION...RAIN SHOWERS OVER THE CWA WILL DECREASE THIS EVENING
BRIEFLY BEFORE INCREASING AGAIN AFTER 10Z AT KWMC...18Z AT KEKO
..AND 20Z AT KELY. THUS ON SATURDAY...CIGS ARE EXPECTED TO LOWER TO
AT LEAST MVFR AND PERHAPS BRIEFLY IFR AT THESE TERMINALS. WINDS WILL
BE GUSTY AT THE TERMINALS THROUGH 03Z THIS EVENING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/99
AREA FORECAST DISCUSSION
NWS BISMARCK ND
505 PM CDT THU APR 23 2015
.UPDATE...
ISSUED AT 503 PM CDT THU APR 23 2015
GETTING REPORTS OF SNOW FROM STANLEY AND PARSHALL AREAS. LOOKS
LIKE COOLING TO THE WET BULB IS CREATING ENOUGH COOLING FOR SNOW
LATE THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
SHOWERS THIS AFTERNOON THROUGH TONIGHT HIGHLIGHT THE SHORT TERM
FORECAST.
OUTSIDE OF THE HIGHWAY 200 CORRIDOR...THE MAJORITY OF
PRECIPITATION IS NOT REACHING THE GROUND DUE TO DRY AIR IN THE
SUB-800 MB LAYER. THE 16-18 UTC HRRR ITERATIONS HAVE THE BEST
HANDLING OF THE ONGOING PRECIPITATION...ESPECIALLY THAT WHICH IS
REACHING THE GROUND...AND WILL WEIGH HEAVILY ON THEIR SOLUTIONS
THROUGH AFTERNOON AND EVENING. THEREAFTER...THE 12 AND INCOMING 18
UTC GLOBAL AND HIGH RESOLUTION SUITES ARE IN AGREEMENT ON ELEVATED
SHOWERS DEVELOPING TONIGHT ACROSS THE JAMES AND INTO THE RED RIVER
VALLEYS BY 05 UTC WITH A MODEST LOW LEVEL JET AHEAD OF THE
SURFACE LOW ACROSS WESTERN SOUTH DAKOTA. GIVEN MARGINALLY POSITIVE
SHOWALTER VALUES...WILL NOT PUT IN THUNDER AT THIS TIME. FRIDAY
APPEARS TO BE DRY ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN
THE STRONGER LOW ACROSS THE CENTRAL PLAINS AND THE PACIFIC
NORTHWEST TROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
A SPLIT FLOW THROUGH THE WEEKEND WITH PERIODS OF INTERACTION
BETWEEN THE SOUTHERN STREAM AND NORTHERN STREAM. THIS WILL
ULTIMATELY SET UP AN INCREASINGLY WET/UNSETTLED WEATHER PATTERN
THROUGH EARLY NEXT WEEK. TWO MAIN SHORTWAVES TO PUSH ACROSS WESTERN
AND CENTRAL NORTH DAKOTA FRIDAY NIGHT THROUGH MONDAY. THE LATEST
ECMWF IS ADVERTISING A MORE CONTINUOUS RAIN OVER THE WEEKEND INTO
MONDAY...WHILE THE GFS/CANADIAN GEM HAS A MORE DISTINCT START/END
TIME WITH EACH WAVE. UTILIZED A BLEND OF THE ABOVE MODELS ABOVE.
EXPECT A BRIEF DRYING AND WARMING TREND BY MIDWEEK...THEN A
PROGRESSIVE AND POSSIBLY UNSETTLED WEATHER PATTERN SETTING UP LATE
IN THE EXTENDED.
FOR FRIDAY NIGHT THROUGH SATURDAY...A TRANSITORY 700MB-500MB RIDGE
DEVELOPS OUT AHEAD OF AN APPROACHING SHORTWAVE TROUGH SLIDING INTO
THE NORTHERN ROCKIES. THIS SHOULD KEEP CONDITIONS DRY FOR MOST AREAS
FRIDAY NIGHT BEFORE EAST TO SOUTHEAST WINDS ADVECT AN AREA OF
MOISTURE INTO THE WEST. THIS MOISTURE WILL CONVERGE INTO AN
APPROACHING SURFACE COLD FRONT IN EASTERN MONTANA. THUS POPS BECOME
LIKELY THEN CATEGORICAL SATURDAY IN THE WEST...WITH DRIER CONDITIONS
IN THE EAST AS MID LEVEL RIDGING REMAINS INTACT UNTIL 00Z SUNDAY.
SATURDAY NIGHT THROUGH MONDAY NIGHT...AS MENTIONED ABOVE THERE ARE
DIFFERENCES IN THE ECMWF AND GFS/GEM...ESPECIALLY SATURDAY NIGHT
THROUGH SUNDAY. PER GFS/GEM...THE SURFACE LOW/COLD FRONT AND SHORTWAVE
MOVE INTO SOUTHERN CANADA WITH SHOWERS DIMINISHING SATURDAY NIGHT
INTO SUNDAY. THE TRAILING COLD FRONT STALLS UNDER A SOUTHWEST FLOW
ALOFT...WITH LOW LEVEL SOUTH TO SOUTHEAST WINDS FEEDING MOISTURE
INTO NORTH DAKOTA. THE GFS/GEM MODELS TREND TOWARD A CESSATION TO
THE PRECIPITATION UNTIL SUNDAY NIGHT WHEN THE THE FRONT BECOMES
RE-ENERGIZED AS THE NEXT SHORTWAVE TROUGH APPROACHES. WITH THE
SURFACE COLD FRONT AND SOUTHERN STREAM MOISTURE ALREADY IN
PLACE...THIS SETS THE STAGE FOR A MORE WIDESPREAD PRECIPITATION
EVENT SUNDAY NIGHT THROUGH MONDAY. AS MENTIONED ABOVE THE LATEST
ECMWF REALLY DOES NOT STOP THE PRECIPITATION WITH THE INITIAL
SHORTWAVE...RATHER KEEPS THE SURGE MAINLY CONTINUOUS IN THE WEST AND
SLOWLY SPREADS IT EAST AND NORTH THROUGH MONDAY. TOTAL PRECIPITATION
AMOUNTS COULD RANGE BETWEEN A HALF INCH TO ONE INCH IN THE WEST TO
AROUND A QUARTER OF AN INCH IN CENTRAL NORTH DAKOTA THROUGH MONDAY NIGHT.
MONDAY NIGHT THROUGH THURSDAY...GOOD AGREEMENT THAT PRECIPITATION
WILL BE EAST OF THE JAMES RIVER VALLEY BY 12Z TUESDAY FOLLOWED BY
UPPER RIDGING TUESDAY AND WEDNESDAY. WARM AIR ADVECTION RAMPS UP
LATE TUESDAY INTO WEDNESDAY...AHEAD OF AN ADVANCING COLD FRONT WHICH
IS FORECAST TO CROSS SOUTHERN CANADA WEDNESDAY AFTERNOON/EVENING. THE GFS
SHOWS SOME LIGHT PRECIPITATION DEVELOPING IN THE NORTH BEHIND THE
FRONT WEDNESDAY AFTERNOON. THE ECMWF IS ABOUT 6HRS SLOWER WITH THE
COLD FRONT...NOT ARRIVING INTO THE NORTHWEST UNTIL AROUND 00Z
THURSDAY. THURSDAY LOOKS DRY...ALTHOUGH THIS MAY BE BRIEF AS
THE NEXT SYSTEM IS ALREADY APPROACHING THURSDAY NIGHT INTO FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT |247 PM CDT THU APR 23 2015
SCATTERED RAIN SHOWERS ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THIS AFTERNOON WILL CONTINUE TO MOVE EAST AND FADE WITH
SUNSET...BEFORE ADDITIONAL SHOWERS FORM TONIGHT NEAR KJMS AFTER 05
UTC. MVFR CONDITIONS IN RAIN POSSIBLE. OTHERWISE...VFR CONDITIONS
FOR THE 18 UTC CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
322 PM CDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 321 PM CDT THU APR 23 2015
PRECIP CHANCES AND TYPE TONIGHT AND TOMORROW WILL BE THE MAIN
FORECAST ISSUE FOR THE SHORT TERM.
WEST TO SOUTHWEST FLOW CONTINUES OVER THE REGION WITH VARIOUS WEAK
SHORTWAVES MOVING THROUGH THE FLOW. ONE WEAK LEAD SHORTWAVE HAS
ALREADY BEEN HEADING TOWARDS WESTERN ND...WITH SOME DECENT RADAR
RETURNS OVER THAT PART OF THE STATE. SOME LIGHT RAIN HAS BEEN
REACHING THE GROUND...ALTHOUGH NOT AS MUCH AS RADAR WOULD
INDICATE. DEW POINTS OVER THE CWA HAVE BEEN IN THE SINGLE DIGITS
TO TEENS. THE RAP AND HRRR HAVE THE PRECIP DISSIPATING AS IT MOVES
EAST...WHICH SEEMS REASONABLE GIVEN THE VERY DRY AIR. THINK THE
BETTER SHOT FOR PRECIPITATION WILL BE LATER TONIGHT AS A MORE
SOUTHERN SHORTWAVE MOVES INTO WY AND SFC LOW PRESSURE DEVELOPS
OVER WESTERN SD. THERE WILL BE SOME MID LEVEL WARM AIR
ADVECTION/FRONTOGENESIS OVER MAINLY THE SOUTHERN COUNTIES TONIGHT.
SOME OF THE MODELS HAVE SEVERAL TENTHS OF QPF TONIGHT...BUT GIVEN
HOW LONG IT WILL TAKE TO SATURATE WILL LEAN TOWARDS THE LOWER END
FOR PRECIP AMOUNTS. MODEL SOUNDINGS SHOW MOSTLY ABOVE ZERO AS THE
COLUMN SATURATES...BUT SOME SNOW MIXING IN ON THE NORTHERN EDGE OF
THE PRECIP IS NOT OUT OF THE QUESTION.
TOMORROW...THE SHORTWAVE TROUGH MOVES OUT INTO THE PLAINS...AND
THERE SHOULD BE A DECENT AMOUNT OF PRECIP OVER THE SOUTHERN
COUNTIES SPREADING NORTH AND EAST AS THE BEST MID LEVEL BAROCLINIC
ZONE LIFTS ACROSS THE AREA. CONTINUED TO KEEP LIKELY POPS FOR A
RAIN/SNOW MIX OVER THE SOUTHEASTERN COUNTIES FOR FRIDAY
MORNING...LINGERING INTO THE AFTERNOON. THE CLOUDS AND PRECIP
SHOULD KEEP TEMPS IN THE LOWER 40S IN THE EAST...BUT THINK THERE
WILL BE ENOUGH PEAKS OF SUN TO GET ABOVE 50 IN THE WESTERN
COUNTIES WHERE IT WILL BE DRIER. PRECIP WILL BEGIN TO TAPER OFF
FRIDAY NIGHT BUT KEPT SOME LOWER POPS THROUGH SATURDAY MORNING IN
OUR SOUTHEAST TO COORDINATE WITH NEIGHBORS. CLOUDS AND INCREASING
EASTERLY WINDS WILL KEEP TEMPS IN THE 30S FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 321 PM CDT THU APR 23 2015
SATURDAY AND SUNDAY...UPPER RIDGING WILL BUILD IN BRIEFLY...BUT
GIVE WAY AS THE NEXT SPLIT TROUGH BEGINS TO MOVE OUT FROM THE
WESTERN CONUS BY LATE SUNDAY. SFC HIGH PRESSURE OVER ONTARIO
SATURDAY WILL BRING EAST TO SOUTHEASTERLY WINDS WITH DRIER AIR INTO
THE CWA AND HIGHS SHOULD REACH THE 50S WITH AT LEAST SOME BREAKS
IN THE CLOUDS. TEMPS WILL BE EVEN WARMER FOR SUNDAY AS THE SFC
HIGH MOVES OFF TO THE EAST AND A TROUGH DEVELOPING OVER THE
WESTERN PLAINS STARTS SOME WARMER AIR MOVING BACK TO THE NORTH.
THE ECMWF TRIES TO BRING SOME PRECIP INTO OUR WESTERN COUNTIES FOR
SUNDAY AS THE NEXT UPPER SYSTEM APPROACHES...BUT THE OTHER MODELS
ARE A BIT SLOWER. INCLUDED SOME LOW POPS IN THE DEVILS LAKE BASIN
BUT THINK THE MAIN PRECIP WILL HOLD OFF UNTIL AFTER 00Z MONDAY.
SUNDAY NIGHT THROUGH THURSDAY...LONG WAVE UPPER LEVEL LOW PRESSURE
THAT WAS NORTH OF THE GREAT LAKES WILL MOVE OFF THE NEW ENGLAND
STATES EARLY IN THE PERIOD. BUT LONG WAVE TROUGH BECOMES RE-
ESTABLISHED OVER THE NORTHEAST STATES BY THE END OF THE PERIOD.
LONG WAVE UPPER RIDGE BUILDS OVER THE US AND CANADIAN ROCKIES THIS
PERIOD. ECMWF AND GFS WERE TRENDING FASTER THEN SLOWER OVER THE
LAST COUPLE MODEL RUNS. THE GFS IS FASTER THAN THE ECMWF. SO WILL
PREFER THE SLOWER ECMWF.
KEPT POPS FROM PREVIOUS RUN FOR MON NIGHT THROUGH TUE NIGHT.
APPROACHING UPPER LEVEL TROUGH WILL PRODUCE PRECIP FOR MON AND TUE
AND ANOTHER SHORT WAVE TROUGH IS EXPECTED WED NIGHT THROUGH THU
NIGHT.
HIGH TEMPS WERE INCREASED TWO TO FIVE DEGREES FOR MON TUE AND WED.
HIGH TEMPS DECREASED TWO TO FIVE DEGREES FOR THU FROM THIS MORNINGS
FORECAST PACKAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1256 PM CDT THU APR 23 2015
A CLEAR SKY WAS ACROSS MUCH OF THE FORECAST AREA. SOME CIRRUS CLOUDS
WERE MOVING INTO THE WESTERN ZONES. EXPECT CIRRUS CLOUDS THIS
AFTERNOON. CLOUDS SHOULD THICKEN AND LOWER THROUGH THE EVENING TO
AROUND 6 TO 9 THOUSAND FT AND AROUND 5 THOUSAND FT BY 12Z FRI. MVFR
CONDITIONS POSSIBLE FOR FRI. OTHERWISE VFR CONDITIONS EXPECTED THIS
AFTERNOON AND TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
303 PM CDT THU APR 23 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
SHOWERS THIS AFTERNOON THROUGH TONIGHT HIGHLIGHT THE SHORT TERM
FORECAST.
OUTSIDE OF THE HIGHWAY 200 CORRIDOR...THE MAJORITY OF
PRECIPITATION IS NOT REACHING THE GROUND DUE TO DRY AIR IN THE
SUB-800 MB LAYER. THE 16-18 UTC HRRR ITERATIONS HAVE THE BEST
HANDLING OF THE ONGOING PRECIPITATION...ESPECIALLY THAT WHICH IS
REACHING THE GROUND...AND WILL WEIGH HEAVILY ON THEIR SOLUTIONS
THROUGH AFTERNOON AND EVENING. THEREAFTER...THE 12 AND INCOMING 18
UTC GLOBAL AND HIGH RESOLUTION SUITES ARE IN AGREEMENT ON ELEVATED
SHOWERS DEVELOPING TONIGHT ACROSS THE JAMES AND INTO THE RED RIVER
VALLEYS BY 05 UTC WITH A MODEST LOW LEVEL JET AHEAD OF THE
SURFACE LOW ACROSS WESTERN SOUTH DAKOTA. GIVEN MARGINALLY POSITIVE
SHOWALTER VALUES...WILL NOT PUT IN THUNDER AT THIS TIME. FRIDAY
APPEARS TO BE DRY ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN
THE STRONGER LOW ACROSS THE CENTRAL PLAINS AND THE PACIFIC
NORTHWEST TROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 303 PM CDT THU APR 23 2015
A SPLIT FLOW THROUGH THE WEEKEND WITH PERIODS OF INTERACTION
BETWEEN THE SOUTHERN STREAM AND NORTHERN STREAM. THIS WILL
ULTIMATELY SET UP AN INCREASINGLY WET/UNSETTLED WEATHER PATTERN
THROUGH EARLY NEXT WEEK. TWO MAIN SHORTWAVES TO PUSH ACROSS WESTERN
AND CENTRAL NORTH DAKOTA FRIDAY NIGHT THROUGH MONDAY. THE LATEST
ECMWF IS ADVERTISING A MORE CONTINUOUS RAIN OVER THE WEEKEND INTO
MONDAY...WHILE THE GFS/CANADIAN GEM HAS A MORE DISTINCT START/END
TIME WITH EACH WAVE. UTILIZED A BLEND OF THE ABOVE MODELS ABOVE.
EXPECT A BRIEF DRYING AND WARMING TREND BY MIDWEEK...THEN A
PROGRESSIVE AND POSSIBLY UNSETTLED WEATHER PATTERN SETTING UP LATE
IN THE EXTENDED.
FOR FRIDAY NIGHT THROUGH SATURDAY...A TRANSITORY 700MB-500MB RIDGE
DEVELOPS OUT AHEAD OF AN APPROACHING SHORTWAVE TROUGH SLIDING INTO
THE NORTHERN ROCKIES. THIS SHOULD KEEP CONDITIONS DRY FOR MOST AREAS
FRIDAY NIGHT BEFORE EAST TO SOUTHEAST WINDS ADVECT AN AREA OF
MOISTURE INTO THE WEST. THIS MOISTURE WILL CONVERGE INTO AN
APPROACHING SURFACE COLD FRONT IN EASTERN MONTANA. THUS POPS BECOME
LIKELY THEN CATEGORICAL SATURDAY IN THE WEST...WITH DRIER CONDITIONS
IN THE EAST AS MID LEVEL RIDGING REMAINS INTACT UNTIL 00Z SUNDAY.
SATURDAY NIGHT THROUGH MONDAY NIGHT...AS MENTIONED ABOVE THERE ARE
DIFFERENCES IN THE ECMWF AND GFS/GEM...ESPECIALLY SATURDAY NIGHT
THROUGH SUNDAY. PER GFS/GEM...THE SURFACE LOW/COLD FRONT AND SHORTWAVE
MOVE INTO SOUTHERN CANADA WITH SHOWERS DIMINISHING SATURDAY NIGHT
INTO SUNDAY. THE TRAILING COLD FRONT STALLS UNDER A SOUTHWEST FLOW
ALOFT...WITH LOW LEVEL SOUTH TO SOUTHEAST WINDS FEEDING MOISTURE
INTO NORTH DAKOTA. THE GFS/GEM MODELS TREND TOWARD A CESSATION TO
THE PRECIPITATION UNTIL SUNDAY NIGHT WHEN THE THE FRONT BECOMES
RE-ENERGIZED AS THE NEXT SHORTWAVE TROUGH APPROACHES. WITH THE
SURFACE COLD FRONT AND SOUTHERN STREAM MOISTURE ALREADY IN
PLACE...THIS SETS THE STAGE FOR A MORE WIDESPREAD PRECIPITATION
EVENT SUNDAY NIGHT THROUGH MONDAY. AS MENTIONED ABOVE THE LATEST
ECMWF REALLY DOES NOT STOP THE PRECIPITATION WITH THE INITIAL
SHORTWAVE...RATHER KEEPS THE SURGE MAINLY CONTINUOUS IN THE WEST AND
SLOWLY SPREADS IT EAST AND NORTH THROUGH MONDAY. TOTAL PRECIPITATION
AMOUNTS COULD RANGE BETWEEN A HALF INCH TO ONE INCH IN THE WEST TO
AROUND A QUARTER OF AN INCH IN CENTRAL NORTH DAKOTA THROUGH MONDAY NIGHT.
MONDAY NIGHT THROUGH THURSDAY...GOOD AGREEMENT THAT PRECIPITATION
WILL BE EAST OF THE JAMES RIVER VALLEY BY 12Z TUESDAY FOLLOWED BY
UPPER RIDGING TUESDAY AND WEDNESDAY. WARM AIR ADVECTION RAMPS UP
LATE TUESDAY INTO WEDNESDAY...AHEAD OF AN ADVANCING COLD FRONT WHICH
IS FORECAST TO CROSS SOUTHERN CANADA WEDNESDAY AFTERNOON/EVENING. THE GFS
SHOWS SOME LIGHT PRECIPITATION DEVELOPING IN THE NORTH BEHIND THE
FRONT WEDNESDAY AFTERNOON. THE ECMWF IS ABOUT 6HRS SLOWER WITH THE
COLD FRONT...NOT ARRIVING INTO THE NORTHWEST UNTIL AROUND 00Z
THURSDAY. THURSDAY LOOKS DRY...ALTHOUGH THIS MAY BE BRIEF AS
THE NEXT SYSTEM IS ALREADY APPROACHING THURSDAY NIGHT INTO FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT |247 PM CDT THU APR 23 2015
SCATTERED RAIN SHOWERS ACROSS WESTERN AND CENTRAL NORTH DAKOTA
THIS AFTERNOON WILL CONTINUE TO MOVE EAST AND FADE WITH
SUNSET...BEFORE ADDITIONAL SHOWERS FORM TONIGHT NEAR KJMS AFTER 05
UTC. MVFR CONDITIONS IN RAIN POSSIBLE. OTHERWISE...VFR CONDITIONS
FOR THE 18 UTC CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AYD
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS NORMAN OK
418 PM CDT THU APR 23 2015
.DISCUSSION...
STRATUS HAS INHIBITED HEATING ACROSS THE ENTIRE AREA TODAY WITH
PERSISTENT ESE LOW LEVEL FLOW BEHIND THE FRONT. DO NOT EXPECT ANY
STORMS BEFORE 00Z. HOWEVER...LATER TONIGHT A NOCTURNAL LLJ WILL
DEVELOP OVER CENTRAL OK ISENTROPIC ASCENT WILL FOLLOW. IN
ADDITION...A SUBTLE MID LEVEL SHORTWAVE TROUGH WILL ALSO MOVE OUT
OF THE PANHANDLE ~06Z. NAM AND RAP SOUNDINGS ALSO INDICATE AROUND
1500 J/KG OF ELEVATED CAPE NEAR 06-09Z WITH PLENTY OF DEEP LAYER
SHEAR PRESENT. WOULD NOT BE SURPRISED IF A COUPLE OF SEVERE
STORMS DEVELOP OVERNIGHT ACROSS CENTRAL/N CENTRAL OK. THEN...LATE
TONIGHT THROUGH LATE TOMORROW MORNING A MID LEVEL SHORTWAVE
TROUGH WILL LIFT OUT OF WEST TEXAS AND APPROACH THE SE RED RIVER
VALLEY. MODELS CONTINUE TO INDICATE SCATTERED ACTIVITY OVER OUR SE
ZONES THROUGH MOST OF THE DAY.
THE PREVIOUS WILL LIKELY LIMIT INSTABILITY AT LEAST ALONG THE
SOUTHERN HALF OF THE DRYLINE FRI AFT/EVE. FURTHER NORTH ALONG THE
DRYLINE...SOMEWHERE FROM AROUND OKC TO TO SWO TO PNC...THERE MAY
BE ENOUGH INSTABILITY FOR A FEW STORMS TO DEVELOP BEFORE THEY MOVE
EAST OUT OF AREA DURING THE EVENING HOURS. IF STORMS DO MANAGE TO
DEVELOP LATE TOMORROW AFTERNOON ALONG AND EAST OF I35...THEY WILL
LIKELY BECOME SEVERE WITH DAMAGING WINDS...HAIL...AND PERHAPS
TORNADOES POSSIBLE.
DRIER CONDITIONS ARE EXPECTED SATURDAY AND TEMPS WILL CLIMB WELL
ABOVE AVERAGE OVER THE SW AS STRONG DOWNSLOPE FLOW DEVELOPS AHEAD
OF A COLD FRONT SLOWLY STALLING OUT. MAXTS IN THE LOW 90S APPEAR
POSSIBLE FOR PORTIONS OF WESTERN N TX. THE ATTENTION THEN TURNS TO
LATE SUNDAY THROUGH MONDAY AS A FAIRLY DEEP UPPER LOW TRAVERSES NM
AND MOVES INTO THE SOUTHERN PLAINS MON AM. WILL CONTINUE TO SLOWLY
INCREASE POPS FOR EARLY NEXT WEEK WITH THIS SYSTEM. IT WILL DRY
OUT AND COOL OFF TUES-WED BEHIND A COLD FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 80 56 85 / 40 30 20 0
HOBART OK 61 84 55 87 / 20 10 0 0
WICHITA FALLS TX 64 84 58 89 / 20 20 10 0
GAGE OK 58 81 52 84 / 20 20 10 0
PONCA CITY OK 59 81 58 83 / 30 30 20 10
DURANT OK 63 79 62 88 / 30 70 40 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/03
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1004 PM CDT FRI APR 24 2015
.UPDATE...HAVE UPDATED SEVERE THUNDERSTORM WATCH AREA TO REMOVE
COUNTIES WEST OF CURRENT ACTIVITY AND HAVE ADDED SOME
KARNES...DEWITT...LAVACA...AND GONZALES COUNTIES DOWNSTREAM.
RAIN/THUNDERSTORM CHANCES WERE ENHANCED WHERE CURRENT AND
PROJECTED ACTIVITY IS EXPECTED OVER THE NEXT 3-6 HOURS.
UNCERTAINTY REMAINS CONCERNING THE HEAVY RAINFALL POTENTIAL AND
AND WILL MAINTAIN THE FLASH FLOOD WATCH FOR NOW BUT WILL LIKELY BE
REVISITED IN NEXT COUPLE HOURS DEPENDING ON CONVECTIVE EVOLUTION.
MORE DETAILS CAN BE FOUND BELOW ON FOR THE NEXT 6-12 HOUR TIME
FRAME.
&&
.DISCUSSION...DECENT SHORTWAVE TROUGHING ACROSS THE SOUTH CENTRAL
PLAINS ALONG WITH IMPULSES EMBEDDED IN THE BRISK H5-H3 SW FLOW
OVER THE REGION HAS LEAD TO SOME STRONG TO SEVERE STORM
DEVELOPMENT ACROSS THE RIO GRANDE PLAINS AND SOME COUNTIES
EASTWARD. MUCAPE VALUES REMAIN NEAR 3000 J/KG BUT IT APPEAR PER
MESO ANALYSIS THAT SOME LOW-LVL STABILIZATION IS BEGINNING TO
OCCUR. DESPITE THIS...AMPLE DIVERGENCE OVER THE REGION /70-90 KT
H5-H3 WIND FLOW/ LEADING TO NEAR 70 KT OF EFFECTIVE SHEAR IS ABLE
TO SUPPORT ROTATING UPDRAFTS AND ENHANCE A HAIL AND STRAIGHT-LINE
DAMAGINGWIND RISK. THE TORNADO RISK WHILE LIMITED BEFORE WILL
EVEN FURTHER REDUCE AS STORMS ENTER NON-FAVORABLE SRH FIELDS.
STORMS THAT WERE BACK WEST IN ZAVALA AND DIMMIT COUNTIES AROUND
8PM HAD ENHANCED EFFECTIVE SRH NEAR 200 M2/S2. IT APPEARS A MINI
SUPERCELL DEVELOPED ALONG THE LEADING EDGE OF A FLANKING BOUNDARY
ATTENDANT TO ANOTHER SUPERCELL THAT WAS ABLE TO INGEST ENHANCED
LOW-LVL HELICITY FOR THE FUNNEL AND LIKELY BRIEF TORNADO THAT
OCCURRED. AGAIN...THIS RISK IS DIMINISHED QUICKLY GIVEN
UNFAVORABLE LOW-LVL SHEAR IN PLACE. SOME QUARTER SIZE HAIL...BRIEF
SEVERE WIND GUSTS TO 60 MPH AND HEAVY RAIN WILL REMAIN A
POSSIBILITY THROUGH THE LATE EVENING INTO EARLY SATURDAY MORNING.
THE HRRR CONTINUES TO TRY AND MERGE THESE CELLS ACROSS ATASCOSA
COUNTY INTO A LINE ACROSS THE SOUTHEAST PRAIRIE COUNTIES...WHILE
THIS IS PLAUSIBLE...IT REDUCES THE OVERALL RISK FOR WIDESPREAD
HEAVY RAIN. SOME SHORT TERM MODELS SUGGEST NEW DEVELOPMENT UPWIND
OF CURRENT ACTIVITY BUT CONFIDENCE IS LOW IS THIS SCENARIO. IF
CURRENT TRENDS HOLD...THE FLASH FLOOD WATCH MAY BE CUT BACK OR
CANCELLED IN ANOTHER UPDATE THIS EVENING. BULK OF THE ACTIVITY
SHOULD MOVE EAST OF THE REGION BY 3AM...IF NOT SOONER...AND THE
AREA BE CLEAR OF ALL HAZARDS BY THAT TIME.
ALLEN
&&
.PREV DISCUSSION... /ISSUED 656 PM CDT FRI APR 24 2015/
AVIATION...
/00Z TAFS/
ONGOING CONVECTION JUST TO THE SOUTHEAST OF KDRT WILL CONTINUE TO
MOVE TO THE NORTHEAST. NEW STORMS ARE EXPECTED TO DEVELOP WITHIN
THE NEXT HOUR OR TWO AND APPROACH KSAT AND KSSF AROUND 01Z AND 02Z
OVER KAUS. HIRES SOLUTIONS CLEAR THE KAUS AREA AFTER 04Z BUT KEEP
SHOWERS/STORMS ACROSS SAN ANTONIO THROUGH 05Z SATURDAY. SOME OF
THESE STORMS COULD BE STRONG TO SEVERE AS THEY MOVE ACROSS THE
I-35 CORRIDOR. AT THIS TIME...WILL NOT INCLUDE THUNDERSTORM WIND
GUSTS AS STRONGER STORMS ARE FORECAST TO STAY TO THE SOUTHEAST AND
SOUTH OF THE TERMINALS. MVFR CONDITIONS ARE EXPECTED DURING THE
STORMS PERIOD...BUT CAN NOT RULE OUT IFR CIGS FOR A SHORT PERIOD
OF TIME. AFTER THE STORMS PUSH AWAY OVERNIGHT...WINDS WILL BECOME
LIGHT AND VARIABLE AND REMAIN THROUGH LATE SATURDAY MORNING. VFR
CONDITIONS ARE EXPECTED ACROSS THE I-35 SITES AFTER 13Z WHILE KDRT
REMAINS VFR THROUGH THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 256 PM CDT FRI APR 24 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
.LOCALLY HEAVY RAINFALL LEADING TO FLASH FLOODING POSSIBLE
TONIGHT ACROSS SOUTHERN AND EASTERN AREAS...
STARTING TO SEE SOME RECOVERY AFTER THE EARLY MORNING MCS. SOME
POCKETS OF CLEARING ARE BEGINNING TO TAKE PLACE ACROSS THE
SOUTHWEST CWA AND FAR WESTERN VAL VERDE COUNTY...AND ALSO SEEING
CONVECTION BEGINNING TO DEVELOP ALONG THE HIGHER TERRAIN IN
MEXICO. ANALYSES INDICATES LOW LEVEL THETA-E RIDGE AXIS ALONG AND
JUST WEST OF THE RIO GRANDE...STILL SOME CIN TO OVERCOME JUST EAST
OF THE RIO GRANDE. WITH ADDITIONAL CLEARING DO EXPECT THE POTENTIAL
FOR SOME STORMS TO CROSS INTO MAVERICK...KINNEY AND/OR VAL VERDE
COUNTIES THROUGH 6 PM.
MODELS ARE IN GENERAL AGREEMENT WITH BROAD MID AND UPPER LEVEL
FORCING INCREASING WEST TO EAST THIS EVENING WITH APPROACH OF
SHORTWAVE...ALONG WITH BROAD ENTRANCE REGION TO UPPER LEVEL JET
STREAK LOCATED OVER THE CWA. SEVERAL HI RES MODELS INDICATE
SCATTERED TO NUMEROUS SHOWERS AND STORMS DEVELOPING EARLY THIS
EVENING SOUTHWEST OF SAN ANTONIO AND SPREADING NORTHEAST THROUGH
THE SOUTHERN AND EASTERN AREAS OF THE CWA THROUGH THE EVENING AND
OVERNIGHT HOURS. IN ADDITION...ARW/NMM/HRRR INDICATING STORMS
DEVELOPING OVER THE SJT CWA CLIPPING FAR NORTHERN AREAS UP NEAR
BURNET.
SUFFICIENT DEEP LAYER SHEAR AND STEEP ELEVATED LAPSE RATES/CAPE
WARRANT THE RISK FOR SOME STRONG TO SEVERE STORMS THIS EVENING...
PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS. BUT THE BIGGER
THREAT MAY BE LOCALLY HEAVY RAINFALL ESPECIALLY ALONG AND SOUTH OF
I-10/US 90. VERY HIGH PWAT AIRMASS STILL POOLED IN THIS REGION...
AND MODEL CONSENSUS OF 1 TO 2 INCHES OF QPF WITH ISOLATED POCKETS
OF 3 TO 4 OCCURRING BETWEEN THE CRP/EWX CWA BOUNDARY AND I-10. A
FLASH FLOOD WATCH HAS BEEN ISSUED FOR A PORTION OF THIS AREA...
COINCIDING WHERE HEAVY RAINFALL HAS ALREADY OCCURRED THE PAST
SEVERAL DAY. THE WATCH GOES AS FAR NORTH AS BASTROP AND LEE
COUNTIES (NOT INCLUDING TRAVIS OR WILLIAMSON)...DESPITE LESSER
AMOUNTS FORECAST IN THIS AREA. THIS IS OUT OF AN ABUNDANCE OF
CAUTION AS SOILS ARE SATURATED OVER MUCH OF THESE AREA...WITH
ONGOING FLOODING PROBLEMS CONTINUING IN BASTROP COUNTY.
PRECIP SHOULD EXIT TO THE EAST OF THE AREA EARLY SATURDAY MORNING.
A WEAK SURFACE BOUNDARY MOVES INTO THE AREA SATURDAY...WITH
SLIGHTLY DRIER AIR ALONG AND WEST OF I-35. A POOL OF MOISTURE
WILL STILL REMAIN ACROSS THE FAR SOUTHEAST ZONES...WHERE ISOLATED
SHOWERS OR THUNDERSTORMS WILL BE A POSSIBILITY SATURDAY AFTERNOON.
RUNYEN
LONG TERM (SUNDAY THROUGH FRIDAY)...THE BOUNDARY MOVES BACK WEST
OF THE I-35 CORRIDOR SUNDAY AND MONDAY...AS AN UPPER LEVEL LOW
DEEPENS ACROSS NEW MEXICO AND THE PANHANDLE. LOW CHANCES FOR
SHOWERS AND STORMS BOTH SUNDAY AND MONDAY ACROSS THE CENTRAL AND
EASTERN CWA AS WEAK FORCING INTERACTS WITH MOISTURE POOLED OVER
THE AREA. EVENTUALLY A COLD FRONT CLEARS THROUGH THE CWA ON
TUESDAY...AND DEEPER NORTHWEST FLOW DEVELOPS OVER THE AREA
WEDNESDAY THROUGH FRIDAY AS THE UPPER LEVEL TROUGH AXIS MOVES
EAST. LOOK FOR MORE SEASONAL TEMPS AND DRY CONDITIONS WEDNESDAY
THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 67 89 66 86 66 / 50 - 0 30 30
AUSTIN BERGSTROM INTL AIRPORT 66 88 63 85 65 / 60 10 - 30 30
NEW BRAUNFELS MUNI AIRPORT 67 88 65 86 67 / 80 10 - 30 30
BURNET MUNI AIRPORT 63 86 61 85 62 / 40 0 0 30 30
DEL RIO INTL AIRPORT 63 88 64 90 63 / 10 0 - - 20
GEORGETOWN MUNI AIRPORT 65 88 63 85 65 / 50 0 0 30 30
HONDO MUNI AIRPORT 65 88 65 88 64 / 70 - - 20 30
SAN MARCOS MUNI AIRPORT 67 87 64 85 66 / 70 10 - 30 30
LA GRANGE - FAYETTE REGIONAL 70 87 67 85 69 / 80 20 - 30 20
SAN ANTONIO INTL AIRPORT 68 89 67 87 67 / 80 10 - 30 30
STINSON MUNI AIRPORT 69 88 66 87 67 / 80 10 - 30 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 5 AM CDT SATURDAY FOR THE FOLLOWING
COUNTIES: ATASCOSA...BASTROP...BEXAR...CALDWELL...DE WITT...
FAYETTE...FRIO...GONZALES...GUADALUPE...KARNES...LAVACA...LEE...
MEDINA...WILSON.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...15
PUBLIC SERVICE/DATA COLLECTION...01
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
310 AM CDT THU APR 23 2015
.UPDATE...
PATCHY FOG HAS DEVELOPED AND EXPECT IT WILL CONTINUE AS MOST
PLACES ARE SATURATED. HAVE ADDED FOG FOR THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 109 AM CDT THU APR 23 2015/
AVIATION... /06Z TAF UPDATE/
SURFACE WINDS HAVE BECOME MOSTLY DECOUPLED ALONG HIGHWAY 90 TO
PROMOTE MAINLY IFR CONDITIONS AT DRT/SAT/SSF. RELATIVELY LIGHT
LOW LEVEL WINDS OF 15-20 KNOTS OFF THE DECK AS SHOWN IN VAD WIND
DATA WOULD SUGGEST A FEW AREAS SHOWING LIGHT FOG ALONG HIGHWAY
90...BUT CIGS ARE MORE LIKELY TO FALL INTO THE LIFR CATEGORY AS
DECOUPLING CONTINUES INTO DAYBREAK. THE SURFACE MOISTURE GRADIENT
WOULD SUGGEST GRADUAL MOISTURE ADVECTION TO HELP KEEP IFR CIGS IN
THROUGH MID MORNING AND MOST AREAS IN MVFR CONDITIONS INTO THE
EARLY AFTERNOON. THERE SHOULD BE A GOOD CHANCE FOR SOME VFR SKIES
IN THE LATE AFTERNOON AND EARLY EVENING BEFORE CLOUDS RETURN. CAP
STRENGTH IS EXPECTED TO HOLD OFF MOST CONVECTION INTO THIS
EVENING...BUT FUTURE TAF UPDATES WILL LIKELY NEED TO ADD A TEMPO
OR POSSIBLE PREVAILING THUNDERSTORM CATEGORY IN THE LAST 12 TO 18
HOURS OF THE FORECAST.
PREV DISCUSSION... /ISSUED 733 PM CDT WED APR 22 2015/
UPDATE...
CURRENT FORECAST IS IN DECENT SHAPE. WILL LEAVE 20/30 POPS IN THE
FORECAST BUT OVERALL CHANCES FOR ADDITIONAL PRECIP IS LOW GIVEN
THE ATMOSPHERE IS PRETTY WORKED OVER FROM THE EARLIER CONVECTION.
AREAS SOUTH OF SAN ANTONIO RECEIVED BETWEEN 1-2 INCHES ACROSS A
LARGE AREA. OTHERWISE...MADE MINOR ADJUSTMENTS TO THE HOURLY
GRIDS FOR CURRENT TRENDS.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 231 PM CDT WED APR 22 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SEMI ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS FOLLOWED BY A
FRONT THIS WEEKEND THEN DRYING OUT EARLY NEXT WEEK.
AS OF 2 PM THERE IS A MULTICELL CLUSTER OF THUNDERSTORMS
APPROACHING BEXAR COUNTY AND SAN ANTONIO. THE HRRR TAKES THIS
COMPLEX AS WELL AS OTHER SHOWERS AND THUNDERSTORMS OUT AHEAD OF IT
EASTWARD IMPACTING A BASTROP SOUTH TO GONZALES AND KENEDY LINE.
MODEL SOUNDINGS FROM THE NAM SHOW AN UNCAPPED ATMOSPHERE ALONG
AND EAST OF I-35 THIS AFTERNOON WITH 1000-3000 J/KG OF CAPE AND
50-60 KNOTS OF SHEAR. THIS MEANS THAT THIS COMPLEX OF STORMS IS
MOVING INTO A VERY GOOD ENVIRONMENT FOR STRONG TO SEVERE STORMS.
WE CONTINUE UNDER A SLIGHT RISK FROM SPC THIS AFTERNOON ALONG AND
EAST OF US HWY 281. WE HAVE ALSO SEEN HEAVY RAINFALL RATES OUT OF
THE ONGOING STORMS SO SOME LOCALIZED FLOODING IS NOT OUT OF THE
QUESTION WITH THE STRONGER STORMS. THE MAIN THREATS WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ANY SEVERE WEATHER THAT DOES OCCUR
THIS AFTERNOON AND EVENING. THE THREAT FOR TORNADOES REMAINS LOW
AS LOW LEVEL SHEAR IS WEAK.
OTHER FEATURES IN PLAY TODAY ARE A STATIONARY FRONT ACROSS THE
RED RIVER IN NORTH TEXAS AND THE DRYLINE OUT IN WEST
TEXAS...ALTHOUGH OTHER THAN AN ISOLATED DRYLINE STORM NEITHER WILL
IMPACT OUR WEATHER MUCH. GENERAL RIDGING IS FORECAST TO TAKE
PLACE THROUGH THE PERIOD AS HIGH PRESSURE OVER NORTHERN MEXICO
MOVES SLOWLY EAST. CONVECTION WILL DECREASE OVERNIGHT TONIGHT AND
WITH NORTHWEST FLOW CONTINUING ONLY SLIGHT CHANCES FOR
PRECIPITATION ARE FORECAST FOR THURSDAY THROUGH THURSDAY EVENING.
MODEL SOUNDINGS SHOW A STRONG CAP ACROSS MOST OF SOUTH CENTRAL
TEXAS DURING THE DAY TOMORROW. BY LATE IN THE AFTERNOON MODELS DO
WEAKEN THE CAP WHICH COULD ALLOW FOR SOME ISOLATED SHOWERS AND
THUNDERSTORMS. AGAIN...CONDITIONS WILL BE FAVORABLE TOMORROW FOR
SEVERE WEATHER WITH 50 KNOTS OF UPPER LEVEL SHEAR AND 2000-3000
J/KG OF CAPE. THE DAY 2 OUTLOOK FROM SPC HAS THE WHOLE AREA IN A
SLIGHT RISK FOR TOMORROW...WITH LARGE HAIL AND DAMAGING WINDS
AGAIN THE PRIMARY THREATS.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODELS ARE IN AGREEMENT THAT THURSDAY NIGHT THROUGH FRIDAY MORNING
WILL BE A PERIOD OF HIGHER QPF...HIGHER RAIN CHANCES. THE GREATEST
CHANCES FOR RAIN WILL BE ALONG THE RIO GRANDE PLAINS THURSDAY
NIGHT SPREADING TO AREAS ALONG AND EAST OF I-35 FOR FRIDAY. AN
UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL PROVIDE THE
NEEDED LIFT FOR THIS PRECIPITATION. CHANCES OF SEVERE WEATHER
CONTINUE INTO FRIDAY WITH THE BEST INSTABILITY LOCATED ALONG AND
WEST OF I-35. AS THE TROUGH MOVES OFF TO THE EAST AND NORTHEAST
SATURDAY CHANCES FOR RAIN WILL DECREASE THROUGH THE DAY. THE NEXT
FRONT WILL MOVE THROUGH SUNDAY INTO MONDAY. THE GFS AND NEW 12Z
ECMWF DISAGREE BY ABOUT 24 ON THE TIMING OF THIS FRONT...WITH THE
ECMWF BRING THE SLOWER OF THE TWO. WILL GO WITH A PERSISTENCE
FORECAST AND CHANCE POPS FOR SUNDAY AND MONDAY...DRYING OUT
TUESDAY. THE ONE BENEFIT OF THIS FRONT IS IT WILL COOL THE AREA
BACK DOWN INTO THE 70S FOR HIGHS FOR A FEW DAYS BY THE MIDDLE OF
NEXT WEEK.
TREADWAY
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 88 71 84 67 88 / 30 30 60 40 20
AUSTIN BERGSTROM INTL AIRPORT 86 70 84 66 87 / 30 30 60 40 20
NEW BRAUNFELS MUNI AIRPORT 88 70 85 67 88 / 20 40 50 50 20
BURNET MUNI AIRPORT 87 68 83 63 87 / 30 40 60 30 10
DEL RIO INTL AIRPORT 89 68 87 64 89 / 20 40 30 30 10
GEORGETOWN MUNI AIRPORT 86 70 84 65 88 / 30 40 60 30 10
HONDO MUNI AIRPORT 87 70 84 66 88 / 20 50 40 50 20
SAN MARCOS MUNI AIRPORT 87 69 84 67 86 / 20 40 50 50 20
LA GRANGE - FAYETTE REGIONAL 86 71 84 69 86 / 20 30 40 40 20
SAN ANTONIO INTL AIRPORT 88 71 85 68 88 / 20 40 50 50 20
STINSON MUNI AIRPORT 87 71 85 69 88 / 20 40 50 50 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
109 AM CDT THU APR 23 2015
.AVIATION... /06Z TAF UPDATE/
SURFACE WINDS HAVE BECOME MOSTLY DECOUPLED ALONG HIGHWAY 90 TO
PROMOTE MAINLY IFR CONDITIONS AT DRT/SAT/SSF. RELATIVELY LIGHT
LOW LEVEL WINDS OF 15-20 KNOTS OFF THE DECK AS SHOWN IN VAD WIND
DATA WOULD SUGGEST A FEW AREAS SHOWING LIGHT FOG ALONG HIGHWAY
90...BUT CIGS ARE MORE LIKELY TO FALL INTO THE LIFR CATEGORY AS
DECOUPLING CONTINUES INTO DAYBREAK. THE SURFACE MOISTURE GRADIENT
WOULD SUGGEST GRADUAL MOISTURE ADVECTION TO HELP KEEP IFR CIGS IN
THROUGH MID MORNING AND MOST AREAS IN MVFR CONDITIONS INTO THE
EARLY AFTERNOON. THERE SHOULD BE A GOOD CHANCE FOR SOME VFR SKIES
IN THE LATE AFTERNOON AND EARLY EVENING BEFORE CLOUDS RETURN. CAP
STRENGTH IS EXPECTED TO HOLD OFF MOST CONVECTION INTO THIS
EVENING...BUT FUTURE TAF UPDATES WILL LIKELY NEED TO ADD A TEMPO
OR POSSIBLE PREVAILING THUNDERSTORM CATEGORY IN THE LAST 12 TO 18
HOURS OF THE FORECAST.
&&
.PREV DISCUSSION... /ISSUED 733 PM CDT WED APR 22 2015/
UPDATE...
CURRENT FORECAST IS IN DECENT SHAPE. WILL LEAVE 20/30 POPS IN THE
FORECAST BUT OVERALL CHANCES FOR ADDITIONAL PRECIP IS LOW GIVEN
THE ATMOSPHERE IS PRETTY WORKED OVER FROM THE EARLIER CONVECTION.
AREAS SOUTH OF SAN ANTONIO RECEIVED BETWEEN 1-2 INCHES ACROSS A
LARGE AREA. OTHERWISE...MADE MINOR ADJUSTMENTS TO THE HOURLY
GRIDS FOR CURRENT TRENDS.
HAMPSHIRE
PREV DISCUSSION... /ISSUED 231 PM CDT WED APR 22 2015/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
SEMI ACTIVE WEATHER PATTERN FOR THE NEXT FEW DAYS FOLLOWED BY A
FRONT THIS WEEKEND THEN DRYING OUT EARLY NEXT WEEK.
AS OF 2 PM THERE IS A MULTICELL CLUSTER OF THUNDERSTORMS
APPROACHING BEXAR COUNTY AND SAN ANTONIO. THE HRRR TAKES THIS
COMPLEX AS WELL AS OTHER SHOWERS AND THUNDERSTORMS OUT AHEAD OF IT
EASTWARD IMPACTING A BASTROP SOUTH TO GONZALES AND KENEDY LINE.
MODEL SOUNDINGS FROM THE NAM SHOW AN UNCAPPED ATMOSPHERE ALONG
AND EAST OF I-35 THIS AFTERNOON WITH 1000-3000 J/KG OF CAPE AND
50-60 KNOTS OF SHEAR. THIS MEANS THAT THIS COMPLEX OF STORMS IS
MOVING INTO A VERY GOOD ENVIRONMENT FOR STRONG TO SEVERE STORMS.
WE CONTINUE UNDER A SLIGHT RISK FROM SPC THIS AFTERNOON ALONG AND
EAST OF US HWY 281. WE HAVE ALSO SEEN HEAVY RAINFALL RATES OUT OF
THE ONGOING STORMS SO SOME LOCALIZED FLOODING IS NOT OUT OF THE
QUESTION WITH THE STRONGER STORMS. THE MAIN THREATS WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ANY SEVERE WEATHER THAT DOES OCCUR
THIS AFTERNOON AND EVENING. THE THREAT FOR TORNADOES REMAINS LOW
AS LOW LEVEL SHEAR IS WEAK.
OTHER FEATURES IN PLAY TODAY ARE A STATIONARY FRONT ACROSS THE
RED RIVER IN NORTH TEXAS AND THE DRYLINE OUT IN WEST
TEXAS...ALTHOUGH OTHER THAN AN ISOLATED DRYLINE STORM NEITHER WILL
IMPACT OUR WEATHER MUCH. GENERAL RIDGING IS FORECAST TO TAKE
PLACE THROUGH THE PERIOD AS HIGH PRESSURE OVER NORTHERN MEXICO
MOVES SLOWLY EAST. CONVECTION WILL DECREASE OVERNIGHT TONIGHT AND
WITH NORTHWEST FLOW CONTINUING ONLY SLIGHT CHANCES FOR
PRECIPITATION ARE FORECAST FOR THURSDAY THROUGH THURSDAY EVENING.
MODEL SOUNDINGS SHOW A STRONG CAP ACROSS MOST OF SOUTH CENTRAL
TEXAS DURING THE DAY TOMORROW. BY LATE IN THE AFTERNOON MODELS DO
WEAKEN THE CAP WHICH COULD ALLOW FOR SOME ISOLATED SHOWERS AND
THUNDERSTORMS. AGAIN...CONDITIONS WILL BE FAVORABLE TOMORROW FOR
SEVERE WEATHER WITH 50 KNOTS OF UPPER LEVEL SHEAR AND 2000-3000
J/KG OF CAPE. THE DAY 2 OUTLOOK FROM SPC HAS THE WHOLE AREA IN A
SLIGHT RISK FOR TOMORROW...WITH LARGE HAIL AND DAMAGING WINDS
AGAIN THE PRIMARY THREATS.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODELS ARE IN AGREEMENT THAT THURSDAY NIGHT THROUGH FRIDAY MORNING
WILL BE A PERIOD OF HIGHER QPF...HIGHER RAIN CHANCES. THE GREATEST
CHANCES FOR RAIN WILL BE ALONG THE RIO GRANDE PLAINS THURSDAY
NIGHT SPREADING TO AREAS ALONG AND EAST OF I-35 FOR FRIDAY. AN
UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL PROVIDE THE
NEEDED LIFT FOR THIS PRECIPITATION. CHANCES OF SEVERE WEATHER
CONTINUE INTO FRIDAY WITH THE BEST INSTABILITY LOCATED ALONG AND
WEST OF I-35. AS THE TROUGH MOVES OFF TO THE EAST AND NORTHEAST
SATURDAY CHANCES FOR RAIN WILL DECREASE THROUGH THE DAY. THE NEXT
FRONT WILL MOVE THROUGH SUNDAY INTO MONDAY. THE GFS AND NEW 12Z
ECMWF DISAGREE BY ABOUT 24 ON THE TIMING OF THIS FRONT...WITH THE
ECMWF BRING THE SLOWER OF THE TWO. WILL GO WITH A PERSISTENCE
FORECAST AND CHANCE POPS FOR SUNDAY AND MONDAY...DRYING OUT
TUESDAY. THE ONE BENEFIT OF THIS FRONT IS IT WILL COOL THE AREA
BACK DOWN INTO THE 70S FOR HIGHS FOR A FEW DAYS BY THE MIDDLE OF
NEXT WEEK.
TREADWAY
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 70 85 67 87 65 / 40 60 30 20 -
AUSTIN BERGSTROM INTL AIRPORT 70 84 66 87 63 / 40 50 30 20 -
NEW BRAUNFELS MUNI AIRPORT 71 85 67 87 64 / 40 50 40 30 -
BURNET MUNI AIRPORT 68 84 64 86 63 / 40 60 20 - -
DEL RIO INTL AIRPORT 68 88 64 89 64 / 50 30 30 - -
GEORGETOWN MUNI AIRPORT 70 84 65 87 63 / 40 60 20 10 -
HONDO MUNI AIRPORT 71 85 66 88 63 / 40 40 50 20 -
SAN MARCOS MUNI AIRPORT 70 84 67 86 64 / 40 50 40 30 -
LA GRANGE - FAYETTE REGIONAL 72 85 69 86 66 / 30 50 40 30 -
SAN ANTONIO INTL AIRPORT 71 85 68 88 66 / 40 50 50 30 -
STINSON MUNI AIRPORT 71 85 69 87 65 / 40 40 50 30 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1153 PM CDT WED APR 22 2015
.DISCUSSION...
06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
WEAKENING WINDS WITHIN A SLIGHTLY MORE MOIST RESIDENT AIR MASS HAS
THIS TAF TRENDING TOWARDS LOW END MVFR TO (TEMPO) IFR EARLY MORNING
CEILINGS. ALTHOUGH RECENT MODEL RUNS HAVE BEEN TOO AGGRESSIVE ON
LOWERING DECKS INTO (L)IFR...THE LARGE SCALE SET-UP OF GENERAL
HIGH PRESSURE OVER THE REGION WILL SET AN ENVIRONMENT MORE
CONDUCIVE FOR THE LOWERING OF BKN-OVC DECKS AND POSSIBLE BRIEF
MVFR BR BEGINNING THURSDAY MORNING...A HIGHER PROB OF IT RE-OCCURRING
LATE THURSDAY NIGHT INTO FRIDAY MORNING. THERE IS A SLIGHT CHANCE
FOR THURSDAY PM CONVECTION BUT TOO LOW AT THE MOMENT TO MENTION
WITHIN THIS PACKAGE. CONVECTIVE CHANCES WILL INCREASE FRIDAY...BUT
RECENT MODEL RUNS HAVE THE GREATEST IMPACT FOR INCLEMENT WEATHER
FOCUSED OFF TO THE NORTH OF THE FORECAST AREA. 31
&&
.PREV DISCUSSION... /ISSUED 937 PM CDT WED APR 22 2015/
DISCUSSION...
WOW! THE SUPERCELL THAT MOVED OFF THE COAST ACROSS THE SAN ANTONIO
BAY AREA EARLIER THIS EVENING MADE IT ALL THE WAY OVER TO BUOY 42019...
AND AT 729 PM CDT PRODUCED A WIND GUST OF 76 KNOTS (87 MPH)! THIS WAS
THE SAME STORM THAT EARLIER PRODUCED LARGE HAIL AND WIND DAMAGE ALONG
THE WEST END OF SAN ANTONIO BAY (REFUGIO AND ARANSAS COUNTY AREA).
THERE WILL CONTINUE TO BE A CHANCE OF SHOWERS/THUNDERSTORMS ACROSS PARTS
OF OUR AREA OVERNIGHT...ESPECIALLY UP NORTH DURING THE REST OF THE EVENING
HOURS...AS ACTIVITY HEADS OUR WAY. 42
&&
PREV DISCUSSION... /ISSUED 712 PM CDT WED APR 22 2015/
DISCUSSION...
00Z AVIATION DISCUSSION BELOW.
AVIATION...
THIS EVENING`S SUPERCELL THAT MOVED OFF THE UPPER TEXAS COAST AND
ACROSS SAN ANTONIO BAY APPEARS TO HAVE ROBBED INFLOW INTO THE
ONCE RAGGED SOUTHWESTERN FORECAST AREA`S CONVECTION THAT WAS
MOVING EAST AN HOUR AGO. ALL THAT IS LEFT IS A LIGHT RAIN SHIELD
CURRENTLY AFFECTING LBX...THIS LIGHT PRECIPITATION MOVING SOUTH
OF THE METRO TERMINALS. VFR DECKS THIS EVENING WILL LOWER BACK TO
MVFR JUST BEFORE SUNRISE. A LIGHT SOUTH BREEZE WITH CEILINGS
LIFTING BACK UP TO VFR BY LATE THURSDAY MORNING. UPPER RIDGING
FORMING JUST DOWNSTREAM OF NEXT BAJA REGION TROUGH SHOULD PROVIDE
ENOUGH SUBSIDENCE TO KEEP THURSDAY DRY. REGIONAL PROG SOUNDINGS
DEPICT A DRYING COLUMN...ESPECIALLY IN THE MID-LAYERS...AND NO
DISCERNIBLE APPROACHING UPSTREAM SHORTWAVE DISTURBANCE AID IN
LEANING THIS TAF PACKAGE TOWARDS A DRY BIAS. 31
&&
PREV DISCUSSION... /ISSUED 402 PM CDT WED APR 22 2015/
DISCUSSION...
UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY STILL SHOW A RATHER
PERSISTENT SOUTHERN JET STREAM OVER MUCH OF TX. IT IS HARD TO
IDENTIFY BUT IT APPEARS THAT THE CONVECTION OVER THE COASTAL BEND
AND NOW EAST OF SAN ANTONIO MAY BE SUPPORTED BY A WEAK SHORTWAVE
TROUGH. OVERALL PATTERN SHOWS WEAK SHORT WAVE RIDGING BUT THIS
DISTURBANCE MAY BE FLATTENING OUT THE RIDGE A BIT TODAY.
THERMODYNAMIC AND SHEAR PARAMETERS SUPPORT THE THREAT FOR SEVERE
STORMS WITH SOME STORMS BECOMING ORGANIZED. SHEAR WILL SUPPORT
STORM ROTATION AND LOW LEVEL TURNING OF THE WINDS WITH A
DEVELOPING WARM FRONT MAY BE ENOUGH TO SUPPORT LOW LEVEL ROTATION
IN STORMS ESPECIALLY ALONG THE COASTAL BEND. RECENT RAP/HRRR MODEL
RUNS BRING CONVECTION EAST OF KSAT INTO SE TX AROUND 23-01Z.
MODELS SHOW THAT STORMS MAY BE WEAKENING BUT COULD BE MOVING INTO
A MORE FAVORABLE ENVIRONMENT GIVEN TRENDS IN HEATING/INSTABILITY.
MODELS ALSO SHOW CONVECTION ALONG A BOUNDARY STRETCHING NW/SE FROM
MINERAL WELLS TO LUFKIN. THIS HIGHLIGHTS THE SEVERE THREAT FOR THE
NORTHERN MOST COUNTIES IN THE FORECAST AREA MAINLY
MADISON...HOUSTON...TRINITY CO. THE IDEA IS FOR THE THREAT TO END
LATER TONIGHT BUT HRRR TRENDS SHOW CONVECTION COMING DOWN FROM
THE METROPLEX AND AFFECT THE AREAS FROM COLLEGE STATION TO
HUNTSVILLE OVER THE LIVINGSTON BY EARLY MORNING HOURS. SO IT
APPEARS THERE WILL BE AT LEAST SOME OVERNIGHT THREAT.
THURSDAY LOOKS A BIT MORE QUIET AS MODELS DO AMPLIFY RIDGING OVER
THE REGION ALTHOUGH THERE WILL BE PLENTY OF MOISTURE/INSTABILITY
TO SUPPORT SEVERE STORMS. WE DO NOT WANT TO BE COMPLACENT BUT
THINK 20/30 POPS MIGHT BE GENEROUS. MOVING AHEAD TO
FRIDAY...RIDGING MOVES EAST IN RESPONSE TO UPPER LEVEL TROUGH OVER
THE S ROCKIES PUSHING INTO THE TX PANHANDLE AND S PLAINS. SFC LOW
DEEPENS AND MOVES INTO THE C PLAINS IN RESPONSE WITH STRONG JET
STREAK FROM MIDLAND TO OKC. THIS PUTS SE TX ON A MORE SUBSIDENT
SIDE OF THE JET BUT THAT MAY NOT MATTER MUCH WITH THE CURVATURE OF
THE JET. THERE IS ALSO A PACIFIC FRONT THAT DEVELOPS WITH
CONVECTION FORMING IN C TX MOVING EAST. THIS WILL AGAIN PUT AREAS
NORTH OF I-10 IN A THREAT FOR SEVERE WEATHER SINCE THERE WILL
AGAIN BE PLENTY OF MOISTURE/INSTABILITY AND SHEAR. MAIN QUESTION
WILL BE CAP STRENGTH. 850MB WINDS VEER TO SW WITH TEMPS AROUND 20C
OR MORE FOR MUCH OF THE SOUTHERN HALF OF THE AREA. AGAIN THIS
SUPPORTS IDEA OF AREAS NORTH OF I-10 OR EVEN NORTH OF CONROE WILL
HAVE A HIGHER THREAT FOR SEVERE WEATHER FRIDAY.
WE CONTINUE THUNDERSTORM CHANCES SATURDAY AS THE THROUGH PASSES NE
OF THE AREA OVERNIGHT. SOUTHERN JET STILL IS STRONG OVER THE
REGION. PACIFIC FRONT STALLS OVER THE AREA WHICH COULD SUPPORT A
FEW STORMS BUT WITH 850MB FLOW BECOMING MORE WSW...THINK STORMS
WILL BE ISO IN NATURE. WITH THE VEERED BOUNDARY LAYER FLOW...MAX
TEMPS COULD REACH UPPER 80S TO 90F BOTH SAT/SUN.
WHILE THERE MAY BE A BREAK FROM SEVERE WEATHER OVER THE
WEEKEND...MONDAY COULD BE ACTIVE AGAIN. BOTH GFS/ECMWF BRING A
UPPER LOW INTO THE PLAINS DURING THE DAY MON WITH FAVORABLE
SPLITTING JET STRUCTURE. LARGE SCALE ASCENT WILL BE STRONG ENOUGH
TO ERODE ANY CAPPING LEADING TO A MID MORNING TO EARLY AFTERNOON
SEVERE WEATHER CHANCES. DRYLINE/PACIFIC FRONT PUSHES THROUGH MON
NIGHT INTO TUE AS THUNDERSTORM ACTIVITY MOVES EAST. A STRONGER
COLD FRONT PUSHES THROUGH TUESDAY WHICH MUCH COLDER AIR BEHIND IT.
IN FACT THE 850MB TEMPS DROP TO ANYWHERE BETWEEN 4C AND 8C TUE
NIGHT INTO WED DEPENDING ON THE MODEL. SO IT LOOKS LIKE MONDAY
WILL NEED TO BE WATCHED CLOSELY FOR DETAILS ON SEVERE WEATHER BUT
GOOD NEWS THAT THERE COULD BE A STRONG COLD FRONT TO PUSH THROUGH
ONE LAST TIME BEFORE HEADING INTO THE MONTH OF MAY. 39
MARINE...
AS HIGH PRESSURE LINGERS TO THE EAST AND PRESSURES FALL OVER THE SRN
PLAINS...THE LIGHT/MODERATE ONSHORE FLOW WILL BE CONTINUING OVER THE
UPPER TX COAST THROUGH THE END OF THE WEEK/INTO THE WEEKEND. STRONG-
ER GUSTS/LIMITED VISIBILITIES POSSIBLE WITH STORMS DEVELOPING ACROSS
THE COASTAL WATERS THE REST OF THIS AFTN/EVENING...WITH LATER ROUNDS
OF PCPN POSSIBLE THURS AND FRI. LONG-RANGE MODELS STILL GOING WITH A
STRONG COLD FRONT INTO THE GULF WATERS NEXT TUES. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 85 71 83 68 / 30 30 30 60 20
HOUSTON (IAH) 69 86 73 84 71 / 20 20 20 40 20
GALVESTON (GLS) 72 82 73 82 73 / 20 20 20 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...31
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
938 PM CDT FRI APR 24 2015
.UPDATE...
RAIN SHOWERS DIMINISHING AS FORCING FROM 700 MB WARM ADVECTION AND
A WEAK VORTICITY MAXIMUM SHIFT EAST/NORTHEAST. HAD SOME BRIEF
PERIODS OF GRAUPEL...AND EVEN SNOW AS THE DENDRITE GROWTH ZONE
MOISTENED AND THE COLUMN COOLED TO 0C ALMOST DOWN TO THE
SURFACE...MIXED IN WITH THE MORE-DEEPLY CONVECTIVE SHOWERS
EARLIER.
LOOKS TO BE RELATIVELY QUIET FOR THE OVERNIGHT WITH A DRY
EASTERLY LOW-LEVEL FLOW...WITH ONLY SOME ISOLATED LIGHT
SHOWERS/SPRINKLES. BETTER CHANCES FOR SHOWERS LOOK TO STAY SOUTH
OVERNIGHT ACROSS NRN IL ALONG AND JUST TO THE NORTH OF THE
SURFACE BAROCLINIC ZONE PER THE LATEST HRRR AND RAP 13 MODEL
DEPICTIONS. NEW NAM 12 IS NOT BRINGING MEASURABLE RAIN INTO
SOUTHERN WISCONSIN SATURDAY...CONTINUING A TREND IN EARLIER MODEL
RUNS THAT WERE HINTING AT A SOUTHERLY SHIFT TO THE PRECIPITATION
SHIELD.
&&
.AVIATION/06Z TAFS/...
LOOKING FOR RELATIVELY DRY...VFR CONDITIONS INTO THE EARLY OVERNIGHT
WITH ONLY A PASSING SPRINKLE OR ISOLATED LIGHT RAIN SHOWER.
LOOKING FOR CIGS TO LOWER TO MVFR LEVELS AROUND 09Z AT KMSN...AND
BETWEEN 12Z AND 13Z AT EASTERN SITES WITH MOISTURE ADVECTING INTO
SOUTHERN WISCONSIN AHEAD OF APPROACHING LOW PRESSURE. NEW NAM 12
IS NOT BRINGING MEASURABLE RAIN INTO SOUTHERN WISCONSIN
SATURDAY...CONTINUING A TREND IN EARLIER MODEL RUNS THAT WERE
HINTING AT A SOUTHERLY SHIFT TO THE PRECIPITATION SHIELD. WILL
LOOK AT MORE OF THE 00Z DATA SET COMING IN PRIOR TO ISSUANCE TO
SEE IF VSBY REDUCING PCPN WILL OCCUR...THOUGH EXPECT AT LEAST MVFR
CIGS IF NOT LOWER. EAST WINDS WILL BE INCREASING IN THE EARLY TO
MID MORNING HOURS WITH GUSTS OF 20 TO 25 KNOTS.
&&
.MARINE...A SMALL CRAFT ADVISORY GOES INTO EFFECT AT 7 AM CDT
SATURDAY AS EAST WINDS WILL STEADILY INCREASE OVERNIGHT...REACHING
SMALL CRAFT ADVISORY LEVELS EARLY SATURDAY MORNING...THEN BECOMING
NORTHEAST BY SATURDAY NIGHT. GUSTS TO 25 KNOTS ARE EXPECTED
SATURDAY INTO SATURDAY EVENING...WITH A TIGHT PRESSURE GRADIENT
MOVING ACROSS THE WATERS OF SOUTHERN LAKE MICHIGAN FROM PASSING
LOW PRESSURE TO THE SOUTH.
ONSHORE FLOW WILL BUILD WAVE HEIGHTS INTO THE 2 TO 4 FOOT RANGE
BY MORNING...AND 3 TO 6 FEET BY LATE IN THE AFTERNOON AND EARLY
EVENING WITH THE LONGER NORTHEAST FETCH. WINDS DIMINISH FOR A
TIME LATE SATURDAY NIGHT...WITH WAVES DIMINISHING A BIT TOWARDS
MORNING. LATEST NAM HAS A NORTH FETCH SUNDAY...WHICH MAY KEEP
HIGHER WAVES JUST OFFSHORE. NEXT SHIFT WILL HAVE TO ASSESS NEED TO
EXTEND ADVISORY BEYOND SUNDAY MORNING EXPIRATION.
&&
.PREV DISCUSSION... /ISSUED 342 PM CDT FRI APR 24 2015/
TONIGHT AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
AREA OF RAIN SHOWERS EXTENDS FROM NORTH CENTRAL IOWA AND SOUTHEAST
MINNESOTA INTO SOUTH CENTRAL WISCONSIN. THIS IS IN RESPONSE TO 700
MB WARM AIR ADVECTION AND FRONTOGENESIS RESPONSE...AS WELL AS FROM
AN ADVANCING 500 MB VORTICITY MAXIMUM. THESE FEATURES SHOULD
CONTINUE TO SLIDE EAST NORTHEAST ACROSS THE AREA INTO EARLY THIS
EVENING...SPREADING LIGHT TO MODERATE RAIN SHOWERS THROUGH THE AREA.
STRENGTH OF UPWARD VERTICAL MOTION SHOULD OVERCOME DRY LOW LEVELS
BELOW 5000 FEET ABOVE GROUND LEVEL DURING THIS TIME. RAP SOUNDINGS
SHOWING WEAK ELEVATED CAPE...LITTLE TO NONE ON OTHER MODELS...SO
WILL NOT INCLUDE THUNDER MENTION.
500 MB SHORTWAVE TROUGH SLIDES EAST SOUTHEAST FROM NORTHWEST
MISSOURI TO CENTRAL ILLINOIS SATURDAY. MODELS HAVE BEEN TRENDING
SLIGHTLY SOUTHWARD WITH THE BEST UPWARD VERTICAL MOTION ASSOCIATED
WITH THE SHORTWAVE AND LOW TO MID LEVEL FRONTOGENESIS/Q VECTOR
CONVERGENCE. THUS...THE QPF SHIELD IN THE MODELS HAS TRENDED A BIT
SOUTHWARD AS WELL.
AREA FORECAST SOUNDINGS STILL SHOWING A FAIR AMOUNT OF DEEP MOISTURE
IN THE SOUTH LATER TONIGHT INTO SATURDAY...LESS SO IN THE FAR
NORTHERN COUNTIES. LOOKS TO BE A NORTH TO SOUTH GRADIENT IN THE POPS
FOR THIS SYSTEM...WITH SOME UNCERTAINTY WITH THE SYSTEM TRACK.
CONTINUED HIGH POPS IN THE SOUTHERN 2/3 OF THE AREA SATURDAY...WITH
CHANCE POPS IN THE FAR NORTH. EAST NORTHEAST WINDS ARE EXPECTED TO
GRADUALLY INCREASE IN MAGNITUDE TONIGHT...WITH GUSTY EAST NORTHEAST
WINDS SATURDAY. THIS WILL MAKE FOR A RAW DAY WITH THE RAIN. LOWS
TONIGHT WILL DROP INTO THE UPPER 30S TO AROUND 40...WITH HIGHS ONLY
IN THE 40S SATURDAY WITH THE CLOUDS AND RAIN.
SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE HIGH.
ANY LINGERING PRECIPITATION WILL COME TO AN END SATURDAY EVENING AS
A SHORTWAVE IMPULSE AND ASSOCIATED SFC LOW TRACK EASTWARD THROUGH
THE OHIO VALLEY. UPSTREAM 500 MB HEIGHTS BEGIN RISING OVER MINNESOTA
ON SATURDAY NIGHT...WITH THE MID-LEVEL RIDGE AXIS BECOMING ORIENTED
FROM THE CENTRAL PLAINS NORTHEASTWARD INTO SOUTHERN ONTARIO BY
MONDAY. THIS WILL SUPPORT SFC RIDGING THAT BUILDS INTO THE WESTERN
GREAT LAKES AND UPPER MIDWEST REGIONS ON SUNDAY NIGHT INTO MONDAY.
LOW-LEVEL COLD ADVECTION AND NORTHEASTERLY FLOW OFF THE LAKE WILL
KEEP TEMPERATURES RELATIVELY COOL ON SUNDAY. 925 MB TEMPERATURES IN
THE 3 TO 8C RANGE SUPPORT HIGHS IN THE 50S TO NEAR 60 AWAY FROM THE
LAKESHORE. WITH NEAR NEUTRAL LOW-LEVEL THERMAL ADVECTION AND
NORTHERLY FLOW ON MONDAY EXPECT READINGS TO WARM A BIT MORE ACROSS
THE WEST. PERSISTENT EASTERLY WIND COMPONENT WILL ONCE AGAIN PREVAIL
FOR THE EASTERN CWA ON MONDAY...KEEPING THE LAKESHORE COMMUNITIES
COOLER.
TUESDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM.
MID-LEVEL RIDGING INITIALLY OVER THE EASTERN GREAT LAKES REGION
SHIFTS EAST INTO NEW ENGLAND THROUGH WEDNESDAY AS SHORTWAVE ENERGY
ADVANCES FROM THE NORTHERN/CENTRAL PLAINS INTO THE EASTERN GREAT
LAKES AND MISSISSIPPI VALLEY REGIONS. SOME UNCERTAINTY REGARDING
SHORTWAVE EVOLUTION TUESDAY NIGHT...WITH DETERMINISTIC 00Z ECMWF
BRINGING A MORE PROGRESSIVE AND STRONGER WAVE THROUGH SOUTHERN
WISCONSIN THAN THE 06Z GFS. 12Z ECMWF RUN APPEARS SLOWER...AND
EVOLVES A CLOSED LOW OVER LAKE MICHIGAN ON WEDNESDAY. SOME LIGHT
PCPN IS POSSIBLE TUESDAY NIGHT OR WEDNESDAY...BUT OVERALL FORCING
FOR ASCENT APPEARS WEAK. WARMING 925 MB TEMPERATURES OF 9-12C
SUPPORT HIGHS POTENTIALLY REACHING WELL INTO THE 60S AWAY FROM THE
LAKE.
THURSDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
MID-LEVEL RIDGE AXIS SETS UP OVER THE NORTHERN PLAINS WITH WEAK SFC
RIDGING KEEPING THINGS QUIET ACROSS THE CWA FOR THURSDAY INTO FRIDAY
AFTERNOON. THEREAFTER...MODEL DIFFERENCES IN THE TIMING/STRENGTH OF
A SHORTWAVE IMPULSE PASSING THROUGH SOUTHERN CANADA SUGGEST ADDING
SLIGHT CHANCE POPS FOR AREA FRIDAY NIGHT. SOME UNCERTAINTY REGARDING
TEMPERATURES DURING THE PERIOD...AND DID NOT DEVIATE FROM MODEL
BLENDED CONSENSUS VALUES.
AVIATION/00Z TAFS/...
LIGHT TO MODERATE BAND OF RAIN SHOWERS SHOULD
CONTINUE TO MOVE EAST NORTHEAST THROUGH THE AREA THROUGH EARLY THIS
EVENING. VFR CONDITIONS SHOULD REMAIN DURING THIS TIME.
EAST/SOUTHEAST WINDS WILL BECOME EAST NORTHEAST BY MIDDLE TO LATE
EVENING...GRADUALLY INCREASING IN STRENGTH LATER TONIGHT.
A LULL IN THE SHOWER ACTIVITY SHOULD OCCUR LATER THIS EVENING AND
INTO THE OVERNIGHT HOURS...UNTIL MAIN TROUGH OF LOW PRESSURE SLIDES
EAST SOUTHEAST FROM NORTHWEST MISSOURI INTO CENTRAL ILLINOIS
SATURDAY.
AREA OF LIGHT TO MODERATE RAIN SHOULD SPREAD ACROSS TAF SITES
BETWEEN 10Z AND 14Z SATURDAY...LINGERING THROUGH THE DAY. EAST TO
EAST NORTHEAST WINDS WILL REMAIN MODERATE IN STRENGTH
SATURDAY...WITH GUSTS TO AROUND 24 KNOTS. EXPECT MAINLY MVFR
CEILINGS AND VISIBILITIES WITH THE RAIN. SOME IFR VISIBILITIES AND
CEILINGS ARE POSSIBLE TOWARD KENOSHA...REMAINING ABOVE ALTERNATE
MINIMUMS.
MARINE...
EAST NORTHEAST WINDS ARE EXPECTED TO GATHER STRENGTH TONIGHT INTO
SATURDAY...BECOMING NORTHEAST SATURDAY NIGHT. GUSTS TO 25 KNOTS ARE
EXPECTED SATURDAY INTO SATURDAY NIGHT...WITH TIGHT PRESSURE GRADIENT
FROM PASSING LOW PRESSURE TO THE SOUTH.
ONSHORE FLOW WILL BUILD WAVE HEIGHTS INTO THE 3 TO 6 FOOT RANGE FOR
THE NEARSHORE WATERS. A SMALL CRAFT ADVISORY WILL BE NEEDED FOR
SATURDAY AND SATURDAY NIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 7 AM CDT SUNDAY FOR
LMZ645-646.
SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 7 AM CDT SUNDAY FOR
LMZ643-644.
&&
$$
UPDATE...REM
TONIGHT/SATURDAY AND AVIATION/MARINE...WOOD
SATURDAY NIGHT THROUGH FRIDAY...SPM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT WED APR 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER BRITISH COLUMBIA...ALONG THE SOUTHERN
CALIFORNIA COAST...AND OVER THE FORECAST AREA INTO THE GREAT
LAKES...WHILE RIDGING EXTENDED FROM THE FOUR CORNERS OF THE U.S.
INTO ALBERTA. CYCLONIC FLOW OF MOISTURE AROUND THE GREAT LAKES UPPER
TROUGH...NICELY SEEN ON THE 12Z GRB SOUNDING...HELPING TO HOLD
STRATOCUMULUS ACROSS WI. GO A LITTLE MORE TO THE WEST OVER MN AND
IA...MUCH DRIER AIR WAS PRESENT ON THE 12Z MPX SOUNDING WITH A
PRECIPITABLE WATER OF 0.16 INCHES OR 36 PERCENT OF NORMAL. THIS
DRIER AIR HAS RESULTED IN CLEARER SKIES. A RIDGE OF HIGH PRESSURE
ACCOMPANYING THE CLEAR SKIES WAS LOCATED OVER THE EASTERN DAKOTAS. A
TIGHT PRESSURE GRADIENT EAST OF THIS RIDGE MAINTAINING A BRISK
NORTHWEST BREEZE OVER THE FORECAST AREA WITH SPEEDS/GUSTS A LITTLE
LOWER THAN 24 HRS AGO. STILL...THE SPEEDS HAVE BEEN STRONG ENOUGH TO
WARRANT THE EARLIER ISSUED WIND ADVISORY FOR A SMALL PORTION OF
NORTHEAST IOWA. AIRMASS REMAINS UNSEASONABLY COOL WITH 850MB TEMPS
IN THE -5 TO -8C RANGE...RESULTING IN THE PRESENT 40S
TEMPERATURES...AND EVEN 30S AT MEDFORD WI.
THE UPPER TROUGH AFFECTING THE FORECAST AREA INTO THE GREAT LAKES IS
PROGGED TO MAKE MUCH MORE EASTWARD PROGRESS OVER THE NEXT 24
HOURS...REACHING NEW ENGLAND BY 00Z FRI. THIS WILL ALLOW THE RIDGING
AND WARMER/DRIER AIR OVER THE NORTHERN ROCKIES AND PLAINS TO MARCH
TOWARDS THE FORECAST AREA. WE DO HAVE ONE SHORTWAVE TO CONTEND WITH
COMING DOWN THE BACK SIDE OF THE UPPER TROUGH TONIGHT...WHICH ITS
MAIN IMPACT IS TO BRING IN SLIGHTLY COOLER AIR FOR 12Z THU BEFORE
THE WARMING COMMENCES.
CLOUDS MAY BE A BIT PERSISTENT NORTHEAST OF I-94 TONIGHT...THANKS TO
THAT SHORTWAVE COMING THROUGH...BUT ELSEWHERE ANY STRATOCUMULUS WILL
DISSIPATE WITH LOSS OF DAYTIME HEATING. THIS CLEARING COMBINED WITH
WINDS DIMINISHING SOME AS THE RIDGE APPROACHES I-35 BY 12Z THU IS
EXPECTED TO RESULT IN A CHILLY NIGHT. 20S SHOULD BE COMMON ACROSS
MUCH OF THE REGION BY SUNRISE WITH PERHAPS NEAR 30 READINGS IN THE
MS RIVER VALLEY. NO FROST/FREEZE HEADLINES WILL BE POSTED YET AS
VEGETATION GROWTH IS NOT QUITE THERE. 850MB TEMPS ON THU CLIMB TO 0
TO -2C BY 00Z FRI WHICH WITH PLENTY OF SUN SHOULD BE ABLE TO BOOST
TEMPERATURES INTO THE LOW TO MID 50S FOR MOST LOCATIONS. MEDFORD
AGAIN MIGHT BE THE LONE COOLER EXCEPTION BEING CLOSER TO THE
DEPARTING COLD AIR. DEEP MIXING IS LIKELY AS WELL IN THE DRY AIRMASS
FEATURING PRECIPITABLE WATER NEAR 0.10 INCHES...CAUSING LOW RELATIVE
HUMIDITY VALUES. THE COMBINATION OF THESE LOW VALUES AND A 10 TO 15
MPH NORTHWEST BREEZE COULD RESULT IN SOME FIRE WEATHER CONCERN. SEE
FIRE WEATHER SECTION BELOW FOR MORE DETAILS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 243 PM CDT WED APR 22 2015
FIRST FOCUS OF THE LONG TERM PERIOD IS ON THE UPPER TROUGH NEAR THE
SOUTHERN CALIFORNIA COAST. MODELS ARE IN GOOD AGREEMENT LIFTING THIS
TROUGH INTO THE CENTRAL PLAINS ON FRIDAY AND INTO CENTRAL ILLINOIS
ON SATURDAY. ALTHOUGH THIS TRACK IS SOUTH OF THE FORECAST AREA...WE
STILL HAVE SOME SHOT AT PRECIPITATION DURING THE FRIDAY-SATURDAY
TIME FRAME. PART OF THIS IS DUE TO A SOMEWHAT DECENT MOISTURE SURGE
AHEAD OF THE TROUGH UP INTO THE FORECAST AREA ON FRIDAY...REFLECTED
BY PRECIPITABLE WATER CLIMBING TO AROUND 0.75 INCHES BY 00Z SAT.
ADDITIONALLY...A SHORTWAVE IS PROGGED TO EJECT OUT OF THE TROUGH AND
MOVE THROUGH THE AREA ON FRIDAY...INTERACTING WITH THE MOISTURE.
THEREFORE...CHANCES OF PRECIPITATION PERSIST FOR FRIDAY...ESPECIALLY
IN THE AFTERNOON AND INTO THE NIGHT WEST OF THE MS RIVER WHERE MORE
MOISTURE EXISTS. PRECIPITATION SHOULD BEGIN TO WANE NORTH TO SOUTH
ON SATURDAY AS THE UPPER TROUGH MOVES EAST OF OUR LONGITUDE...
CUTTING OFF THE MOISTURE TRANSPORT AND ALLOWING DRIER AIR TO GET
DRAWN IN FROM THE NORTH AND EAST. SOME MODEL DIFFERENCES EXIST ON
HOW MUCH PRECIPITATION EXISTS ON SATURDAY DUE TO SLIGHT NORTH/SOUTH
DIFFERENCES OF THE UPPER TROUGH TRACK...WITH THE 22.12Z GFS/CANADIAN
FARTHEST NORTH UP TO US-10 AND 22.12Z NAM/ECMWF FARTHEST SOUTH TO
AROUND US-20. THEREFORE...PRECIPITATION CHANCES ON SATURDAY REMAIN
AT OR BELOW 50 PERCENT. BETWEEN THE CLOUDS AND PRECIPITATION...HIGH
TEMPERATURES LOOK TO BE A LITTLE COOLER THAN ON THU.
A DRIER AND WARMER PERIOD IS ON TAP FOR SUNDAY AS AN UPPER RIDGE
AXIS APPROACHES THE FORECAST AREA FROM THE WEST. WITH 850MB TEMPS OF
0-2C...SHOULD SEE HIGHS CLIMB WELL UP INTO THE 50S AND POSSIBLY 60S
IN RIVER VALLEYS. EASTERLY FLOW FROM HIGH PRESSURE OVER ONTARIO
LIKELY TO CAUSE RELATIVE HUMIDITIES TO TANK.
MODELS HAVE CHANGED THEIR TUNE A BIT FOR SUNDAY NIGHT THROUGH MONDAY
NIGHT...LEANING TOWARDS DRIER AND WARMER. THIS IS A RESULT OF A
SHORTWAVE TROUGH COMING INTO THE PACIFIC NORTHWEST ON SATURDAY
THAT...INSTEAD OF HEADING TOWARDS THE FORECAST AREA...NOW DIGS DOWN
INTO THE SOUTHERN PLAINS. THEREFORE HAVE FOLLOWED SUIT...DRYING OUT
THE FORECAST AND RAISING TEMPERATURES.
AS WE HEAD INTO TUESDAY AND WEDNESDAY...UPPER RIDGING IS PROGGED TO
DEVELOP OVER THE WESTERN U.S. INTO WESTERN CANADA...CAUSING
SHORTWAVES TO DROP INTO THE REGION ON NORTHERLY FLOW. AS A
RESULT...SOME LOW PRECIPITATION CHANCES ARE IN THE FORECAST. HARD TO
SAY HOW MUCH PRECIPITATION WILL FALL GIVEN LACK OF MOISTURE
AVAILABILITY. DESPITE THE NORTHERLY FLOW...850MB TEMPS ARE STILL
PROGGED IN THE 2-4C RANGE SO TEMPERATURES DO NOT LOOKS TO CHANGE
MUCH FROM MONDAY AND STAY JUST BELOW SEASONABLE NORMALS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1147 PM CDT WED APR 22 2015
SKIES WILL REMAIN MAINLY CLEAR THROUGH THE PERIOD. NORTHWEST WINDS
WILL REMAIN LESS THAN 10 KNOTS THROUGH 24.03Z...AND THEN BECOME
LIGHT SOUTHEAST.
&&
.FIRE WEATHER...
ISSUED AT 243 PM CDT WED APR 22 2015
TODAY HAS BEEN MOSTLY A DRYING DAY WEST OF THE MISSISSIPPI RIVER
WHERE MORE SUN HAS OCCURRED...CLOSER TO THE DRIER AIR OVER WESTERN
MN AND WINDS HAVE BEEN GUSTING 30-40 MPH. A WARMER DAY IS EXPECTED
ACROSS THE REGION ON THURSDAY WITH SUNNY SKIES. ADDITIONALLY...THE
DRY AIR OVER WESTERN MN MOVES IN...PLUMMETING RH VALUES TO 20-30
PERCENT. HOWEVER...WINDS DO NOT LOOK NEARLY AS STRONG WITH HIGH
PRESSURE MOVING IN...ONLY IN THE 10 TO 15 MPH RANGE. WITH SOME
GREEN-UP ALREADY OCCURRING AND THE LIGHTER WINDS...HAVE DECLINED
TO CONSIDER ANY FIRE WEATHER HAZARDS AT THIS TIME. SOME RAIN
REMAINS ON TAP TO MOVE INTO THE REGION FOR FRIDAY...ALONG WITH
CLOUDS...WHICH BOTH SHOULD HELP MITIGATE FIRE WEATHER CONCERNS.
LOOKING AHEAD...SUNDAY COULD BE ANOTHER DAY WORTH WATCH FOR FIRE
WEATHER CONCERNS...BUT SIMILAR TO THURSDAY WINDS ARE EXPECTED ON
THE LIGHTER SIDE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1015 PM PDT Fri Apr 24 2015
.Synopsis...
A fast moving wet system pushes across the area tonight and
Saturday morning bringing at least light precipitation most areas.
High pressure brings dry conditions Sunday through mid week next week.
Warmest temperatures Monday with slight cooling trend through the
end of the week.
&&
.Discussion...
Precipitation has moved in a few hours early and updated forecast
to increase overnight rain chances and amounts. Short term model
indicate the heaviest rates between 11pm-4am. Snow is falling above
6000 feet and should begin accumulating on roadways during the
next few hours. Snow rates up to 2 inches per hour will be
possible in the 11pm-5am...hazard travel and chain control will be
likely after 11pm. Valley rain amounts will vary widely given
shadow effects with 0.50-1.00 inches southern valley and less than
0.10 northern valley. HRRR ends valley precip by 5am and current
precip may be over done if this model is correct.
.Previous Discussion...
Cooler this afternoon than yesterday with more cloud cover and
stronger onshore flow along with a cooler airmass. Temperatures
this afternoon are running in the upper 60s to low 70s in the
Valley and mid 30s to low 50s in the mountains, which are near
normal for this time of year. Temperatures will generally be a
little cooler tomorrow after behind the cold front that passes
through earlier in the day.
A cold and wet system will move in tonight (mainly after sunset) into
Saturday bringing widespread precipitation and lower snow levels.
Increased precipitation amounts some from previous forecast,
especially around I-80 and south. Precipitation is expected to
become more showery during the day Saturday. Showers may linger
over the Sierra into Saturday evening. Snow levels are expected to drop
to around 5500 ft around midnight tonight. Snow accumulations of several
inches are expected over the passes with around a foot possible
over the Sierra peaks. Snow may cause travel delays over the
Sierra with slick roads and reduced visibilities. The heaviest
snow is expected around midnight to around sunrise. Rainfall amounts are
generally expected to be a tenth to around a third of an inch in
the Valley and Coastal Range, and around half to 0.75 inches in
Sierra foothills and around an inch in the Sierra. Afternoon
temperatures on Saturday are expected to reach the upper 60s to
low 70s in the Valley and mid 30s to low 50s in the mountains.
These temperatures are generally a few degrees below normal for
this time of year. Temperatures warm up Sunday afternoon by around
10 degrees compared to Saturday as high pressure builds into the
area along with Northerly winds. Sunday afternoon highs are
expected to be in the upper 70s to low 80s in the Valley and upper
40s to upper 60s in the mountains which is generally a few degrees
above normal for this time of year. Sunday and Monday should be
dry with high pressure over the area.
.Extended Discussion (Tuesday through Friday)
High amplitude omega ridge shifts east through the Great Basin
Tuesday into Wednesday as a Pacific storm moves through the PacNW.
Result will be increasing onshore flow with minor synoptic cooling
trend. Main dynamics and moisture remain focused north of the
forecast area for dry weather Tue/Wed. Another system is progged
through Thursday with the GFS/GEM digging it deeper across NorCal
than the EC. With ridge axis well east over the middle of the U.S.,
leaning towards the deeper solutions and ADJMRA. Have introduced
threat of showers and thunderstorms mainly over the Shasta
mountains Thursday afternoon into evening. Greater cooling
expected Thursday with highs in the Central Valley forecast in the
mid 70s to around 80. Models differ from broad troughing aloft to
weak upper ridging Friday but all suggest drier weather with a
slight increase in max temps.
&&
.Aviation...
Dtrtg conds tngt as Pac stm movs inld. Areas MVFR in pcpn poss in
Cntrl Vly btwn 05z-17z Sat. Omtns aft 05z, wdsprd MVFR/IFR poss with
lcl LIFR in pcpn thru abt midday Sat then lcl MVFR/IFR poss in
shwrs til 04z Sun. Sn lvls lwrg to arnd 050 to 055 amsl by Sat
mrng. SW-Wly sfc wnd gsts up to 30 kts poss thru Delta and ovr hyr
mtn trrn tngt.
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 5 pm pdt saturday above 5500 feet
in the west slope northern sierra nevada...western plumas
county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1006 PM MDT FRI APR 24 2015
.UPDATE...
ISSUED AT 1000 PM MDT FRI APR 24 2015
THE SHORTWAVE RIDGE AXIS OVER FAR WESTERN COLORADO THIS EVENING
HAS DIMINISHED BUT NOT ELIMINATED SHOWERS. THE RIDGE WILL SHIFT
EAST OF THE FORECAST AREA BY MORNING. MOISTURE IS WORKING IN FROM
THE WEST BEHIND THE RIDGE WITH PRECIPITABLE WATER VALUES STILL
PROGGED TO BE MORE THAN 0.5 INCH ACROSS THE REGION. A STRONG VORT
MAX THAT WAS MOVING INTO NW UTAH WILL BRING A BAND OF SHOWERS AND
PERHAPS ISOLATED THUNDERSTORMS INTO NE UTAH BEFORE SUNRISE. THE
REMAINDER OF THE FORECAST AREA WILL SEE THIS STRONGER FORCING
INCREASING THROUGH THE MORNING HOURS.
SNOW LEVELS GENERALLY REMAIN HIGH THROUGH SATURDAY. WET BULB ZERO
LEVELS ARE AROUND 9-10KFT THROUGH SATURDAY THOUGH CONVECTION WILL
DRIVE SNOW BRIEFLY DOWN ANOTHER 1K TO 2KFT. MODELS CONTINUE TO
PRODUCE SIGNIFICANT SNOWFALL ACROSS THE REGION SATURDAY INTO
MONDAY THAT APPEARS TO BE OVERDONE ESPECIALLY FOR ELEVATIONS BELOW
10KFT. WE WILL EVALUATE FURTHER OVERNIGHT.
&&
UPDATE ISSUED AT 722 PM MDT FRI APR 24 2015
MINOR POP ADJUSTMENTS TO GRIDS AS SHOWERS HAVE BEEN MORE ISOLATED
IN NATURE SO FAR THIS EVENING. HRRR HINTING AT AN INCREASE IN
COVERAGE LATE TONIGHT INTO THE EARLY MORNING HOURS...FAVORING
EAST CENTRAL UTAH AS THE NEXT WAVE APPROACHES. ADDITIONAL UPDATES
LIKELY AS THE NIGHT PROGRESSES.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 359 PM MDT FRI APR 24 2015
NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE LATE
AFTERNOON AS H5 DIFLUENCE KEEPS MOST OF THE ACTIVITY OVER THE
MOUNTAIN TERRAIN OF WESTERN COLORADO. ISOLATED SHOWERS AND A
STRIKE OR TWO OF LIGHTNING CANNOT BE RULED OUT IN EASTERN UTAH AS
WELL...BUT DRIER AIR IS CURRENTLY SEEN ON SATELLITE IN EASTERN
UTAH SO ANYTHING THAT DEVELOPS THIS EVENING THERE WILL BE MAINLY
GUSTY WINDS. THIS SMALL `BREAK` OF DRIER AIR WILL SHIFT INTO
WESTERN COLORADO TONIGHT...SO ACTIVITY IS EXPECTED TO DECREASE
AROUND SUNSET UNTIL JUST BEFORE MIDNIGHT. SHORT TERM MODELS
INDICATE RAIN MOVING INTO SW COLORADO BY 10 OR 11 PM TONIGHT AND
NE UTAH JUST AFTER MIDNIGHT.
CLOUDY AND SHOWERY DAY ON TAP FOR SATURDAY AS A LEAD UPPER TROUGH
MOVES ACROSS NW CO IN THE MORNING. MODELS ARE CONSISTENT WITH A NERN
PACIFIC JET DIGGING THE MAIN BUT SPLITTING TROUGH SOUTH THROUGH THE
GREAT BASIN ON SATURDAY AND EVENTUALLY FORMING A CLOSED LOW OVER
ERN AZ BY MIDDAY SUNDAY. THIS LOW THEN TRACKS ACROSS CENTRAL NM
SUNDAY AFTERNOON/NIGHT. SHOULD SEE PRECIPITATION RAMP UP AGAIN
LATER SAT NIGHT AND SUNDAY MORNING AS THE 700 MB TROUGH AND COLD
FRONT COME THROUGH WITH PRECIPITABLE WATER VALUES OF 0.5 TO 0.7
INCH. FLOW SWITCHES FAIRLY QUICKLY TO EASTERLY SUNDAY AFTERNOON.
NAM AND TO SOME EXTENT THE GFS TRY TO BRIEFLY WRAP SOME DRIER AIR
BACK IN MIDDAY SUNDAY ON THE 305K ISENTROPIC SURFACE (ROUGHLY
700-600 MB) BUT THEN QUICKLY FILLS IT IN AS THE EASTERLY FLOW
PUSHES MOISTURE OVER THE DIVIDE. TEMPS ALOFT NOT OVERLY COLD
HOWEVER...SO SNOW LEVELS SHOULD REMAIN FAIRLY HIGH OUTSIDE OF THE
STRONGER CONVECTIVE SHOWERS/T-STORMS THAT COULD DRIVE IT BELOW
8000 FT AT TIMES. CONFIDENCE NOT HIGH ENOUGH TO ISSUE ANY WINTER
HIGHLIGHTS HOWEVER...BUT THE POSSIBILITY EXISTS WITH MODELS
PUTTING OUT 6+ INCHES BY SUNDAY EVENING OVER THE SAN JUANS AND ELK
MTNS. WILL CONTINUE WITH A SPECIAL WEATHER STATEMENT.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 359 PM MDT FRI APR 24 2015
THE UPPER LOW MOVES INTO THE SOUTHERN PLAINS MONDAY WITH DRIER
AIR PUSHING ACROSS ERN UT INTO WRN CO. SCATTERED SHOWERS WILL
LIKELY PERSIST MAINLY ALONG THE DIVIDE WITH DAYTIME HEATING
WORKING ON THE COOLER AIR. UPPER RIDGE BUILDS OVERHEAD BY MIDWEEK
FOR A DRYING AND WARMING TREND. AFTERNOON TEMPS WILL RISE ABOVE
NORMAL. MAY SEE A CHANCE OF SHOWERS LATE IN THE WEEK AS MODELS
BRING A PACIFIC TROUGH INLAND AND ACROSS THE NORTHERN ROCKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 1000 PM MDT FRI APR 24 2015
ONLY ISOLATED MAINLY MOUNTAIN SHOWERS EXPECTED THROUGH 09Z. THEN A
BROADER AREA OF SHRA/SHSN AND LOW CIGS/VSBY TO IMPACT NE UTAH
FIRST. BETWEEN 12-15Z THIS BAND OF SHOWERS WILL MOVE THROUGH
THE REMINDER OF EASTERN UTAH AND THROUGH WESTERN COLORADO BETWEEN
12Z-18Z. EXPECT WIDESPREAD -SHRA/-SHSN WITH SCT THUNDERSTORMS WITH
THIS BAND...WITH CIGS BLO 050 AND VIS BLO 3SM AT TIMES IN THE
HEAVIEST SHOWERS. MTN TOPS WILL BE OBSCD AT TIMES IN SHSN. SNOW
LEVEL AROUND 10000FT EXCEPT DOWN TO 8000FT IN HEAVIEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JOE
SHORT TERM...JAM/JAD
LONG TERM...JAD
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
500 AM EDT SAT APR 25 2015
...STRONG TO SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON
THROUGHOUT SOUTHEAST GA AND ALONG I-10 CORRIDOR...
.CURRENTLY...
EARLY MORNING SURFACE ANALYSIS DEPICTS HIGH PRESSURE (1018
MILLIBARS) PUSHING OFF THE SOUTHEAST U.S. COAST. WARM
FRONTOGENESIS IS OCCURRING OVER THE FLORIDA BIG BEND REGION AHEAD
OF STRENGTHENING LOW PRESSURE (995 MILLIBARS) OVER THE PLAINS
STATES. ALOFT...STOUT DEEP-LAYERED RIDGING REMAINS IN PLACE OVER
THE NORTHWESTERN CARIBBEAN...CREATING STRONG WEST/NORTHWEST FLOW
ALOFT LOCALLY ABOVE 700 MILLIBARS (10000 FEET). MEANWHILE...A
POTENT AND SLOW MOVING TROUGH IS SPINNING OVER THE PLAINS
STATES. A MESOSCALE CONVECTIVE SYSTEM (MCS) IS MOVING ACROSS THE
TENNESSEE VALLEY AND THE LOWER MISSISSIPPI RIVER VALLEY. PERIODS
OF HIGH CLOUDS CONTINUE TO STREAM OVER OUR REGION WITHIN THE
STRONG W/NW FLOW ALOFT. A LIGHT SOUTHEAST TO SOUTHERLY WIND FLOW
IS GENERALLY KEEPING TEMPERATURES IN THE 60S...EXCEPT NEAR 70 AT
THE COAST.
.NEAR TERM (TODAY AND TONIGHT)...
OUR LOCAL PRESSURE GRADIENT CONTINUES TO TIGHTEN...WITH BREEZY
SOUTH TO SOUTHWEST WINDS EXPECTED TO DEVELOP BY THE MID TO LATE
MORNING HOURS. A FEW SHOWERS WILL BE POSSIBLE OVER INLAND
SOUTHEAST GA AND THE SUWANNEE VALLEY THIS MORNING AS A WARM FRONT
LIFTS THROUGH OUR REGION. NOT BUYING INTO HRRR DEPICTION OF
DECAYING CONVECTION MIGRATING ACROSS OUR REGION EARLY THIS
AFTERNOON...AND PREFER THE ARW SOLUTION WHICH INDICATES THAT
CONVECTION WILL PRESS E/SE ACROSS THE OCMULGEE/ALTAMAHA RIVERS
EARLY THIS AFTERNOON AS SHORTWAVE ENERGY GLIDES INTO SOUTHEAST GA.
ATLANTIC SEA BREEZE WILL BE PINNED AND MAY HAVE A TOUGH TIME
MOVING INLAND AT ALL GIVEN TIGHT GRADIENT IN PLACE. ARW DEPICTS
CONVECTION BECOMING ORIENTED W/E TOWARDS SUNSET ALONG THE FL/GA
BORDER...AND THEN PRESSING SOUTHWARD TOWARDS I-10 EARLY THIS
EVENING. MID-LEVEL RIDGING SHOULD KEEP LATE AFTERNOON ACTIVITY
ISOLATED TO WIDELY SCATTERED IN NATURE FOR NORTH CENTRAL FL. MODEL
SOUNDINGS ALL DEPICT AN IMPRESSIVE VEERED WIND PROFILE WITH
MARGINAL INSTABILITY. THE STORM PREDICTION CENTER HAS PLACED ALL
OF SOUTHEAST GA WITHIN A SLIGHT RISK FOR SEVERE THUNDERSTORM
DEVELOPMENT...WITH DAMAGING WINDS AND HAIL BEING THE BIGGEST
THREATS. ALTHOUGH PLENTY OF HIGH DEBRIS CLOUDS WILL STREAM ACROSS
OUR REGION TODAY...HIGHS SHOULD CLIMB INTO THE MID/UPPER 80S
BEFORE CONVECTION DEVELOPS AS WARM AIR ADVECTION STRENGTHENS.
CONVECTION MAY LINGER WELL INTO THE EVENING ALONG THE INTERSTATE
10 CORRIDOR AND SOUTHEAST GA. AS OUTFLOWS MOVE OVER THE WARM
NORTHEAST GULF WATERS...SOME NOCTURNAL CONVECTION MAY ALSO ATTEMPT
TO PUSH ONSHORE INTO THE FL BIG BEND AND WESTERN SUWANNEE VALLEY
DURING THE PREDAWN HOURS. KEPT GENERAL ISOLATED TO WIDELY
SCATTERED CONVECTIVE COVERAGE IN THE FORECAST GRIDS AFTER
MIDNIGHT. LOWS WILL ONLY FALL INTO THE UPPER 60S TO LOWER 70S AS
STRONG WARM AIR ADVECTION PATTERN PREVAILS.
.SHORT TERM (SUNDAY THROUGH MONDAY NIGHT)...
A COLD FRONT WILL BEGIN SINKING SOUTHWARD FROM THE TENNESSEE
VALLEY REGION. STRONG DEEP-LAYERED W/SW FLOW WILL REMAIN IN PLACE
LOCALLY AHEAD OF THIS FRONT...WITH OUTFLOWS FROM POSSIBLE MORNING
CONVECTION OVER THE NORTHEAST GULF/SUWANNEE VALLEY BEING A
POSSIBLE TRIGGER. EXPECT THE BEST INSTABILITY AND FORCING TO
REMAIN OVER NORTHEAST AND NORTH CENTRAL FL...AND EVOLUTION IS
SOMEWHAT UNCERTAIN. MODEL SOUNDINGS DEPICT MORE INSTABILTY AND A
PERSISTENT VEERING PROFILE...WHICH MAY BE CONDUCIVE TO ANOTHER
ROUND OF STRONG TO SEVERE AFTERNOON CONVECTION. THE STORM
PREDICTION CENTER HAS PLACED OUR ENTIRE AREA WITHIN A MARGINAL
RISK FOR SEVERE THUNDERSTORM DEVELOPMENT...WITH DOWNBURST WINDS
AND HAIL BEING THE PRIMARY THREATS. UNLESS THERE IS A MORE
SUBSTANTIAL MORNING CONVECTIVE EVENT...STRONG OFFSHORE FLOW SHOULD
ALLOW HIGHS TO APPROACH 90 FOR MANY LOCATIONS AS BREAKS IN THE
HIGH DEBRIS CLOUDS DEVELOP BY LATE MORNING.
COLD FRONT WILL REACH SE GA SUNDAY EVENING AND PUSH SOUTH NEAR
THE GEORGIA / FLORIDA BORDER EARLY MONDAY MORNING. THIS FRONT IS
EXPECTED TO SEEP SLOWLY THROUGH NE FLORIDA THROUGH THE DAY MONDAY.
AS THE FRONT DOES SEEP SOUTHWARD...LOCAL CONVERGENCE ALONG THE
BOUNDARY WILL LEND TO ISOLATED SHOWERS MAINLY SOUTH OF INTERSTATE
10 AND MORE WIDELY SCATTERED SHOWERS/TSTMS ACROSS THE EXTREME
SOUTHERN TIER ZONES WHERE SOME POOLING MOISTURE AND CONVERGENCE
WILL RESIDE. DRIER AIR WELL NORTH OF THE FRONT WILL KEEP IT DRY
NORTH OF I-10 ON MONDAY. THE ISODROSOTHERM GRADIENT MONDAY WILL
RANGE FROM THE MID 50S ACROSS INTERIOR SE GA ZONES TO MID /UPPER
60S ACROSS NORTH CENTRAL FLORIDA. THIS SAME FRONT STALL ACROSS
NORTH CENTRAL FLORIDA MONDAY NIGHT WITH ISOLATED SHOWERS WITH SOME
EMBEDDED THUNDER WITH CONTINUED SFC CONVERGENCE ALONG THE STALLED
FRONT. LOWS MONDAY NIGHT WILL RANGE FROM THE UPPER 50S INTERIOR SE
GA TO MID/UPPER 60S ACROSS THE SOUTHERN ZONES.
.LONG TERM (TUESDAY THROUGH FRIDAY)...
A SOUTHERN TRACK MID/UPPER LEVEL TROF AND ATTENDANT SURFACE LOW WILL
TRACK EASTWARD ALONG THE GULF COAST, GIVING OUR FORECAST AREA A GOOD
CHANCE OF RAIN TUESDAY AND WEDNESDAY.
THE COLD FRONT SOUTH OF THE AREA WILL BEGIN TO RETURN NORTHWARD AS A
WARM FRONT TUESDAY AFTERNOON AND EVENING IN RESPONSE TO THE
AFOREMENTIONED WESTERN GULF OF MEXICO LOW SLIDING EAST TOWARDS
OUR REGION. THE POTENTIAL WILL BE FOR MAINLY SCATTERED TUESDAY
AFTERNOON SHOWERS AT MOST LOCATIONS WITH MORE NUMEROUS SHOWERS
POSSIBLE WEST OF THE I-75 CORRIDOR.
SCATTERED TO NUMEROUS SHOWERS WILL BE POSSIBLE ACROSS THE ENTIRE
AREA TUESDAY NIGHT AS THE NORTHWARD MOVING WARM FRONT BECOMES MORE
DEFINED. THE 00 UTC ECMWF CONTINUES FARTHER NORTH AND PROGRESSIVE
WITH THE SURFACE REFLECTION THAN THE GFS SOLUTION...WHICH
POSITIONS MUCH OF NE FL IN THE WARM SECTOR. WILL CONTINUE TO
MONITOR MODEL TRENDS ON THIS. ECMWF SOLUTION BRING MORE OF A
THREAT OF SEVERE STORMS FOR PORTIONS NE FL DUE TO THE MORE
NORTHERN TRACK.
THE GULF LOW WILL MOVE OVER THE AREA WEDNESDAY AS WEST-SOUTHWEST
FLOW TAPS INTO SUBTROPICAL MOISTURE AND PWATS COME UP TO CLOSE TO
1.8" WITH SCATTERED TO NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORM
ACTIVITY ANTICIPATED. THE CLOUDS AND RAIN WILL KEEP HIGH
TEMPERATURES A LITTLE COOLER WEDNESDAY...WITH MAXES MAINLY IN
THE 70S EXCEPT NEAR 80 SOUTHERN ZONES .
A SLIGHTLY COOLER AND MUCH DRIER AIR MASS WILL PLUNGE INTO OUR
REGION LATE NEXT WEEK...WITH HIGHS GENERALLY IN THE 70S AND LOWS
FALLING TO THE 55-60 RANGE FRIDAY MORNING.
&&
.AVIATION...
PERIODS OF MVFR/BRIEF IFR VISIBILITIES WILL PERSIST AT VQQ
THROUGH 11Z. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH AT
LEAST 16Z AT THE REGIONAL TERMINALS. A BRIEF PERIOD OF LOW LEVEL
WIND SHEAR IS POSSIBLE AT THE TERMINALS BETWEEN 09Z-12Z AS
SOUTHERLY WINDS INCREASE TO NEAR 30 KTS JUST OFF THE SURFACE. WILL
MONITOR THIS CLOSELY AND AMEND IF NECESSARY. SOUTHERLY SURFACE
WINDS WILL INCREASE TO NEAR 10 KNOTS AND GUSTY AFTER SUNRISE...AND
THEN SOUTHWESTERLY NEAR 15 KNOTS WITH OCCASIONAL GUSTS UP TO 25
KNOTS AT THE TERMINALS TOWARDS 16Z. THUNDERSTORMS MAY APPROACH SSI
TOWARDS 18Z...WITH STRONG WIND GUSTS POSSIBLE. THIS ACTIVITY MAY
IMPACT THE DUVAL COUNTY TERMINALS AFTER 21Z. INCLUDED PROB30
GROUPS FOR GUSTY WINDS AND SUB-VFR CONDITIONS AT THESE TERMINALS
THROUGHOUT THE LATE AFTERNOON HOURS. THUNDERSTORMS MAY ALSO IMPACT
GNV AND SGJ AFTER 19Z...BUT CONFIDENCE IN TIMING AND INTENSITY
REMAIN IN QUESTION. ACTIVITY MAY LINGER INTO THE EARLY EVENING
HOURS.
&&
.MARINE...
SOUTHERLY WINDS WILL STRENGTHEN THIS MORNING AND WILL BECOME
SOUTHWESTERLY THIS AFTERNOON. SPEEDS WILL APPROACH CAUTION IN THE
NEAR SHORE WATERS...WITH CAUTION SPEEDS OF 15-20 KNOTS EXPECTED
OFFSHORE BY LATE MORNING. STRONG TO SEVERE THUNDERSTORMS MAY PUSH
INTO THE NEAR SHORE WATERS LATE THIS AFTERNOON INTO THE EVENING
HOURS...PARTICULARLY IN THE WATERS ADJACENT TO SOUTHEAST GA. WINDS
WILL BECOME SOUTHWEST TO WEST THIS EVENING AND WILL SURGE TO
CAUTION LEVELS NEAR SHORE AND SMALL CRAFT ADVISORY LEVELS OFFSHORE
BY LATE EVENING. SEAS OFFSHORE WILL PEAK IN THE 4-6 FT RANGE LATER
TODAY AND TONIGHT...WITH OCCASIONAL SEAS UP TO 8 FEET POSSIBLE.
CAUTION LEVEL SOUTHWEST TO WEST WINDS WILL PREVAIL OFFSHORE SUNDAY
AFTERNOON AND NIGHT AHEAD OF AN APPROACHING COLD FRONT...WITH
WINDS REMAINING NEAR CAUTION SPEEDS NEAR SHORE. THE FRONT WILL
MOVE SOUTH OF THE COASTAL WATERS BY EARLY MONDAY...WITH WINDS
BECOMING NORTH TO NORTHEAST AND SUBSIDING BELOW CAUTION SPEEDS.
LOW PRESSURE WILL DEVELOP OVER THE GULF OF MEXICO EARLY NEXT WEEK
AND WILL LIKELY MOVE TOWARDS OUR REGION BY MIDWEEK. WINDS WILL
VEER TO A SOUTHEASTERLY AND THEN SOUTHERLY DIRECTION BY LATE
TUESDAY AND WEDNESDAY.
RIP CURRENTS: MODERATE RISK CONTINUES TODAY DUE TO A LINGERING
LONG PERIOD EASTERLY SWELL AROUND 2 FEET WITH A 13-15 SECOND
PERIOD. LOW RISK ANTICIPATED ON SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 85 69 90 64 / 60 60 20 10
SSI 82 70 86 64 / 60 60 20 10
JAX 89 70 90 66 / 50 50 40 20
SGJ 86 71 89 69 / 40 30 40 20
GNV 87 72 88 69 / 30 30 40 30
OCF 88 70 87 70 / 20 30 30 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT SUNDAY
FOR WATERS FROM ALTAMAHA SOUND GA TO FERNANDINA BEACH FL
FROM 20 TO 60 NM-WATERS FROM FERNANDINA BEACH TO ST.
AUGUSTINE FL FROM 20 TO 60 NM-WATERS FROM ST. AUGUSTINE TO
FLAGLER BEACH FL FROM 20 TO 60 NM.
&&
$$
NELSON/CORDERO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
211 AM CDT SAT APR 25 2015
.UPDATE...
736 PM...EVENING UPDATE...BUMPED POPS UP QUITE A BIT FOR THIS
EVENING. UPPER WAVE MOVING ACROSS THE AREA PRODUCING CONVECTIVE
SHOWERS WITH SOME EMBEDDED LIGHTNING NEAR THE QUAD CITIES.
INSTABILITY ALOFT SHOULD WEAKEN AS THIS WAVE SHIFTS EAST...BUT DID
ADD A SLIGHT CHANCE OF THUNDER ACROSS THE SOUTHWEST CWA THRU MID
EVENING. WHILE THE LOW LEVELS REMAIN DRY INITIALLY...RAINFALL IS
SUFFICIENT TO MOISTEN THE LOW LEVELS WITH DEWPOINTS RISING THRU
THE 30S ACROSS NORTHWEST IL AND RFD MEASURED 0.14 OF RAIN THRU
00Z. HOWEVER...THE DRY LOW LEVELS COULD LEAD TO SOME BRIEF/MIXED
SLEET AT ONSET. HRRR HAS BEEN HANDLING THIS WAVE AND ITS
ASSOCIATED PRECIP QUITE WELL AND SHOWS PRECIP SHIFTING EAST OF THE
AREA BY LATE EVENING SO TRENDED POPS BACK LOWER TOWARD MIDNIGHT.
THEN RAIN CHANCES INCREASE IN THE PREDAWN HOURS INTO SATURDAY
MORNING AS THE MAIN LOW ARRIVES AND MADE NO CHANGES TO THIS TIME
PERIOD.
TEMPS HAVE ALREADY DROPPED INTO THE LOWER/MID 40S WHERE RAIN IS
FALLING AND WILL LIKELY NEED TO MAKE SOME DOWNWARD ADJUSTMENTS TO
TEMPS FOR TONIGHT...ESPECIALLY NORTH OF I-80. CMS
&&
.SHORT TERM...
323 PM CDT
THROUGH SATURDAY NIGHT...
SHORT TERM...THROUGH SATURDAY NIGHT...
PRIMARY FORECAST CONCERN IS WITH FAIRLY STRONG LOW PRESSURE
SYSTEM TRACKING SOUTH OF THE AREA ON SATURDAY AND ASSOCIATED RAIN
AND AMOUNTS.
DRY AIR MASS REMAINS OVER THE AREA THIS AFTERNOON...BUT WITH
GRADUAL MOISTENING FROM BONE DRY CONDITIONS EARLIER TODAY THAT
WERE AMONGST DRIEST IN ENTIRE COUNTRY. W/V IMAGERY SHOWS SHORT
WAVE/MIDLEVEL SPEED MAX INTO EASTERN IA THAT IS RESULTING IN
OCCASIONAL VERY LIGHT RAIN/SPRINKLES REACHING THE GROUND DESPITE
LARGE DEWPOINT DEPRESSIONS. SUSPECT THAT HRRR MODEL IS TOO
AGGRESSIVE WITH HIGHER REFLECTIVITY/RAIN REACHING THE GROUND SOUTH
OF I-88 OR SO AND FOCUS FOR MOST ISOLATED TO SCATTERED ACTIVITY
SHOULD BE IN FAR NORTHERN CWA.
LATER THIS EVENING INTO THE OVERNIGHT...AREA WILL BE IN BROAD
WARM ADVECTION ALOFT BUT ALSO LACKING FOCUS FOR PRECIP WITH
MIDLEVEL RIDGING OVERHEAD. SUSPECT THAT THERE WILL BE SEVERAL
MAINLY DRY HOURS WITH PERHAPS A FEW ISOLATED SHOWERS. THEN MAIN
WAVE WILL START TO SPREAD IN FROM SOUTHWEST AFTER MIDNIGHT INTO
SATURDAY MORNING AS CLOSED LOW AND ASSOCIATED SFC LOW MIGRATES
ACROSS LOWER MO VALLEY. PRECIP WILL BE FIGHTING DRY EASTERLY LOW
LEVEL FLOW ESPECIALLY IN NORTHEAST CWA...BUT THEN AS 700 MB FGEN
STRENGTHENS AND TROWAL LIKE FEATURE SPREADS ~1 TO ~1.25 INCH PWATS
ACROSS AREA...EXPECTING MID-LATE SATURDAY AM TO BE ACCOMPANIED BY
PERIODS OF RAIN/RAIN SHOWERS AND STEADY TO EVEN BRIEFLY HEAVY
RATES. VERY MINIMAL ELEVATED INSTABILITY WILL BE PRESENT WELL
SOUTH OF I-80...SO HAVE MAINTAINED SLIGHT EMBEDDED THUNDER CHANCES
THERE. STILL HAVE HIGH END LIKELY TO CAT POPS IN LATE
AFTERNOON...BUT DRIER AIR WORKING IN FROM NORTH SHOULD REDUCE
RATES...WITH PRECIP QUICKLY SHIFTING SOUTH DURING EVENING AND
SKIES CLEARING TOWARD EARLY SUNDAY.
RAIN AMOUNTS FROM MAIN SYSTEM LATE TONIGHT THROUGH SATURDAY
SHOULD RANGE FROM ABOUT 1/2 INCH IN FAR NORTHEAST TO A BIT UPWARDS
OF ONE INCH IN SOUTHWEST 1/4 TO 1/3 OF CWA. CONFIDENCE IN LOW-
MEDIUM IN THESE AMOUNTS GIVEN POTENTIAL FOR BANDING PLACEMENT TO
SHIFT.
REGARDING TEMPS...INCREASING CLOUDS WILL LIMIT FALL TONIGHT...SO
GENERALLY IN 40S TONIGHT EXCEPT UPPER 30S NEAR LAKE COUNTY SHORE.
CLOUDS...RAIN AND GUSTY NORTHEAST FLOW WILL MAKE FOR RAW
CONDITIONS ON SATURDAY AND HIGHS ONLY RECOVERING TO THE LOW/MID
40S TO LOWER 50S...COOLEST ON ILLINOIS SHORE AND WARMEST SOUTH OF
I-80. TEMPS WILL THEN DIP BACK TO THE 30S BY EARLY SUNDAY WITH H8
TEMPS FALLING TO JUST BELOW 0 CELSIUS. EXPECTING SOME NORTHERN
INTERIOR LOCATIONS TO DIP TO AROUND FREEZING. OVERALL IT WILL BE
ANOTHER NIGHT TO PROTECT COLD SENSITIVE VEGETATION.
RC
&&
.LONG TERM...
333 PM CDT
SUNDAY THROUGH FRIDAY...
EXTENDED PERIOD THROUGH AT LEAST THURSDAY WILL BE DOMINATED BY
ONSHORE FLOW AND COOLER CONDITIONS NEAR THE LAKE...BUT ALSO
GRADUAL WARMING INLAND. WITH POSSIBLY MINOR EXCEPTION OF
WEDNESDAY...CONDITIONS SHOULD BE PRIMARILY DRY AS WELL. AIRMASS
WILL BE COOLEST SUNDAY THROUGH EARLY MONDAY...WITH ONLY MID-UPPER
40S ALONG SHORE AND MID-UPPER 50S INLAND AND THEN OVERNIGHT LOWS
SUNDAY NIGHT AWAY FROM CHICAGO HEAT ISLAND IN LOWER-MID 30S. AS
HIGH PRESSURE DROPS SOUTHEAST TOWARD EARLY MONDAY...WINDS MAY
DIMINISH ENOUGH TO SUPPORT AT LEAST PATCHY FROST...BUT HAVE NOT
ADDED IT TO GRIDS YET. INLAND HIGHS SHOULD BE INTO THE 60S EACH
DAY MON-THU AND TEMPS COULD APPROACH 70 NEXT FRIDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* FARLY STOUT EASTERLY WINDS TODAY.
* POTENTIAL FOR SOME RAIN AND A PERIOD OF IFR CIGS POSSIBLE LATER
THIS MORNING INTO THE EARLY AFTERNOON. CONDITIONS IMPROVE LATER
THIS AFTERNOON AND EVENING.
KJB
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SHIFT EASTWARD ACROSS
THE LOWER MISSOURI VALLEY TODAY...AND TO THE OHIO VALLEY BY THIS
EVENING. THIS SYSTEM WILL CONTINUE TO PRODUCE GUSTY EASTERLY WINDS
TODAY...THEN BECOMING MORE NORTH-NORTHEAST BY LATER THIS EVENING.
CONFIDENCE IN THE WIND FORECAST CONTINUES TO BE FAIRLY HIGH.
HOWEVER...CONFIDENCE ON TIMING AND OCCURRENCE OF IFR TO LIFR CIGS
AND MODERATE RAINFALL IS DECREASING A BIT.
SCATTERED SHOWERS SHOULD CONTINUE TO DEVELOP DURING THE OVERNIGHT
HOURS...MAINLY NEAR AND JUST SOUTH OF THE I-80 CORRIDOR AS
MOISTURE CONTINUES TO CONVERGE IN THIS AREA AROUND 700 MB. THIS
ACTIVITY COULD TRY TO MOVE NORTHEAST TOWARDS THE MAIN TERMINALS
JUST PRIOR TO DAYBREAK PRIOR TO WEAKENING. HOWEVER...IT DOES
APPEAR THAT THE BEST AXIS OF SHOWERS WILL REMAIN TO THE SOUTH OF
MOST OF THE TERMINALS...WITH KMDW AND KGYY ENDING UP THE CLOSET TO
THIS AREA OF RAIN. DUE TO UNCERTAINTIES ON HOW FAR NORTH THIS
ACTIVITY IS ABLE TO GET TOWARDS MORNING I HAVE LEFT IN THE MENTION
OF VCSH.
ANOTHER WAVE OF RAIN WILL LIKELY DEVELOP AROUND OR SHORTLY AFTER
DAYBREAK ACROSS CENTRAL ILLINOIS...THEN LIFT NORTHWARD TOWARDS THE
TERMINALS THROUGH THE MORNING HOURS. HOWEVER...IT APPEARS THAT THE
MOST FAVORABLE AXIS OF BETTER RAINFALL MAY END UP A BIT FARTHER
SOUTH THEN WHAT WAS ORIGINALLY THOUGHT. THEREFORE...THERE IS SOME
INCREASED UNCERTAINTY ON THE NORTHWARD EXTENT OF THE RAINFALL
OVER FAR NORTHERN ILLINOIS. AT THIS TIME...I HAVE ONLY BACKED OFF
SLIGHTLY ON RAIN INTENSITY...BUT ADDITIONAL CHANGES MAY BE NEEDED
IF IT CONTINUES TO LOOK LIKE THE PRECIP MAY REMAIN FARTHER SOUTH.
THIS COULD ALSO MEAN CIGS DO NOT DETERIORATE AS MUCH AS CURRENTLY
FORECAST.
ANY RAIN AND LOW CIGS THAT DO DEVELOP OVER THE AREA SHOULD IMPROVE
EITHER BY LATER THIS AFTERNOON...OR BY EARLY THIS EVENING AS DRIER
AIR WORKS BACK OVER THE REGION.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MED-HIGH WITH WIND FORECAST.
* LOW-MED WITH RAIN EXTENT OVER THE TERMINALS.
* MED WITH CIG FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. GUSTY NORTH-NORTHEAST WINDS 20-25 KTS.
MONDAY...VFR. NORTHEAST WINDS.
TUESDAY...VFR. NORTHEAST WINDS BECOMING EAST.
WEDNESDAY...SLGT CHC -RA. BRIEF MVFR POSSIBLE. NORTH-NORTHWEST
WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
RATZER
&&
.MARINE...
210 AM CDT
THE MAIN WEATHER CONCERNS OVER LAKE MICHIGAN WILL BE TODAY THROUGH
SUNDAY. AN AREA OF LOW PRESSURE WILL SHIFT EASTWARD FROM THE CENTRAL
PLAINS ACROSS THE CENTRAL MISSISSIPPI VALLEY TODAY...THEN OVER THE
THE OHIO VALLEY TONIGHT. OVERALL...THIS WILL RESULT IN SOME STRONGER
EAST-NORTHEASTERLY WINDS TODAY...FOLLOWED BY NORTHERLY WINDS LATER
TONIGHT INTO SUNDAY. WIND SPEEDS LOOK TO GENERALLY BE UP TO AROUND
25 KT THROUGH THE PERIOD. HOWEVER...THE ONSHORE COMPONENT TO THESE
WINDS COULD RESULT IN LARGER WAVES UP TO AROUND OR A BIT ABOVE 4
FEET ALONG THE ILLINOIS AND INDIANA NEAR SHORE WATERS THROUGH THE
WEEKEND.
THE WEATHER PATTERN FOR MUCH OF NEXT WEEK LOOKS TO FEATURE A RATHER
WEAK PRESSURE GRADIENT OVER THE REGION AS HIGH PRESSURE DOMINATES.
THIS SHOULD RESULT IN A VERY WEAK WIND REGIME FOR MUCH OF THE
PERIOD...AND HENCE WIND SPEEDS AND DIRECTIONS WILL LIKELY BE LARGELY
DRIVEN BY LAKE AND LAND BREEZE INFLUENCES.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
102 AM CDT SAT APR 25 2015
.UPDATE...
736 PM...EVENING UPDATE...BUMPED POPS UP QUITE A BIT FOR THIS
EVENING. UPPER WAVE MOVING ACROSS THE AREA PRODUCING CONVECTIVE
SHOWERS WITH SOME EMBEDDED LIGHTNING NEAR THE QUAD CITIES.
INSTABILITY ALOFT SHOULD WEAKEN AS THIS WAVE SHIFTS EAST...BUT DID
ADD A SLIGHT CHANCE OF THUNDER ACROSS THE SOUTHWEST CWA THRU MID
EVENING. WHILE THE LOW LEVELS REMAIN DRY INITIALLY...RAINFALL IS
SUFFICIENT TO MOISTEN THE LOW LEVELS WITH DEWPOINTS RISING THRU
THE 30S ACROSS NORTHWEST IL AND RFD MEASURED 0.14 OF RAIN THRU
00Z. HOWEVER...THE DRY LOW LEVELS COULD LEAD TO SOME BRIEF/MIXED
SLEET AT ONSET. HRRR HAS BEEN HANDLING THIS WAVE AND ITS
ASSOCIATED PRECIP QUITE WELL AND SHOWS PRECIP SHIFTING EAST OF THE
AREA BY LATE EVENING SO TRENDED POPS BACK LOWER TOWARD MIDNIGHT.
THEN RAIN CHANCES INCREASE IN THE PREDAWN HOURS INTO SATURDAY
MORNING AS THE MAIN LOW ARRIVES AND MADE NO CHANGES TO THIS TIME
PERIOD.
TEMPS HAVE ALREADY DROPPED INTO THE LOWER/MID 40S WHERE RAIN IS
FALLING AND WILL LIKELY NEED TO MAKE SOME DOWNWARD ADJUSTMENTS TO
TEMPS FOR TONIGHT...ESPECIALLY NORTH OF I-80. CMS
&&
.SHORT TERM...
323 PM CDT
THROUGH SATURDAY NIGHT...
SHORT TERM...THROUGH SATURDAY NIGHT...
PRIMARY FORECAST CONCERN IS WITH FAIRLY STRONG LOW PRESSURE
SYSTEM TRACKING SOUTH OF THE AREA ON SATURDAY AND ASSOCIATED RAIN
AND AMOUNTS.
DRY AIR MASS REMAINS OVER THE AREA THIS AFTERNOON...BUT WITH
GRADUAL MOISTENING FROM BONE DRY CONDITIONS EARLIER TODAY THAT
WERE AMONGST DRIEST IN ENTIRE COUNTRY. W/V IMAGERY SHOWS SHORT
WAVE/MIDLEVEL SPEED MAX INTO EASTERN IA THAT IS RESULTING IN
OCCASIONAL VERY LIGHT RAIN/SPRINKLES REACHING THE GROUND DESPITE
LARGE DEWPOINT DEPRESSIONS. SUSPECT THAT HRRR MODEL IS TOO
AGGRESSIVE WITH HIGHER REFLECTIVITY/RAIN REACHING THE GROUND SOUTH
OF I-88 OR SO AND FOCUS FOR MOST ISOLATED TO SCATTERED ACTIVITY
SHOULD BE IN FAR NORTHERN CWA.
LATER THIS EVENING INTO THE OVERNIGHT...AREA WILL BE IN BROAD
WARM ADVECTION ALOFT BUT ALSO LACKING FOCUS FOR PRECIP WITH
MIDLEVEL RIDGING OVERHEAD. SUSPECT THAT THERE WILL BE SEVERAL
MAINLY DRY HOURS WITH PERHAPS A FEW ISOLATED SHOWERS. THEN MAIN
WAVE WILL START TO SPREAD IN FROM SOUTHWEST AFTER MIDNIGHT INTO
SATURDAY MORNING AS CLOSED LOW AND ASSOCIATED SFC LOW MIGRATES
ACROSS LOWER MO VALLEY. PRECIP WILL BE FIGHTING DRY EASTERLY LOW
LEVEL FLOW ESPECIALLY IN NORTHEAST CWA...BUT THEN AS 700 MB FGEN
STRENGTHENS AND TROWAL LIKE FEATURE SPREADS ~1 TO ~1.25 INCH PWATS
ACROSS AREA...EXPECTING MID-LATE SATURDAY AM TO BE ACCOMPANIED BY
PERIODS OF RAIN/RAIN SHOWERS AND STEADY TO EVEN BRIEFLY HEAVY
RATES. VERY MINIMAL ELEVATED INSTABILITY WILL BE PRESENT WELL
SOUTH OF I-80...SO HAVE MAINTAINED SLIGHT EMBEDDED THUNDER CHANCES
THERE. STILL HAVE HIGH END LIKELY TO CAT POPS IN LATE
AFTERNOON...BUT DRIER AIR WORKING IN FROM NORTH SHOULD REDUCE
RATES...WITH PRECIP QUICKLY SHIFTING SOUTH DURING EVENING AND
SKIES CLEARING TOWARD EARLY SUNDAY.
RAIN AMOUNTS FROM MAIN SYSTEM LATE TONIGHT THROUGH SATURDAY
SHOULD RANGE FROM ABOUT 1/2 INCH IN FAR NORTHEAST TO A BIT UPWARDS
OF ONE INCH IN SOUTHWEST 1/4 TO 1/3 OF CWA. CONFIDENCE IN LOW-
MEDIUM IN THESE AMOUNTS GIVEN POTENTIAL FOR BANDING PLACEMENT TO
SHIFT.
REGARDING TEMPS...INCREASING CLOUDS WILL LIMIT FALL TONIGHT...SO
GENERALLY IN 40S TONIGHT EXCEPT UPPER 30S NEAR LAKE COUNTY SHORE.
CLOUDS...RAIN AND GUSTY NORTHEAST FLOW WILL MAKE FOR RAW
CONDITIONS ON SATURDAY AND HIGHS ONLY RECOVERING TO THE LOW/MID
40S TO LOWER 50S...COOLEST ON ILLINOIS SHORE AND WARMEST SOUTH OF
I-80. TEMPS WILL THEN DIP BACK TO THE 30S BY EARLY SUNDAY WITH H8
TEMPS FALLING TO JUST BELOW 0 CELSIUS. EXPECTING SOME NORTHERN
INTERIOR LOCATIONS TO DIP TO AROUND FREEZING. OVERALL IT WILL BE
ANOTHER NIGHT TO PROTECT COLD SENSITIVE VEGETATION.
RC
&&
.LONG TERM...
333 PM CDT
SUNDAY THROUGH FRIDAY...
EXTENDED PERIOD THROUGH AT LEAST THURSDAY WILL BE DOMINATED BY
ONSHORE FLOW AND COOLER CONDITIONS NEAR THE LAKE...BUT ALSO
GRADUAL WARMING INLAND. WITH POSSIBLY MINOR EXCEPTION OF
WEDNESDAY...CONDITIONS SHOULD BE PRIMARILY DRY AS WELL. AIRMASS
WILL BE COOLEST SUNDAY THROUGH EARLY MONDAY...WITH ONLY MID-UPPER
40S ALONG SHORE AND MID-UPPER 50S INLAND AND THEN OVERNIGHT LOWS
SUNDAY NIGHT AWAY FROM CHICAGO HEAT ISLAND IN LOWER-MID 30S. AS
HIGH PRESSURE DROPS SOUTHEAST TOWARD EARLY MONDAY...WINDS MAY
DIMINISH ENOUGH TO SUPPORT AT LEAST PATCHY FROST...BUT HAVE NOT
ADDED IT TO GRIDS YET. INLAND HIGHS SHOULD BE INTO THE 60S EACH
DAY MON-THU AND TEMPS COULD APPROACH 70 NEXT FRIDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* FARLY STOUT EASTERLY WINDS TODAY.
* POTENTIAL FOR SOME RAIN AND A PERIOD OF IFR CIGS POSSIBLE LATER
THIS MORNING INTO THE EARLY AFTERNOON. CONDITIONS IMPROVE LATER
THIS AFTERNOON AND EVENING.
KJB
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE OVER THE CENTRAL PLAINS WILL SHIFT EASTWARD ACROSS
THE LOWER MISSOURI VALLEY TODAY...AND TO THE OHIO VALLEY BY THIS
EVENING. THIS SYSTEM WILL CONTINUE TO PRODUCE GUSTY EASTERLY WINDS
TODAY...THEN BECOMING MORE NORTH-NORTHEAST BY LATER THIS EVENING.
CONFIDENCE IN THE WIND FORECAST CONTINUES TO BE FAIRLY HIGH.
HOWEVER...CONFIDENCE ON TIMING AND OCCURRENCE OF IFR TO LIFR CIGS
AND MODERATE RAINFALL IS DECREASING A BIT.
SCATTERED SHOWERS SHOULD CONTINUE TO DEVELOP DURING THE OVERNIGHT
HOURS...MAINLY NEAR AND JUST SOUTH OF THE I-80 CORRIDOR AS
MOISTURE CONTINUES TO CONVERGE IN THIS AREA AROUND 700 MB. THIS
ACTIVITY COULD TRY TO MOVE NORTHEAST TOWARDS THE MAIN TERMINALS
JUST PRIOR TO DAYBREAK PRIOR TO WEAKENING. HOWEVER...IT DOES
APPEAR THAT THE BEST AXIS OF SHOWERS WILL REMAIN TO THE SOUTH OF
MOST OF THE TERMINALS...WITH KMDW AND KGYY ENDING UP THE CLOSET TO
THIS AREA OF RAIN. DUE TO UNCERTAINTIES ON HOW FAR NORTH THIS
ACTIVITY IS ABLE TO GET TOWARDS MORNING I HAVE LEFT IN THE MENTION
OF VCSH.
ANOTHER WAVE OF RAIN WILL LIKELY DEVELOP AROUND OR SHORTLY AFTER
DAYBREAK ACROSS CENTRAL ILLINOIS...THEN LIFT NORTHWARD TOWARDS THE
TERMINALS THROUGH THE MORNING HOURS. HOWEVER...IT APPEARS THAT THE
MOST FAVORABLE AXIS OF BETTER RAINFALL MAY END UP A BIT FARTHER
SOUTH THEN WHAT WAS ORIGINALLY THOUGHT. THEREFORE...THERE IS SOME
INCREASED UNCERTAINTY ON THE NORTHWARD EXTENT OF THE RAINFALL
OVER FAR NORTHERN ILLINOIS. AT THIS TIME...I HAVE ONLY BACKED OFF
SLIGHTLY ON RAIN INTENSITY...BUT ADDITIONAL CHANGES MAY BE NEEDED
IF IT CONTINUES TO LOOK LIKE THE PRECIP MAY REMAIN FARTHER SOUTH.
THIS COULD ALSO MEAN CIGS DO NOT DETERIORATE AS MUCH AS CURRENTLY
FORECAST.
ANY RAIN AND LOW CIGS THAT DO DEVELOP OVER THE AREA SHOULD IMPROVE
EITHER BY LATER THIS AFTERNOON...OR BY EARLY THIS EVENING AS DRIER
AIR WORKS BACK OVER THE REGION.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MED-HIGH WITH WIND FORECAST.
* LOW-MED WITH RAIN EXTENT OVER THE TERMINALS.
* MED WITH CIG FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR. GUSTY NORTH-NORTHEAST WINDS 20-25 KTS.
MONDAY...VFR. NORTHEAST WINDS.
TUESDAY...VFR. NORTHEAST WINDS BECOMING EAST.
WEDNESDAY...SLGT CHC -RA. BRIEF MVFR POSSIBLE. NORTH-NORTHWEST
WINDS.
THURSDAY...VFR. NORTH-NORTHEAST WINDS.
RATZER
&&
.MARINE...
215 PM CDT
HIGH PRESSURE MOVING ACROSS THE CENTRAL GREAT LAKES REGION HAS SET
UP GENERALLY LIGHT AND VARIABLE WINDS OVER LAKE MICHIGAN. THE
LIGHT WINDS REGIME AND LAND-LAKE DIFFERENTIAL HEATING HAS SET UP A
LAKE BREEZE WITH NEARSHORE WINDS TAKING AN ONSHORE ORIENTATION
THIS AFTERNOON. AS THE HIGH MOVES OFF TO THE EAST TONIGHT...LOW
PRESSURE OVER THE CENTRAL PLAINS WILL DEEPEN AND MOVE EAST TO NWRN
MO OVERNIGHT TONIGHT. A DEVELOPING WARM FRONT WILL EXTEND EAST
FROM THE LOW ACROSS CNTRL IL/IN...WITH WINDS BECOMING EASTERLY BY
LATE TONIGHT. THE WARM FRONT IS EXPECTED TO REMAIN NEARLY
STATIONARY AS THE LOW TRACKS EWD...KEEPING WINDS OVER THE LAKE
ELY. AS THE LOW PASSES SOUTH OF THE LAKE AND A RIDGE OF HIGH
PRESSURE BUILDS FROM HUDSON BAY THROUGH THE NRN GREAT LAKES...WIND
SPEEDS WILL INCREASE WITH THE STRONGEST WINDS OF 25-30 KT OVER THE
SRN PORTIONS OF THE LAKE. AS THE LOW PASSES EAST THROUGH THE OHIO
VALLEY SATURDAY NIGHT INTO SUNDAY MORNING...WINDS WILL BACK TO
NORTHERLY. WHILE GALES ARE NOT LIKELY...WINDS OVER THE SRN
PORTIONS OF THE LAKE WILL BE STRONG ENOUGH TO REQUIRE A SMALL
CRAFT ADVISORY AND EVEN THOUGH WINDS SHOULD WEAKEN BELOW SMALL
CRAFT ADVISORY LEVELS WITH THE SHIFT TO NORTHERLY...THE LONG FETCH
SHOULD BE SUFFICIENT TO KEEP SMALL CRAFT ADVISORY LEVEL WAVES INTO
MONDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE LAKE BY
TUESDAY MORNING AND REMAIN THE DOMINANT FEATURE THROUGH MUCH OF
NEXT WEEK...SETTING A PERIOD OF RELATIVELY QUIET CONDITIONS OVER
THE LAKE FROM TUESDAY THROUGH THE END OF THE FORECAST PERIOD.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
447 AM CDT SAT APR 25 2015
...UPDATED LONG TERM...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 155 AM CDT SAT APR 25 2015
CLEAR TO MOSTLY CLEAR CONDITIONS CAN BE EXPECTED TODAY AS AN
UPPER LEVEL RIDGE AXIS MOVES EAST ACROSS THE CENTRAL HIGH PLAINS.
AT THE SURFACE A WEAK COLD FRONT WILL MOVE ACROSS WESTERN KANSAS
DURING THE AFTERNOON AND SOME SLIGHTLY COOLER AIR IS FORECAST BY
THE 00Z NAM IN THE 900MB TO 850MB LEVEL IN NORTH CENTRAL KANSAS BY
LATE DAY. EVEN WITH THIS SLIGHT COOLING TREND THE 850MB TEMPERATURES
AT 00Z SUNDAY SUGGEST AFTERNOON HIGHS WILL RANGE FROM THE MID 70S
IN NORTH CENTRAL KANSAS TO THE LOWER 80S SOUTH OF HIGHWAY 56. THIS
APPEAR REASONABLE GIVEN THE ABUNDANT SUNSHINE EXPECTED.
TONIGHT THIS SURFACE BOUNDARY WILL BECOME STATIONARY SOUTH OF THE
OKLAHOMA BORDER AND EXTEND FROM SOUTHEAST COLORADO INTO WESTERN
OKLAHOMA. NORTH OF THIS BOUNDARY AN EASTERLY UPSLOPE FLOW WILL
DEVELOP, AND THE NAM AND GFS INDICATES THE LOW LEVEL MOISTURE WILL
BE ON THE INCREASE. DEPTH OF THE NEAR SURFACE MOISTURE BY 12Z
SUNDAY WILL TO BE LESS THAN 3000FT AGL ACROSS SOUTHWEST AND SOUTH
CENTRAL KANSAS SO AT THIS TIME WILL HOLD OF INSERTING
PRECIPITATION CHANCES, DRIZZLE, TONIGHT. OVER WEST CENTRAL AND
PORTIONS OF NORTH CENTRAL KANSAS LATE TONIGHT THE THE DEPTH OF THE
MOIST LAYER WILL BE MARGINAL FOR LIGHT PRECIPITATION. CURRENT
FORECAST CURRENTLY HAVE SLIGHT CHANCES FOR PRECIPITATION NORTHWEST
OF A GARDEN CITY TO RUSH CENTRAL LINE AND SO WILL LEAVE THE
PRECIPITATION FORECAST AS IS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 447 AM CDT SAT APR 25 2015
A STABLE BOUNDARY LAYER WILL BE IN PLACE ON SUNDAY WITH A LACK OF
MID LEVEL INSTABILITY AS WELL, WHICH APPEARS WELL AGREED UPON
BETWEEN THE GFS AND NAM MODELS AT THIS TIME. MODEL FORECAST
SOUNDINGS AND PLAN VIEWS SHOW A SATURATED LOWEST 1000-2500 FT WHILE
CAPPED BY A DRY LAYER ABOVE ABOUT THE 800 MB LEVEL. AL IN ALL A
CLOUDY AND COOL DAY WITH POSSIBLY PATCHY DRIZZLE ESPECIALLY LATER IN
THE DAY AS THE UPPER LOW APPROACHED FROM THE SOUTHERN ROCKIES.
NAM/ECMWF AND GFS ENSEMBLES ALL TAKE THE 500 MB LOW TRACK THROUGH
THE TEXAS PANHANDLE ON MONDAY. THAT TRACK WILL PUT THE SOUTHERN HALF
OF THE DDC FORECAST AREA ON COLD CONVEYOR BELT/ AND UPPER
DEFORMATION AXIS THROUGH MONDAY EVENING. A TRANSITION FROM CLOUDY
AND POSSIBLY DRIZZLE CONDITIONS RAIN SHOWERS AN POTENTIALLY A PERIOD
OF RAIN AND STRONGER CONVECTION IS LIKELY FOR THE SOUTHERN COUNTIES.
THE LAST BLEND SOLUTION INCREASED POPS TO AROUND 70 PERCENT FOR
THESE AREAS. SUCH A PATTERN IS NOT VERY CONDUCIVE FOR SEVERE
WEATHER. COOLEST DAYTIME TEMPERATURES ON MONDAY WILL BE IN THE SOUTH
ALONG THE OKLAHOMA LINE WHERE THE RAIN IS EXPECTED.
BROAD UPPER RIDGING WILL DEVELOP BEYOND MONDAY WITH LITTLE OBVIOUS
SYNOPTIC SUPPORT FOR PRECIPITATION . TEMPERATURES WILL EXHIBIT A
WARMING TREND. MODEL OUTPUT STATISTICS AND MODEL BLEND HIGHS ARE
FORECAST AROUND NORMAL FOR LATE APRIL, BUT WARMING TO THE 80S BY THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1206 AM CDT SAT APR 25 2015
PRECIPITATION CHANCES WILL END FROM WEST TO EAST AND A CLEARING
TREND WILL BEGIN BETWEEN 06Z AND 09Z SATURDAY AS SUBSIDENCE
DEVELOPS BEHIND AN UPPER LEVEL TROUGH AS IT CROSSES CENTRAL KANSAS
EARLY THIS MORNING. 00Z NAM BUFR SOUNDINGS, RAP, AND HRRR WERE ALL
IN GOOD AGREEMENT WITH THIS AND KEEPS CLEAR CONDITIONS ACROSS ALL
OF SOUTHWEST KANSAS THROUGH SATURDAY. IN NORTH CENTRAL KANSAS VFR
CONDITIONS ARE EXPECTED BUT SOME AFTERNOON CLOUDS IN THE 3000 TO
4000FT AGL WILL BE POSSIBLE IN THE HYS AREA. NORTHWESTERLY WINDS
AT 10 TO 15 KNOTS WILL CONTINUE OVERNIGHT AND BY LATE MORNING
DECREASE TO AROUND 10 KNOTS. THESE NORTHWESTERLY WINDS WILL THEN
GRADUALLY VEER TO THE NORTHEAST DURING THE AFTERNOON AS A WEAK
SURFACE BOUNDARY MOVES ACROSS WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 79 48 60 43 / 10 10 20 50
GCK 78 49 57 43 / 10 20 30 50
EHA 78 48 62 43 / 10 10 40 70
LBL 80 50 62 45 / 10 10 30 60
HYS 72 46 56 42 / 10 10 20 30
P28 81 51 66 47 / 10 10 20 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...33
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
159 AM CDT SAT APR 25 2015
...UPDATED SHORT TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 155 AM CDT SAT APR 25 2015
CLEAR TO MOSTLY CLEAR CONDITIONS CAN BE EXPECTED TODAY AS AN
UPPER LEVEL RIDGE AXIS MOVES EAST ACROSS THE CENTRAL HIGH PLAINS.
AT THE SURFACE A WEAK COLD FRONT WILL MOVE ACROSS WESTERN KANSAS
DURING THE AFTERNOON AND SOME SLIGHTLY COOLER AIR IS FORECAST BY
THE 00Z NAM IN THE 900MB TO 850MB LEVEL IN NORTH CENTRAL KANSAS BY
LATE DAY. EVEN WITH THIS SLIGHT COOLING TREND THE 850MB TEMPERATURES
AT 00Z SUNDAY SUGGEST AFTERNOON HIGHS WILL RANGE FROM THE MID 70S
IN NORTH CENTRAL KANSAS TO THE LOWER 80S SOUTH OF HIGHWAY 56. THIS
APPEAR REASONABLE GIVEN THE ABUNDANT SUNSHINE EXPECTED.
TONIGHT THIS SURFACE BOUNDARY WILL BECOME STATIONARY SOUTH OF THE
OKLAHOMA BORDER AND EXTEND FROM SOUTHEAST COLORADO INTO WESTERN
OKLAHOMA. NORTH OF THIS BOUNDARY AN EASTERLY UPSLOPE FLOW WILL
DEVELOP, AND THE NAM AND GFS INDICATES THE LOW LEVEL MOISTURE WILL
BE ON THE INCREASE. DEPTH OF THE NEAR SURFACE MOISTURE BY 12Z
SUNDAY WILL TO BE LESS THAN 3000FT AGL ACROSS SOUTHWEST AND SOUTH
CENTRAL KANSAS SO AT THIS TIME WILL HOLD OF INSERTING
PRECIPITATION CHANCES, DRIZZLE, TONIGHT. OVER WEST CENTRAL AND
PORTIONS OF NORTH CENTRAL KANSAS LATE TONIGHT THE THE DEPTH OF THE
MOIST LAYER WILL BE MARGINAL FOR LIGHT PRECIPITATION. CURRENT
FORECAST CURRENTLY HAVE SLIGHT CHANCES FOR PRECIPITATION NORTHWEST
OF A GARDEN CITY TO RUSH CENTRAL LINE AND SO WILL LEAVE THE
PRECIPITATION FORECAST AS IS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 111 PM CDT FRI APR 24 2015
BY THE BEGINNING OF THE EXTENDED PERIOD, AN UPPER TROUGH WILL BE BE
DEEPENING OVER THE WESTERN STATES THANKS TO A 120+ KNOT JET LOCATED
ON THE WEST SIDE OF THE TROUGH. THIS TROUGH WILL CONTINUE TO DEEPEN
AND CLOSE OFF INTO AN UPPER LOW OVER NEW MEXICO ON SUNDAY BEFORE
MOVING OUT ACROSS THE SOUTHERN PLAINS EARLY NEXT WEEK. AS THE TROUGH
AND LOW DEVELOP, LOW PRESSURE OVER EASTERN COLORADO WILL DROP SOUTH
INTO THE TEXAS PANHANDLE WHILE A COOL FRONT DROPS SOUTH ACROSS
WESTERN KANSAS SATURDAY NIGHT. COOL AND MOIST LOW LEVEL EASTERLY
FLOW WILL DEVELOP OVER SOUTHWEST KANSAS BEHIND THE FRONT. THIS WILL
LEAD TO CLOUDY AND COOLER CONDITIONS ALONG WITH INCREASING CHANCES
FOR SHOWERS AND POSSIBLY A FEW THUNDERSTORMS LATE SUNDAY THROUGH THE
EARLY PART OF NEXT WEEK.
THE MEDIUM RANGE MODELS HAVE BEEN HOLDING ON TO THEIR RESPECTIVE
SOLUTIONS REGARDING THE TRACK OF THE UPPER LOW AS IT MOVES OUT
THROUGH THE SOUTHERN PLAINS MONDAY AND TUESDAY. THE TRACK OF THE LOW
WILL HAVE AN IMPACT ON PRECIPITATION CHANCES AND RAINFALL AMOUNTS
ACROSS SOUTHWEST KANSAS. THE GFS CONTINUES TO BE FARTHEST NORTH WITH
ITS TRACK ACROSS THE TEXAS PANHANDLE THROUGH OKLAHOMA INTO MISSOURI.
THIS MODEL IS SHOWING DECENT RAINFALL ACROSS MUCH OF CENTRAL AND
SOUTHWEST KANSAS. BOTH THE ECMWF AND CANADIAN MODELS TRACK THE UPPER
LOW OUT ACROSS WESTERN AND NORTHERN TEXAS INTO ARKANSAS AND HAVE THE
BEST RAINFALL AMOUNTS CONFINED TO AREAS ALONG AND JUST NORTH OF THE
OKLAHOMA BORDER. THE CURRENT FORECAST THROUGH MONDAY LOOKS
REASONABLE WITH LIKELY POPS NEAR THE OKLAHOMA BORDER THAT DIMINISH
FARTHER NORTH AND HAVE ONLY MADE SOME MINOR ADJUSTMENTS.
GIVEN THE CLOUDY, COOL AND MOIST CONDITIONS THAT DEVELOP, HIGH
TEMPERATURES ON SUNDAY AND MONDAY WILL LIKELY NOT GET OUT OF THE 50S
IN MANY LOCATIONS ESPECIALLY ON MONDAY.
THE REMAINDER OF THE EXTENDED PERIOD SHOULD SEE DRIER AND WARMER
WEATHER RETURNING AS UPPER LEVEL RIDGING BUILDS BACK OVER THE
CENTRAL PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1206 AM CDT SAT APR 25 2015
PRECIPITATION CHANCES WILL END FROM WEST TO EAST AND A CLEARING
TREND WILL BEGIN BETWEEN 06Z AND 09Z SATURDAY AS SUBSIDENCE
DEVELOPS BEHIND AN UPPER LEVEL TROUGH AS IT CROSSES CENTRAL KANSAS
EARLY THIS MORNING. 00Z NAM BUFR SOUNDINGS, RAP, AND HRRR WERE ALL
IN GOOD AGREEMENT WITH THIS AND KEEPS CLEAR CONDITIONS ACROSS ALL
OF SOUTHWEST KANSAS THROUGH SATURDAY. IN NORTH CENTRAL KANSAS VFR
CONDITIONS ARE EXPECTED BUT SOME AFTERNOON CLOUDS IN THE 3000 TO
4000FT AGL WILL BE POSSIBLE IN THE HYS AREA. NORTHWESTERLY WINDS
AT 10 TO 15 KNOTS WILL CONTINUE OVERNIGHT AND BY LATE MORNING
DECREASE TO AROUND 10 KNOTS. THESE NORTHWESTERLY WINDS WILL THEN
GRADUALLY VEER TO THE NORTHEAST DURING THE AFTERNOON AS A WEAK
SURFACE BOUNDARY MOVES ACROSS WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 81 48 61 44 / 0 10 30 50
GCK 78 49 57 44 / 0 20 40 50
EHA 78 48 66 44 / 0 10 50 70
LBL 81 50 67 45 / 0 10 40 60
HYS 72 46 57 42 / 0 10 20 30
P28 82 51 65 47 / 0 10 30 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...GERARD
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1208 AM CDT SAT APR 25 2015
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1206 AM CDT SAT APR 25 2015
AT 00Z SATURDAY A 500MB TROUGH/LOW WAS LOCATED OVER SOUTHWEST
KANSAS. THIS UPPER TROUGH WAS ALSO ASSOCIATED WITH THE LEFT EXIT
REGION OF A 250MB JET. FURTHER WEST A 500MB SHORT WAVE RIDGE AXIS
EXTENDED FROM THE FOUR CORNERS REGION INTO THE NORTHERN ROCKIES.
ANOTHER UPPER LEVEL TROUGH WAS LOCATED OVER THE PACIFIC NORTHWEST.
OVER THE CENTRAL HIGH PLAINS AN AREA OF LOW PRESSURE AT THE
SURFACE WAS LOCATED OVER SOUTHWEST KANSAS WITH A WARM FRONT
EXTENDING EAST/NORTHEAST INTO NORTHERN CENTRAL KANSAS AT 00Z
SATURDAY. A DRYLINE EXTENDED SOUTH FROM THE WARM FRONT AND
STRETCHED FROM NORTH CENTRAL KANSAS INTO NORTHWEST OKLAHOMA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1234 PM CDT FRI APR 24 2015
THE SHORT-FUSE SEVERE WEATHER COMPOSITE AT MIDDAY WAS SHOWING A
THREAT AREA STARTING TO DEVELOP ALONG THE SLOWLY NORTHWARD ADVANCING
WARM FRONT ACROSS WEST-CENTRAL KANSAS. SURFACE-BASED CAPE WAS
APPROACHING 1000 J/KG PER LAPS ANALYSIS AS OF 16Z. A SYNOPTIC DRY
INTRUSION/DRYLINE WILL CONTINUE TO ADVANCE NORTHEASTWARD, SHUNTING
THE SURFACE-BASED INGREDIENTS FOR SEVERE THUNDERSTORMS UP TOWARD THE
I-70 CORRIDOR. BY 21Z, THE HRRR INDICATES DEEP MOIST CONVECTION
DEVELOPING ALONG THE WARM FRONT BY 20-21Z. THERE SHOULD BE PRETTY
GOOD LOW LEVEL SHEAR ALONG THE FRONT WITH AMPLE STREAMWISE VORTICITY
TO INGEST INTO AN INCIPIENT SUPERCELL STORM. THE HRRR HAS SHOWN A
PERSISTENT LONG-TRACK UPDRAFT HELICITY SIGNAL, WHICH WOULD SUPPORT A
FAIRLY LONG-LIVED SUPERCELL THUNDERSTORM. IT CERTAINLY APPEARS THE
BEST TORNADO THREAT WILL BE UP ALONG THE FRONT ALONG THE I-70
CORRIDOR, WITH THE MOST VIGOROUS SURFACE-BASED STORMS EXITING OUR
AREA OF RESPONSIBILITY (EAST OF ELLIS AND RUSH COUNTY) BY AS SOON AS
23Z. WE WILL HAVE TO WATCH THE BENT-BACK REGION OF ENHANCED
CAPE/MOISTURE WESTWARD ALONG I-70 FOR FUTURE GROWTH OF DEEP MOIST
CONVECTION AS SOME OF THE LATEST RUNS OF THE HRRR SUGGEST. THERE
WILL LIKELY BE A LOCALIZED HEAVY RAIN RISK ALONG THE FRONT UP THERE
SHOULD THE HRRR PAN OUT. THE SHORTWAVE TROUGH WILL QUICKLY EXIT THE
SOUTHWEST KANSAS REGION BY LATE EVENING WITH SOME WESTERLY LOW LEVEL
MOMENTUM FINALLY PUSHING INTO OUR REGION ESPECIALLY AFTER 06Z
TONIGHT.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 111 PM CDT FRI APR 24 2015
BY THE BEGINNING OF THE EXTENDED PERIOD, AN UPPER TROUGH WILL BE BE
DEEPENING OVER THE WESTERN STATES THANKS TO A 120+ KNOT JET LOCATED
ON THE WEST SIDE OF THE TROUGH. THIS TROUGH WILL CONTINUE TO DEEPEN
AND CLOSE OFF INTO AN UPPER LOW OVER NEW MEXICO ON SUNDAY BEFORE
MOVING OUT ACROSS THE SOUTHERN PLAINS EARLY NEXT WEEK. AS THE TROUGH
AND LOW DEVELOP, LOW PRESSURE OVER EASTERN COLORADO WILL DROP SOUTH
INTO THE TEXAS PANHANDLE WHILE A COOL FRONT DROPS SOUTH ACROSS
WESTERN KANSAS SATURDAY NIGHT. COOL AND MOIST LOW LEVEL EASTERLY
FLOW WILL DEVELOP OVER SOUTHWEST KANSAS BEHIND THE FRONT. THIS WILL
LEAD TO CLOUDY AND COOLER CONDITIONS ALONG WITH INCREASING CHANCES
FOR SHOWERS AND POSSIBLY A FEW THUNDERSTORMS LATE SUNDAY THROUGH THE
EARLY PART OF NEXT WEEK.
THE MEDIUM RANGE MODELS HAVE BEEN HOLDING ON TO THEIR RESPECTIVE
SOLUTIONS REGARDING THE TRACK OF THE UPPER LOW AS IT MOVES OUT
THROUGH THE SOUTHERN PLAINS MONDAY AND TUESDAY. THE TRACK OF THE LOW
WILL HAVE AN IMPACT ON PRECIPITATION CHANCES AND RAINFALL AMOUNTS
ACROSS SOUTHWEST KANSAS. THE GFS CONTINUES TO BE FARTHEST NORTH WITH
ITS TRACK ACROSS THE TEXAS PANHANDLE THROUGH OKLAHOMA INTO MISSOURI.
THIS MODEL IS SHOWING DECENT RAINFALL ACROSS MUCH OF CENTRAL AND
SOUTHWEST KANSAS. BOTH THE ECMWF AND CANADIAN MODELS TRACK THE UPPER
LOW OUT ACROSS WESTERN AND NORTHERN TEXAS INTO ARKANSAS AND HAVE THE
BEST RAINFALL AMOUNTS CONFINED TO AREAS ALONG AND JUST NORTH OF THE
OKLAHOMA BORDER. THE CURRENT FORECAST THROUGH MONDAY LOOKS
REASONABLE WITH LIKELY POPS NEAR THE OKLAHOMA BORDER THAT DIMINISH
FARTHER NORTH AND HAVE ONLY MADE SOME MINOR ADJUSTMENTS.
GIVEN THE CLOUDY, COOL AND MOIST CONDITIONS THAT DEVELOP, HIGH
TEMPERATURES ON SUNDAY AND MONDAY WILL LIKELY NOT GET OUT OF THE 50S
IN MANY LOCATIONS ESPECIALLY ON MONDAY.
THE REMAINDER OF THE EXTENDED PERIOD SHOULD SEE DRIER AND WARMER
WEATHER RETURNING AS UPPER LEVEL RIDGING BUILDS BACK OVER THE
CENTRAL PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1206 AM CDT SAT APR 25 2015
PRECIPITATION CHANCES WILL END FROM WEST TO EAST AND A CLEARING
TREND WILL BEGIN BETWEEN 06Z AND 09Z SATURDAY AS SUBSIDENCE
DEVELOPS BEHIND AN UPPER LEVEL TROUGH AS IT CROSSES CENTRAL KANSAS
EARLY THIS MORNING. 00Z NAM BUFR SOUNDINGS, RAP, AND HRRR WERE ALL
IN GOOD AGREEMENT WITH THIS AND KEEPS CLEAR CONDITIONS ACROSS ALL
OF SOUTHWEST KANSAS THROUGH SATURDAY. IN NORTH CENTRAL KANSAS VFR
CONDITIONS ARE EXPECTED BUT SOME AFTERNOON CLOUDS IN THE 3000 TO
4000FT AGL WILL BE POSSIBLE IN THE HYS AREA. NORTHWESTERLY WINDS
AT 10 TO 15 KNOTS WILL CONTINUE OVERNIGHT AND BY LATE MORNING
DECREASE TO AROUND 10 KNOTS. THESE NORTHWESTERLY WINDS WILL THEN
GRADUALLY VEER TO THE NORTHEAST DURING THE AFTERNOON AS A WEAK
SURFACE BOUNDARY MOVES ACROSS WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 61 44 58 / 10 30 50 50
GCK 49 57 44 57 / 20 40 50 50
EHA 48 66 44 55 / 10 50 70 70
LBL 50 67 45 57 / 10 40 60 60
HYS 46 57 42 60 / 10 20 30 30
P28 51 65 47 60 / 10 30 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...UMSCHEID
LONG TERM...GERARD
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1100 PM MDT FRI APR 24 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 201 PM MDT FRI APR 24 2015
AT 1PM MDT VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
SHOWED PARTLY TO MOSTLY CLOUDY SKIES FOR LOCATIONS ACROSS THE TRI
STATE AREA WEST OF HIGHWAY 83...WITH LOWER BROKEN TO OVERCAST
CONDITIONS EAST OF THE HIGHWAY AHEAD OF AN ADVANCING WARM FRONTAL
BOUNDARY. CUMULUS DEVELOPMENT WAS BEGINNING TO DEVELOP ON RADAR
AND SATELLITE IMAGERY ALONG A TROUGH/DRY LINE IN EASTERN COLORADO.
RAP AND WATER VAPOR IMAGERY SHOWED AN UPPER LEVEL SHORTWAVE TROUGH
BEGINNING TO TAKE A NEGATIVE TILT INTO THE CENTRAL AND SOUTHER
HIGH PLAINS.
THE LATEST HRRR GUIDANCE WAS SHOWING CONVECTIVE INITIATION AT
20Z...ALTHOUGH CELLS ARE ALREADY BEGINNING TO DEVELOP. NMM AND ARW
GUIDANCE IS ALSO A BIT BEHIND REALITY WITH HAVING CONVECTION DEVELOP
BETWEEN 21Z AND 00Z. 0-1 KM AND 0-3 KM HELICITY WAS NOT IMPRESSIVE
WITH WIDESPREAD VALUES UNDER 50 FOR THE FORECAST AREA...SO NOT
EXPECTING TORNADOES TO BE A WIDESPREAD THREAT THIS AFTERNOON WITH
DEVELOPING STORMS. HOWEVER...0-6 KM BULK SHEAR APPROACHING 35-40 KTS
ACROSS THE AREA IN COMBINATION WITH 1500 J/KG OF CAPE SUGGESTS A
LARGE HAIL THREAT. WITH DCAPE VALUES MOSTLY BETWEEN 400 AND 500
J/KG...ISOLATED SEVERE WIND GUSTS FROM STORMS IS POSSIBLE...BUT
EXPECTING THUNDERSTORMS THIS AFTERNOON TO PRIMARILY HAVE A LARGE
HAIL THREAT. STORMS WILL GET GOING BY MID AFTERNOON AND LAST THROUGH
THE EVENING.
CLOUD COVER WILL BE PRESENT LATE THIS EVENING DUE TO A STEADY STREAM
OF MOISTURE MOVING INTO THE FORECAST AREA...HOWEVER A SHORTWAVE
RIDGE ALOFT WILL BEGIN TO FORM ACROSS THE AREA AND BRING DRIER AIR
INTO THE AREA OVERNIGHT. LOW TEMPERATURES WILL BE SLIGHTLY WARMER
THAN NORMAL IN THE MID TO UPPER 40S.
DRY AND WARM CONDITIONS WILL BE PRESENT TOMORROW WITH THE SHORTWAVE
UPPER LEVEL RIDGE THAT WILL MOVE INTO THE AREA...ALTHOUGH DRY
WEATHER WILL BE SHORT LIVED AS ANOTHER TROUGH WITH A CUT OFF LOW
FEATURE MOVES INTO THE COLORADO FRONT RANGE AND BRINGS CHANCES FOR
SHOWERS AND THUNDERSTORMS. THERE ARE SOME LOCATIONS WITH CAPE VALUES
APPROACHING 700 J/KG AND 0-6 BULK SHEAR APPROACHING 35 KTS...HOWEVER
FORECAST AREAS IN MODELS DO NOT NECESSARILY LINE UP.
THEREFORE...NOT EXPECTING A WIDE SEVERE WEATHER THREAT SATURDAY
AFTERNOON...ALTHOUGH AN ISOLATED SEVERE THUNDERSTORM THREAT WILL
EXIST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 201 PM MDT FRI APR 24 2015
SATURDAY NIGHT-MONDAY...LARGE SCALE UPPER LOW CLOSES OFF JUST SOUTH
OF FOUR CORNERS REGION SATURDAY NIGHT AND MOVES ACROSS THE SOUTHERN
PLAINS THROUGH MONDAY NIGHT. A COLD FRONT WILL DROP SOUTH ACROSS THE
THE CWA LATE SATURDAY NIGHT AND SUNDAY AND STALL SOUTH AND WEST OF
OUR CWA. SOUTHERLY THEN EASTERLY FLOW WILL BRING VERY GOOD MOISTURE
ADVECTION INTO OUR CWA AS THIS UPPER LEVEL FEATURE MOVES EAST WITH
OVERRUNNING NORTH OF THE STALLED FRONTAL ZONE WHERE ELEVATED
FRONT/FRONTOGENETIC FORCING WILL BE IN PLACE. BETTER PRECIP
SIGNAL IS CURRENTLY SATURDAY NIGHT THROUGH SUNDAY ACROSS THE
WESTERN AND SOUTHWESTERN PART OF THE CWA...WHERE I CONTINUED TREND
OF RAISING POPS. IT STILL LOOKS LIKE WE COULD SEE LIGHT PRECIP
PERSIST AT LEAST THROUGH LATE SUNDAY NIGHT BEFORE DRIER AIR BEGINS
TO ADVECT SOUTH AND SUBSIDENCE BUILDS SOUTHWEST MONDAY.
IF CURRENT SIGNAL/TREND CONTINUE I COULD SEE RAISING POPS TO
CATEGORICAL LATE SATURDAY NIGHT/SUNDAY...AND TO LIKELY CATEGORY
SUNDAY NIGHT THROUGH MONDAY. WHILE 40KM GUIDANCE SHOWS QPF AS FAR
EAST AS NORTON/GRAHAM THROUGH THESE PERIODS...PATTERN TENDS TO FAVOR
AREAS CLOSER TO FRONTAL ZONE/HIGHER TERRAIN IN COLORADO...SO I
KEPT LOWERS POPS NORTHEAST/EAST. IN POST FRONTAL ENVIRONMENT WITH
THICK STRATUS/LIKELY PRECIPITATION HIGH TEMPS WILL BE COOLER AND I
CONTINUED THE TREND OF LOWER HIGHS ESPECIALLY SUNDAY WHEN HIGHS
MAY STRUGGLE TO REACH THE UPPER 40S IN SOME AREAS.
MONDAY NIGHT-FRIDAY...THERE IS A SECONDARY H3 JET ROTATING THROUGH
THE NORTHERN PLAINS BEHIND THE LARGE SCALE TROUGH...AND THIS COULD
BRING ANOTHER QUICK SHOT OF LIGHT SHOWERS....OTHERWISE LARGE SCALE
RIDGING WILL BRING DRY CONDITIONS AND A WARMING TREND BACK TO THE
REGION THROUGH THURSDAY. MUCH WARMER CONDITIONS ARE EXPECTED BY
NEXT FRIDAY (80S) AS LEE TROUGH STRENGTHENS. WHILE THERE ISN`T A
LOT OF AGREEMENT AT THIS RANGE THE PATTERN DOES SUPPORT POSSIBLE
AFTERNOON/EVENING THUNDERSTORM DEVELOPMENT IN THE HIGHER TERRAIN
IN COLORADO MOVING EAST INTO THE WESTERN PORTIONS OF OUR CWA...SO
SLIGHT CHANCE POPS WERE KEPT IN PLACE FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1100 PM MDT FRI APR 24 2015
KGLD...WEST-NORTHWEST WIND AROUND 10KTS AT TAF ISSUANCE EXPECTED
TO VEER TO THE NORTHWEST AT SIMILAR SPEEDS BY 15Z THEN NORTH NEAR
10KTS BY 19Z. WINDS CONTINUE TO VEER TO THE EAST UNDER 10KTS IN
THE 21Z-23Z TIMEFRAME AND CONTINUE THROUGH 03Z BEFORE INCREASING
AND START TO GUST IN THE 20-25KT RANGE BY 04Z. VFR CONDITIONS
EXPECTED FOR MOST OF THE PERIOD WITH THE ONLY CHANCE AT IFR/VLIFR
CONDITIONS AFTER 04Z AS SATURATED BOUNDARY LAYER MOVES IN FROM THE
EAST. THUNDERSTORMS POSSIBLE AFTER 03Z AS WELL.
KMCK...NORTHWEST WIND UNDER 10KTS AT TAF ISSUANCE EXPECTED TO VEER
TO THE NORTH-NORTHEAST AT SIMILAR SPEEDS BY 18Z THEN EAST AROUND
12KTS AROUND 03Z. AFTER 03Z WINDS INCREASE AND START TO GUST IN
THE 20-25KT RANGE FROM THE EAST. TOUGH FORECAST ON CIGS FROM TAF
ISSUANCE THROUGH 17Z THEN AGAIN AFTER 05Z. STRATUS AND IFR/VLIFR
CIGS JUST EAST OF THE TERMINAL AND LATEST MODEL GUIDANCE HINTS
THAT THIS AIRMASS REACHES OR NEARLY REACHES THE TERMINAL DURING
THE TIMELINES LISTED ABOVE. WILL GO WITH SCATTERED TO BROKEN DECK
AROUND 600` AT TAF ISSUANCE WITH A CEILING AT SIMILAR HEIGHTS
AROUND 10Z. THESE CONDITIONS EXPECTED THROUGH 13Z BEFORE MVFR CIGS
DEVELOP FROM 14Z-17Z. AFTER 05Z IFR/MVFR CIGS MOVE BACK IN FROM
THE NORTHEAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...DR
AVIATION...99
AREA FORECAST DISCUSSION
NWS JACKSON KY
411 AM EDT SAT APR 25 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT SAT APR 25 2015
AN ACTIVE PERIOD IS IN STORE...WITH EVENTS JUST BEGINNING TO
UNFOLD. AN AREA OF SHOWERS IS EXPECTED TO DEVELOP AND MOVE NE OVER
THE REGION THIS MORNING. HOWEVER...IT IS BEHIND SCHEDULE AS BASED
ON THE 00Z MODELS...WITH A CONVECTIVE SYSTEM OVER MS AND AL
POSSIBLY FOILING THE OUTCOME. THE LATEST HRRR MODEL SUGGESTS IT
WILL STILL HAPPEN...BUT MAY BE MORE FOCUSED ON OUR NORTHERN
COUNTIES.
ONCE THIS PASSES...IT WILL BE A WAITING GAME FOR ADDITIONAL
CONVECTION TO DEVELOP DURING THE AFTERNOON AND EVENING AS A STORM
SYSTEM APPROACHES FROM THE WEST...ALONG A FRONTAL BOUNDARY DRAPED
ACROSS OUR AREA. IT STILL APPEARS THERE WILL BE LARGE SURFACE
BASED INSTABILITY PRESENT IN OUR SOUTHWEST COUNTIES...WITH WEAKER
AND MORE ELEVATED INSTABILITY FURTHER NORTHEAST. SHEAR WILL BE
MORE THAN SUFFICIENT TO SUPPORT ORGANIZED CONVECTION. DRY MID
LEVEL AIR IS ALSO EXPECTED IN OUR SW. THIS WILL PRESENT A THREAT
OF SEVERE WEATHER OVER OUR SW...WITH SUPER CELLS POSSIBLY
PRODUCING LARGE HAIL AND HIGH WINDS...AND A SECONDARY THREAT OF
TORNADOES. EXCESSIVE RAINFALL IS ALSO A CONCERN WITH TRAINING OF
CELLS ALONG THE FRONTAL BOUNDARY. WHERE THIS MAY SET UP IS STILL
UNCERTAIN. ANY HYDRO PROBLEMS LIKELY WOULD NOT ARISE UNTIL THIS
EVENING...AND HAVE OPTED TO LET DAY SHIFT EXAMINE THE 12Z RUN
BEFORE MAKING A DECISION ON A FFA.
THE FRONTAL BOUNDARY WILL MOVE TO OUR SOUTH AS LOW PRESSURE MOVES
EAST THROUGH THE REGION TONIGHT. ANY LINGERING SHOWERS WILL END ON
SUNDAY MORNING AND CLOUDS WILL BREAK UP DURING THE DAY FROM NW TO
SE AS DRY AIR MOVES IN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 AM EDT SAT APR 25 2015
THE MODELS WERE IN GOOD AGREEMENT IN THE EXTENDED. THE PERIOD IS
SET TO BEGIN WITH A LARGE RIDGE OF HIGH PRESSURE MOVE OUT OF THE
NORTH CENTRAL PLAINS AND ACROSS THE LOWER GREAT LAKES AND OHIO AND
TENNESSEE VALLEY REGIONS SUNDAY NIGHT THROUGH TUESDAY. THE PATTERN
IS THEN FORECAST TO CHANGE TUESDAY NIGHT AND WEDNESDAY...AS BOTH
NORTHERN AND SOUTHERN STREAM WEATHER SYSTEMS MAKE THEIR WAY ACROSS
THE GREAT LAKES AND GULF COAST REGIONS. THE SOUTHERN STREAM SYSTEM
APPEARS TO BE THE STRONGER OF THE TWO...AND THEREFORE WOULD HAVE
TO GREATER INFLUENCE ON AREA WEATHER MID WEEK. AS IT STANDS...A
ROUGHLY 60 40 BLEND OF THE ECMWF AND GFS MODELS WAS USED TO CREATE
THE FORECAST FROM TUESDAY NIGHT ONWARD. THE SOUTHERN STREAM
TROUGH IS PROGGED TO BRING MOISTURE OFF THE GULF OF MEXICO
NORTHWARD INTO CENTRAL AND EASTERN KENTUCKY WEDNESDAY AND
WEDNESDAY NIGHT. AS THIS OCCURS...THE NORTHERN STREAM SYSTEM IS
FORECAST TO DIVE SOUTHWARD AND PHASE WITH THE TENNESSEE VALLEY
SOUTHEASTERN CONUS LOW. THE GFS DOES DIFFER SLIGHTLY FROM THE
ECMWF MODEL DURING THIS PERIOD...AS ITS NORTHERN STREAM LOW PUSHES
ON EASTWARD INTO NEW ENGLAND...AS OPPOSED TO PHASING WITH THE
SOUTHERN SYSTEM...AS THE ECMWF IS DEPICTING. THAT BEING
SAID...THIS IS WHERE THE USUALLY MORE CONSISTENT ECMWF MODEL
SOLUTION WAS FAVORED. THERE WILL BE A CHANCE OF RAIN IN THE
FORECAST FOR THE ENTIRE AREA FROM LATE TUESDAY NIGHT THROUGH
THURSDAY NIGHT. HOWEVER...DUE TO THE DIFFERING MODEL
SOLUTIONS...DECIDED TO STAY WITH SLIGHT CHANCE TO CHANCE
POPS...WITH 40 BEING THE HIGH END DURING THE WET PERIOD. FRIDAY
AND FRIDAY NIGHT LOOK TO BE DRY AS THE SOUTHERN STREAM WEATHER
SYSTEM EXITS TO OUR EAST AND ANOTHER RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE SOUTHERN AND SOUTHEASTERN CONUS.
TEMPERATURES NEXT WEEK WILL LIKELY BE BELOW NORMAL THROUGH
THURSDAY...DUE TO THE INFLUENCE OF CLOUD COVER AND PRECIPITATION
AND THE FACT THAT THIS WEEKENDS TEMPERATURES WILL ALSO REMAIN WELL
BELOW NORMAL DUE WIDESPREAD CLOUD COVER AND PRECIPITATION. WHAT
THIS AMOUNTS TO IS THE ATMOSPHERE WILL STARTING OFF BEHIND THE
EIGHT BALL TO START THE WEEK TEMPERATURE WISE...MAKING IT
DIFFICULT FOR THINGS TO WARM UP AS MUCH AS NORMAL DUE TO THE SHORT
BREAK BETWEEN WEATHER SYSTEMS. HIGHS ON FRIDAY SHOULD BE RIGHT
AROUND NORMAL ACROSS THE ENTIRE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 202 AM EDT SAT APR 25 2015
VFR CONDITIONS WERE PRESENT AT TAF ISSUANCE...BUT WILL DEGRADE TO
MVFR FROM SW TO NE BETWEEN ABOUT 06Z AND 14Z AS RAIN DEVELOPS. IFR
IS ALSO EXPECTED AT TIMES THROUGH EARLY AFTERNOON. STEADY
PRECIPITATION WILL TAPER OFF FROM SW TO NE DURING THE LATE MORNING
AND EARLY AFTERNOON...AND WILL BE REPLACED BY SCATTERED SHOWERS
AND THUNDERSTORMS. THEY WILL BECOME MORE NUMEROUS LATE IN THE DAY
AND THIS EVENING. SOME LOCATIONS MAY DESCEND BACK TO IFR WITH THE
SHOWERS AND STORMS THIS EVENING. SOME OF THESE STORMS COULD
PRODUCE HAIL AND HIGH WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HAL
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
400 AM EDT SAT APR 25 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 400 AM EDT SAT APR 25 2015
AN ACTIVE PERIOD IS IN STORE...WITH EVENTS JUST BEGINNING TO
UNFOLD. AN AREA OF SHOWERS IS EXPECTED TO DEVELOP AND MOVE NE OVER
THE REGION THIS MORNING. HOWEVER...IT IS BEHIND SCHEDULE AS BASED
ON THE 00Z MODELS...WITH A CONVECTIVE SYSTEM OVER MS AND AL
POSSIBLY FOILING THE OUTCOME. THE LATEST HRRR MODEL SUGGESTS IT
WILL STILL HAPPEN...BUT MAY BE MORE FOCUSE ON OUR NORTHERN
COUNTIES.
ONCE THIS PASSES...IT WILL BE A WAITING GAME FOR ADDITIONAL
CONVECTION TO DEVELOP DURING THE AFTERNOON AND EVENING AS A STORM
SYSTEM APPROACHES FROM THE WEST...ALONG A FRONTAL BOUNDARY DRAPED
ACROSS OUR AREA. IT STILL APPEARS THERE WILL BE LARGE SURFACE
BASED INSTABILITY PRESENT IN OUR SOUTHWEST COUNTIES...WITH WEAKER
AND MORE ELEVATED INSTABILITY FURTHER NORTHEAST. SHEAR WILL BE
MORE THAN SUFFICIENT TO SUPPORT ORGANIZED CONVECTION. DRY MID
LEVEL AIR IS ALSO EXPECTED IN OUR SW. THIS WILL PRESENT A THREAT
OF SEVERE WEATHER.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 AM EDT SAT APR 25 2015
THE MODELS WERE IN GOOD AGREEMENT IN THE EXTENDED. THE PERIOD IS
SET TO BEGIN WITH A LARGE RIDGE OF HIGH PRESSURE MOVE OUT OF THE
NORTH CENTRAL PLAINS AND ACROSS THE LOWER GREAT LAKES AND OHIO AND
TENNESSEE VALLEY REGIONS SUNDAY NIGHT THROUGH TUESDAY. THE PATTERN
IS THEN FORECAST TO CHANGE TUESDAY NIGHT AND WEDNESDAY...AS BOTH
NORTHERN AND SOUTHERN STREAM WEATHER SYSTEMS MAKE THEIR WAY ACROSS
THE GREAT LAKES AND GULF COAST REGIONS. THE SOUTHERN STREAM SYSTEM
APPEARS TO BE THE STRONGER OF THE TWO...AND THEREFORE WOULD HAVE
TO GREATER INFLUENCE ON AREA WEATHER MID WEEK. AS IT STANDS...A
ROUGHLY 60 40 BLEND OF THE ECMWF AND GFS MODELS WAS USED TO CREATE
THE FORECAST FROM TUESDAY NIGHT ONWARD. THE SOUTHERN STREAM
TROUGH IS PROGGED TO BRING MOISTURE OFF THE GULF OF MEXICO
NORTHWARD INTO CENTRAL AND EASTERN KENTUCKY WEDNESDAY AND
WEDNESDAY NIGHT. AS THIS OCCURS...THE NORTHERN STREAM SYSTEM IS
FORECAST TO DIVE SOUTHWARD AND PHASE WITH THE TENNESSEE VALLEY
SOUTHEASTERN CONUS LOW. THE GFS DOES DIFFER SLIGHTLY FROM THE
ECMWF MODEL DURING THIS PERIOD...AS ITS NORTHERN STREAM LOW PUSHES
ON EASTWARD INTO NEW ENGLAND...AS OPPOSED TO PHASING WITH THE
SOUTHERN SYSTEM...AS THE ECMWF IS DEPICTING. THAT BEING
SAID...THIS IS WHERE THE USUALLY MORE CONSISTENT ECMWF MODEL
SOLUTION WAS FAVORED. THERE WILL BE A CHANCE OF RAIN IN THE
FORECAST FOR THE ENTIRE AREA FROM LATE TUESDAY NIGHT THROUGH
THURSDAY NIGHT. HOWEVER...DUE TO THE DIFFERING MODEL
SOLUTIONS...DECIDED TO STAY WITH SLIGHT CHANCE TO CHANCE
POPS...WITH 40 BEING THE HIGH END DURING THE WET PERIOD. FRIDAY
AND FRIDAY NIGHT LOOK TO BE DRY AS THE SOUTHERN STREAM WEATHER
SYSTEM EXITS TO OUR EAST AND ANOTHER RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE SOUTHERN AND SOUTHEASTERN CONUS.
TEMPERATURES NEXT WEEK WILL LIKELY BE BELOW NORMAL THROUGH
THURSDAY...DUE TO THE INFLUENCE OF CLOUD COVER AND PRECIPITATION
AND THE FACT THAT THIS WEEKENDS TEMPERATURES WILL ALSO REMAIN WELLBELOW
NORMAL DUE WIDESPREAD CLOUD COVER AND PRECIPITATION. WHAT THIS
AMOUNTS TO IS THE ATMOSPHERE WILL STARTING OFF BEHIND THE EIGHT
BALL TO START THE WEEK TEMPERATURE WISE...MAKING IT DIFFICULT FOR
THINGS TO WARM UP AS MUCH AS NORMAL DUE TO THE SHORT BREAK BETWEEN
WEATHER SYSTEMS. HIGHS ON FRIDAY SHOULD BE RIGHT AROUND NORMAL
ACROSS THE ENTIRE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 202 AM EDT SAT APR 25 2015
VFR CONDITIONS WERE PRESENT AT TAF ISSUANCE...BUT WILL DEGRADE TO
MVFR FROM SW TO NE BETWEEN ABOUT 06Z AND 14Z AS RAIN DEVELOPS. IFR
IS ALSO EXPECTED AT TIMES THROUGH EARLY AFTERNOON. STEADY
PRECIPITATION WILL TAPER OFF FROM SW TO NE DURING THE LATE MORNING
AND EARLY AFTERNOON...AND WILL BE REPLACED BY SCATTERED SHOWERS
AND THUNDERSTORMS. THEY WILL BECOME MORE NUMEROUS LATE IN THE DAY
AND THIS EVENING. SOME LOCATIONS MAY DESCEND BACK TO IFR WITH THE
SHOWERS AND STORMS THIS EVENING. SOME OF THESE STORMS COULD
PRODUCE HAIL AND HIGH WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HAL
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
335 AM EDT SAT APR 25 2015
.UPDATE...
ISSUED AT 202 AM EDT SAT APR 25 2015
WITH EXTENSIVE CLOUD COVER IN PLACE...TEMPS HAVE NOT DROPPED OFF
AS QUICKLY AS WAS FORECAST. HAVE RAISED OVERNIGHT FORECAST MIN
TEMPS A BIT...ESPECIALLY IN EASTERN VALLEYS.
UPDATE ISSUED AT 1050 PM EDT FRI APR 24 2015
DID AN UPDATE TO FINE TUNE THE POPS AND WX THROUGH THE REST OF THE
NIGHT BASED ON THE NEWEST HRRR AND NAM12 GUIDANCE AS WELL AS
CURRENT RADAR/OBS. ALSO MATCHED UP THE HOURLY T AND TD GRIDS PER
THE LATEST OBS AND TRENDS...WHERE A 5 DEGREE OR SO RIDGE TO VALLEY
SPLIT CURRENTLY EXISTS IN THE EAST. THESE GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS...ALONG WITH THE ISSUANCE OF A FRESHENED
SET OF ZONES.
UPDATE ISSUED AT 745 PM EDT FRI APR 24 2015
23Z SFC ANALYSIS SHOWS HIGH PRESSURE CLINGING ON IN THE FAR EAST
IN THE FACE OF AN APPROACHING AREA OF LOW PRESSURE...POISED TO
BRING SVR WX TO KY LATER ON SATURDAY...FROM THE WEST. THIS
WESTERN LOW/S WARM FRONT WILL SWING TOWARD THE AREA BY DAWN...
AFFECTING THE FAR SOUTHWEST INITIALLY THEN LIFTING DEEPER INTO
EAST KENTUCKY THROUGH MIDDAY SATURDAY. THE PCPN WILL HAVE A TOUGH
TIME REACHING THE GROUND ACROSS THE AREA THROUGH THE BULK OF THE
NIGHT AS THE VERY DRY LOWER ATMOSPHERE ONLY SLOWLY SATURATES...
DESPITE THE HRRR/NAM12 INDICATIONS. IN THIS ENVIRONMENT...EXPECT
THE EASTERN VALLEYS TO DROP OFF QUICKLY FOLLOWING SUNSET...EVEN
WITH THE THIN HIGH CLOUDS NOW IN PLACE OVERHEAD. ELSEWHERE...
TEMPERATURES WILL STAY UP THROUGH THE NIGHT...MUCH WARMER THAN
LAST NIGHT. HAVE UPDATED THE FORECAST TO NUDGE TEMPS IN THE
EASTERN VALLEYS DOWN A BIT...BUT EXPECT THEM TO MIX OUT BY DAWN AS
THE AIR SATURATES AND SHOWERS PUSH OVER THIS PART OF THE STATE. IN
ADDITION TO THE SEVERE THREAT FOR SATURDAY...THE LATEST MODEL RUNS
CONTINUE TO INDICATE THAT THERE IS ALSO A POTENTIAL FOR EXCESSIVE
RAINFALL DEPENDING ON THE TRACKS OF THE INDIVIDUAL CELLS AND/OR AN
MCS TRACKING ACROSS THE CWA IN THE AFTERNOON/EVENING THAT
CERTAINLY LOOKS POSSIBLE. THESE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI APR 24 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SURFACE HIGH PRESSURE
SLOWLY SLIDING OFF TO THE EAST TODAY. MID AND UPPER LEVEL CLOUD
COVER AT THIS TIME IS BEGINNING TO STREAM INTO EASTERN KENTUCKY
THIS EVENING. THIS IS AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
OUT WEST OVER THE CENTRAL PLAINS. CLOUD COVER OVER THE AREA WILL
LIKELY KEEP TEMPERATURES OVERNIGHT NEARLY UNIFORM WITH SOUTHERLY
WARM AIR MOVING INTO THE AREA THROUGH THE NIGHT. AT THIS TIME
OVERNIGHT...THE SURFACE LOW SLIDES EAST AS A WARM FRONT DEVELOPS
IN THE LOWER MS VALLEY AND MOVING NORTHEAST. THIS WILL BRING
SHOWERS INTO EASTERN KENTUCKY BY MIDNIGHT OR SHORTLY AFTERWARD.
HEADING INTO THE PREDAWN HOURS SATURDAY MORNING...THE MAIN SURFACE
LOW BEGINS TO MOVE INTO THE MID MS RIVER VALLEY AND INTO THE
MIDWEST WITH SOME INSTABILITY BEGINNING TO ENTER THE SOUTHWESTERN
COUNTIES AND THIS MAY LEAD TO A FEW EARLY NON SEVERE STORMS AND
MAY NEED TO ADD THUNDER TO THE TONIGHT PERIOD OF THE HWO. HEADING
INTO THE DAY ON SATURDAY...AFTER EARLIER RAINFALL HAS MOVED
THROUGH...SOME CLEARING SKIES AND RECOVERING ENERGY AND
DESTABILIZATION WILL THEN OCCUR WITH MOST UNSTABLE CAPE AROUND
1000 TO 1500 J/KG OVER SOUTHEASTERN KENTUCKY BY THE 18Z TIME
FRAME. THIS ALSO WITH SOME 60 KNOT SFC TO 6KM BULK SHEAR WILL BE
ENOUGH FOR SOME ROTATING STORMS TOMORROW AFTERNOON. DUE TO THIS
THREAT SPC HAS PUT THE SOUTHERN AREA IN AN ENHANCED THREAT OF
SEVERE WEATHER AND HAVE PUT THIS THREAT IN THE HWO AND MAY NEED AN
SPS TO HIGHLIGHT THE THREAT IN DETAIL. THE ONLY THREAT THAT IS A
BIT QUESTIONABLE TOMORROW WILL BE THE FLASH FLOOD THREAT. THOUGH
THE LAST HEAVY RAINFALL WAS LONG ENOUGH AGO THAT MOST PLACES HAVE
BEEN ALLOWED TO DRAIN AND DRY OUT. AS WELL...GREEN HAS GONE INTO
FULL SWING ACROSS THE AREA ALLEVIATING THE RUNOFF POTENTIAL.
HOWEVER...THE DISCRETE SUPER CELL POTENTIAL WILL ADD TO THE THREAT
OF FLASH FLOODING AS WELL AS IF AN MCS DEVELOPS BY LATE IN THE
EVENING ON SATURDAY. MAY NEED TO EVALUATE THIS DURING THE NEXT
MODEL RUN.
HEADING INTO SATURDAY EVENING...THE WARM FRONT MOVES THROUGH TO
THE NORTHEAST AND THEN THE SURFACE LOW TRACKS RIGHT ACROSS EASTERN
KENTUCKY WITH ANOTHER STRONG SHOT OF RAINFALL WHICH MAY BE ENOUGH
TO INITIATE THE FLASH FLOOD THREAT. HAVE ADJUSTED THE QPF FOR THE
00Z TO 06Z SUNDAY NIGHT PERIOD FOR THIS RAINFALL. RAINFALL AMOUNTS
WILL BE LESSENING BY 06Z TO 12Z RANGE SUNDAY NIGHT AS THE EVENT
WILL BE WINDING DOWN. FOR NOW...WILL HIGHLIGHT THE SEVERE AND
FLOOD THREAT IN THE HWO AND MAY NEED AN SPS TO FURTHER HIGHLIGHT
THIS. THE ZFP WILL HAVE SEVERE POTENTIAL AND HEAVY RAINFALL
MENTIONED AS WELL.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 AM EDT SAT APR 25 2015
THE MODELS WERE IN GOOD AGREEMENT IN THE EXTENDED. THE PERIOD IS
SET TO BEGIN WITH A LARGE RIDGE OF HIGH PRESSURE MOVE OUT OF THE
NORTH CENTRAL PLAINS AND ACROSS THE LOWER GREAT LAKES AND OHIO AND
TENNESSEE VALLEY REGIONS SUNDAY NIGHT THROUGH TUESDAY. THE PATTERN
IS THEN FORECAST TO CHANGE TUESDAY NIGHT AND WEDNESDAY...AS BOTH
NORTHERN AND SOUTHERN STREAM WEATHER SYSTEMS MAKE THEIR WAY ACROSS
THE GREAT LAKES AND GULF COAST REGIONS. THE SOUTHERN STREAM SYSTEM
APPEARS TO BE THE STRONGER OF THE TWO...AND THEREFORE WOULD HAVE
TO GREATER INFLUENCE ON AREA WEATHER MID WEEK. AS IT STANDS...A
ROUGHLY 60 40 BLEND OF THE ECMWF AND GFS MODELS WAS USED TO CREATE
THE FORECAST FROM TUESDAY NIGHT ONWARD. THE SOUTHERN STREAM
TROUGH IS PROGGED TO BRING MOISTURE OFF THE GULF OF MEXICO
NORTHWARD INTO CENTRAL AND EASTERN KENTUCKY WEDNESDAY AND
WEDNESDAY NIGHT. AS THIS OCCURS...THE NORTHERN STREAM SYSTEM IS
FORECAST TO DIVE SOUTHWARD AND PHASE WITH THE TENNESSEE VALLEY
SOUTHEASTERN CONUS LOW. THE GFS DOES DIFFER SLIGHTLY FROM THE
ECMWF MODEL DURING THIS PERIOD...AS ITS NORTHERN STREAM LOW PUSHES
ON EASTWARD INTO NEW ENGLAND...AS OPPOSED TO PHASING WITH THE
SOUTHERN SYSTEM...AS THE ECMWF IS DEPICTING. THAT BEING
SAID...THIS IS WHERE THE USUALLY MORE CONSISTENT ECMWF MODEL
SOLUTION WAS FAVORED. THERE WILL BE A CHANCE OF RAIN IN THE
FORECAST FOR THE ENTIRE AREA FROM LATE TUESDAY NIGHT THROUGH
THURSDAY NIGHT. HOWEVER...DUE TO THE DIFFERING MODEL
SOLUTIONS...DECIDED TO STAY WITH SLIGHT CHANCE TO CHANCE
POPS...WITH 40 BEING THE HIGH END DURING THE WET PERIOD. FRIDAY
AND FRIDAY NIGHT LOOK TO BE DRY AS THE SOUTHERN STREAM WEATHER
SYSTEM EXITS TO OUR EAST AND ANOTHER RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE SOUTHERN AND SOUTHEASTERN CONUS.
TEMPERATURES NEXT WEEK WILL LIKELY BE BELOW NORMAL THROUGH
THURSDAY...DUE TO THE INFLUENCE OF CLOUD COVER AND PRECIPITATION
AND THE FACT THAT THIS WEEKENDS TEMPERATURES WILL ALSO REMAIN WELLBELOW
NORMAL DUE WIDESPREAD CLOUD COVER AND PRECIPITATION. WHAT THIS
AMOUNTS TO IS THE ATMOSPHERE WILL STARTING OFF BEHIND THE EIGHT
BALL TO START THE WEEK TEMPERATURE WISE...MAKING IT DIFFICULT FOR
THINGS TO WARM UP AS MUCH AS NORMAL DUE TO THE SHORT BREAK BETWEEN
WEATHER SYSTEMS. HIGHS ON FRIDAY SHOULD BE RIGHT AROUND NORMAL
ACROSS THE ENTIRE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 202 AM EDT SAT APR 25 2015
VFR CONDITIONS WERE PRESENT AT TAF ISSUANCE...BUT WILL DEGRADE TO
MVFR FROM SW TO NE BETWEEN ABOUT 06Z AND 14Z AS RAIN DEVELOPS. IFR
IS ALSO EXPECTED AT TIMES THROUGH EARLY AFTERNOON. STEADY
PRECIPITATION WILL TAPER OFF FROM SW TO NE DURING THE LATE MORNING
AND EARLY AFTERNOON...AND WILL BE REPLACED BY SCATTERED SHOWERS
AND THUNDERSTORMS. THEY WILL BECOME MORE NUMEROUS LATE IN THE DAY
AND THIS EVENING. SOME LOCATIONS MAY DESCEND BACK TO IFR WITH THE
SHOWERS AND STORMS THIS EVENING. SOME OF THESE STORMS COULD
PRODUCE HAIL AND HIGH WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
202 AM EDT SAT APR 25 2015
.UPDATE...
ISSUED AT 202 AM EDT SAT APR 25 2015
WITH EXTENSIVE CLOUD COVER IN PLACE...TEMPS HAVE NOT DROPPED OFF
AS QUICKLY AS WAS FORECAST. HAVE RAISED OVERNIGHT FORECAST MIN
TEMPS A BIT...ESPECIALLY IN EASTERN VALLEYS.
UPDATE ISSUED AT 1050 PM EDT FRI APR 24 2015
DID AN UPDATE TO FINE TUNE THE POPS AND WX THROUGH THE REST OF THE
NIGHT BASED ON THE NEWEST HRRR AND NAM12 GUIDANCE AS WELL AS
CURRENT RADAR/OBS. ALSO MATCHED UP THE HOURLY T AND TD GRIDS PER
THE LATEST OBS AND TRENDS...WHERE A 5 DEGREE OR SO RIDGE TO VALLEY
SPLIT CURRENTLY EXISTS IN THE EAST. THESE GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS...ALONG WITH THE ISSUANCE OF A FRESHENED
SET OF ZONES.
UPDATE ISSUED AT 745 PM EDT FRI APR 24 2015
23Z SFC ANALYSIS SHOWS HIGH PRESSURE CLINGING ON IN THE FAR EAST
IN THE FACE OF AN APPROACHING AREA OF LOW PRESSURE...POISED TO
BRING SVR WX TO KY LATER ON SATURDAY...FROM THE WEST. THIS
WESTERN LOW/S WARM FRONT WILL SWING TOWARD THE AREA BY DAWN...
AFFECTING THE FAR SOUTHWEST INITIALLY THEN LIFTING DEEPER INTO
EAST KENTUCKY THROUGH MIDDAY SATURDAY. THE PCPN WILL HAVE A TOUGH
TIME REACHING THE GROUND ACROSS THE AREA THROUGH THE BULK OF THE
NIGHT AS THE VERY DRY LOWER ATMOSPHERE ONLY SLOWLY SATURATES...
DESPITE THE HRRR/NAM12 INDICATIONS. IN THIS ENVIRONMENT...EXPECT
THE EASTERN VALLEYS TO DROP OFF QUICKLY FOLLOWING SUNSET...EVEN
WITH THE THIN HIGH CLOUDS NOW IN PLACE OVERHEAD. ELSEWHERE...
TEMPERATURES WILL STAY UP THROUGH THE NIGHT...MUCH WARMER THAN
LAST NIGHT. HAVE UPDATED THE FORECAST TO NUDGE TEMPS IN THE
EASTERN VALLEYS DOWN A BIT...BUT EXPECT THEM TO MIX OUT BY DAWN AS
THE AIR SATURATES AND SHOWERS PUSH OVER THIS PART OF THE STATE. IN
ADDITION TO THE SEVERE THREAT FOR SATURDAY...THE LATEST MODEL RUNS
CONTINUE TO INDICATE THAT THERE IS ALSO A POTENTIAL FOR EXCESSIVE
RAINFALL DEPENDING ON THE TRACKS OF THE INDIVIDUAL CELLS AND/OR AN
MCS TRACKING ACROSS THE CWA IN THE AFTERNOON/EVENING THAT
CERTAINLY LOOKS POSSIBLE. THESE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI APR 24 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE SURFACE HIGH PRESSURE
SLOWLY SLIDING OFF TO THE EAST TODAY. MID AND UPPER LEVEL CLOUD
COVER AT THIS TIME IS BEGINNING TO STREAM INTO EASTERN KENTUCKY
THIS EVENING. THIS IS AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
OUT WEST OVER THE CENTRAL PLAINS. CLOUD COVER OVER THE AREA WILL
LIKELY KEEP TEMPERATURES OVERNIGHT NEARLY UNIFORM WITH SOUTHERLY
WARM AIR MOVING INTO THE AREA THROUGH THE NIGHT. AT THIS TIME
OVERNIGHT...THE SURFACE LOW SLIDES EAST AS A WARM FRONT DEVELOPS
IN THE LOWER MS VALLEY AND MOVING NORTHEAST. THIS WILL BRING
SHOWERS INTO EASTERN KENTUCKY BY MIDNIGHT OR SHORTLY AFTERWARD.
HEADING INTO THE PREDAWN HOURS SATURDAY MORNING...THE MAIN SURFACE
LOW BEGINS TO MOVE INTO THE MID MS RIVER VALLEY AND INTO THE
MIDWEST WITH SOME INSTABILITY BEGINNING TO ENTER THE SOUTHWESTERN
COUNTIES AND THIS MAY LEAD TO A FEW EARLY NON SEVERE STORMS AND
MAY NEED TO ADD THUNDER TO THE TONIGHT PERIOD OF THE HWO. HEADING
INTO THE DAY ON SATURDAY...AFTER EARLIER RAINFALL HAS MOVED
THROUGH...SOME CLEARING SKIES AND RECOVERING ENERGY AND
DESTABILIZATION WILL THEN OCCUR WITH MOST UNSTABLE CAPE AROUND
1000 TO 1500 J/KG OVER SOUTHEASTERN KENTUCKY BY THE 18Z TIME
FRAME. THIS ALSO WITH SOME 60 KNOT SFC TO 6KM BULK SHEAR WILL BE
ENOUGH FOR SOME ROTATING STORMS TOMORROW AFTERNOON. DUE TO THIS
THREAT SPC HAS PUT THE SOUTHERN AREA IN AN ENHANCED THREAT OF
SEVERE WEATHER AND HAVE PUT THIS THREAT IN THE HWO AND MAY NEED AN
SPS TO HIGHLIGHT THE THREAT IN DETAIL. THE ONLY THREAT THAT IS A
BIT QUESTIONABLE TOMORROW WILL BE THE FLASH FLOOD THREAT. THOUGH
THE LAST HEAVY RAINFALL WAS LONG ENOUGH AGO THAT MOST PLACES HAVE
BEEN ALLOWED TO DRAIN AND DRY OUT. AS WELL...GREEN HAS GONE INTO
FULL SWING ACROSS THE AREA ALLEVIATING THE RUNOFF POTENTIAL.
HOWEVER...THE DISCRETE SUPER CELL POTENTIAL WILL ADD TO THE THREAT
OF FLASH FLOODING AS WELL AS IF AN MCS DEVELOPS BY LATE IN THE
EVENING ON SATURDAY. MAY NEED TO EVALUATE THIS DURING THE NEXT
MODEL RUN.
HEADING INTO SATURDAY EVENING...THE WARM FRONT MOVES THROUGH TO
THE NORTHEAST AND THEN THE SURFACE LOW TRACKS RIGHT ACROSS EASTERN
KENTUCKY WITH ANOTHER STRONG SHOT OF RAINFALL WHICH MAY BE ENOUGH
TO INITIATE THE FLASH FLOOD THREAT. HAVE ADJUSTED THE QPF FOR THE
00Z TO 06Z SUNDAY NIGHT PERIOD FOR THIS RAINFALL. RAINFALL AMOUNTS
WILL BE LESSENING BY 06Z TO 12Z RANGE SUNDAY NIGHT AS THE EVENT
WILL BE WINDING DOWN. FOR NOW...WILL HIGHLIGHT THE SEVERE AND
FLOOD THREAT IN THE HWO AND MAY NEED AN SPS TO FURTHER HIGHLIGHT
THIS. THE ZFP WILL HAVE SEVERE POTENTIAL AND HEAVY RAINFALL
MENTIONED AS WELL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 PM EDT FRI APR 24 2015
ANY REMAINING RAINFALL SHOULD BE WINDING DOWN BY SUNDAY MORNING AS
THE SFC LOW AND TRAILING COLD FRONT PUSH EAST OF KY. BEHIND THIS...
SKIES WILL GRADUALLY CLEAR AS DRY AIR FILTERS INTO THE REGION SUNDAY
EVENING...ALLOWING FOR EASTERN KENTUCKY TO RECEIVE A BREAK FROM THE
WET WEATHER TO START THE WORK WEEK. THIS IS DUE TO AN AREA OF HIGH
PRESSURE FORECAST TO MOVE SLOWLY ACROSS THE OH AND TN VALLEYS MONDAY
AND TUESDAY.
A LARGE CUTOFF LOW WILL THEN GRADUALLY MOVE EWD FROM TX ACROSS THE
SOUTHEASTERN US WEDNESDAY THROUGH THURSDAY. AS THE LOW MOVES EWD ITS
ENERGY IS FORECASTED TO GET WRAPPED INTO A DEEPENING NORTHERN STREAM
TROUGH. THE MODELS HAVE COME INTO BETTER AGREEMENT IN THE PAST
COUPLE OF RUNS WITH THE EVOLUTION OF THIS SYSTEM...WHERE THE ECMWF
SOLUTION HAS THE AREA OF LOW PRESSURE MOVING ALONG A TRACK SIMILAR
TO THAT OF THE GFS. HOWEVER...THE ECMWF SOLUTION KEEPS THE LOW CUT
OFF AND SEPARATE FROM THE NORTHERN STREAM TROUGH...CREATING QUITE A
BIT MORE PRECIP THAN THE GFS ACROSS EASTERN KENTUCKY THROUGH THE END
OF THE WORK WEEK. WITH UNCERTAINTY STILL EXISTING IN THIS PART OF
THE EXTENDED...DECIDED TO KEEP PRECIP IN DURING THE WED/THURS TIME
FRAME...AND STUCK CLOSE TO THE CR SUPERBLEND.
TEMPERATURES WILL GENERALLY BE BELOW NORMAL AND STAY IN THE 60S FOR
HIGHS AND IN THE 40S FOR LOWS THROUGHOUT THE EXTENDED. DURING THE
DRIER PERIODS...TEMPS WILL BE CLOSER TO NORMAL VALUES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 202 AM EDT SAT APR 25 2015
VFR CONDITIONS WERE PRESENT AT TAF ISSUANCE...BUT WILL DEGRADE TO
MVFR FROM SW TO NE BETWEEN ABOUT 06Z AND 14Z AS RAIN DEVELOPS. IFR
IS ALSO EXPECTED AT TIMES THROUGH EARLY AFTERNOON. STEADY
PRECIPITATION WILL TAPER OFF FROM SW TO NE DURING THE LATE MORNING
AND EARLY AFTERNOON...AND WILL BE REPLACED BY SCATTERED SHOWERS
AND THUNDERSTORMS. THEY WILL BECOME MORE NUMEROUS LATE IN THE DAY
AND THIS EVENING. SOME LOCATIONS MAY DESCEND BACK TO IFR WITH THE
SHOWERS AND STORMS THIS EVENING. SOME OF THESE STORMS COULD
PRODUCE HAIL AND HIGH WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...SHALLENBERGER
LONG TERM...JVM
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1153 PM CDT FRI APR 24 2015
.AVIATION...SOUPY AIRMASS WITH ABUNDANT MOISTURE. SOME SHOWERS
STREAMING INTO THE BPT AND LCH TERMINAL AREAS. CIGS HAVE ALREADY
LOWERED TO IFR AT BPT, ARA, AND AEX. BAND OF TSTMS SHOWING SIGNS
OF WEAKENING AND SLOWING NORTHWEST OF AEX. WILL INCLUDE VCTS LATE
TNITE THERE. REMAINDER OF TERMINALS WILL HEAD FOR LIFR TNITE. WILL
GO WITH MVFR MOST OF THE DAY ON SATURDAY IFR BCMG LIFR SATURDAY
EVENING.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 950 PM CDT FRI APR 24 2015/
DISCUSSION...
SFC OBS FROM AROUND THE REGION SHOW THE ENTIRE FORECAST AREA IN A
SIGNIFICANT WARM SECTOR WITH DEWPOINTS RUNNING IN THE LOWER/MID
70S MOST LOCATIONS AS OF 02Z. 00Z KLCH SOUNDING SHOWED AN AIRMASS
PRIMED FOR CONVECTION WITH A PWAT VALUE RUNNING ABOUT 200 PERCENT
OF NORMAL...EXCELLENT INSTABILITY/LAPSE RATES/CAPE...AND GOOD
LOW-LEVEL SHEAR. WATER VAPOR IMAGERY SHOWS MULTIPLE DISTURBANCES
IN THE SRN STREAM FLOW ALOFT. ADD ALL THIS UP AND REGIONAL 88DS
CURRENTLY SHOW A FEW SHOWERS ONGOING ACROSS THE FORECAST AREA...
BUT A SIGNIFICANT SQUALL LINE/MCS CROSSING SRN AR/NWRN LA/NERN TX
ATTM. AS EXPECTED LATEST HRRR RUN HAS THIS EVENT PEGGED PRETTY
WELL AND IS IN LINE WITH INHERITED GRIDS/ZONES. LATEST SPC DAY 1
OUTLOOK HAS REDUCED OUR SEVERE RISK TO MARGINAL...BUT GIVEN SUCH
GOOD CONVECTIVE PARAMETERS NOTED EARLIER WILL MAINTAIN THE
INHERITED SEVERE MENTION. ELSEWHERE CHANGES WERE MINIMAL.
UPDATE OUT SHORTLY.
25
PREV DISCUSSION... /ISSUED 646 PM CDT FRI APR 24 2015/
AVIATION...THE SOUTHERN TERMINALS SHOULD HAVE MVFR CIGS LINGERING
THIS EVENING. TOWARDS MIDNIGHT A FAST MOVING SHORT WAVE COULD
PRODUCE SCATTERED TSTMS WITH IFR CIGS AT LCH, LFT, AND ARA. BPT
SHOULD STAY IFR CIGS WITH FOG DEVELOPING THIS EVENING. AEX WILL GO
FROM VFR TO IFR CIGS THIS EVENING. ALL THE TERMINALS SHOULD SEE
MVFR COME MORNING WITH THE POSSIBLILITY OF VFR LATE IN THE
AFTERNOON OR EARLY SATURDAY EVENING AS MOISTURE HEADS OUT TO THE
EAST.
JS
PREV DISCUSSION... /ISSUED 354 PM CDT FRI APR 24 2015/
DISCUSSION...
BUSY AFTERNOON TRACKING SEVERE SUPERCELL ACROSS SE TX INTO S
LA...PRODUCING DAMAGE ALONG MOST OF ITS PATH. ADDITIONAL SHRA/TSRA
TRIED TO DEVELOP BEHIND IT...BUT HAS SINCE DISSIPATED.
NOW...SVR WX THREAT IS NOT OVER YET. THE NEXT ROUND OF SHRA/TSRA
IS DEVELOPING ACROSS C AND NE TX NOW...AND IS EXPECTED TO MOVE SE
ACROSS OUR REGION LATER THIS EVENING ACROSS INLAND SE TX...AND THE
REMAINDER OF THE AREA AFTER MIDNIGHT INTO DAYBREAK. A SLIGHT RISK
OF SVR TSTM WILL CONTINUE WITH THESE CELLS...WITH HAIL...DAMAGING
WINDS...AND POSSIBLE TORNADOES.
GET A BRIEF REPRIEVE FROM THE SVR WEATHER LATER SAT INTO SUN. YET
ANOTHER STRONG UPPER LEVEL DISTURBANCE IS EXPECTED TO BRING ANOTHER
ROUND OF TSRA BY LATE MON/TUE...WITH A POSSIBILITY OF SVR WX...AS
OUTLINED IN THE DAY 4 SPC OUTLOOK.
BY LATE TUE INTO WED AND THE REMAINDER OF THE EXTENDED...COOLER
AND DRIER AIR BRING THE TEMPS BACK TO NEAR NORMAL WITH NO PRECIP
EXPECTED.
DML
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 71 88 68 90 / 60 40 10 10
LCH 72 83 70 86 / 60 50 10 10
LFT 73 85 70 88 / 50 50 10 10
BPT 72 84 69 85 / 60 50 10 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...11
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 AM EDT SAT APR 25 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM EDT FRI APR 24 2015
FLOW ALOFT BRIEFLY HAS BECOME WESTERLY WHICH IS ALLOWING WARM
ADVECTION OCCURRING NORTH OF WEAK SFC WARM FRONT OVER SOUTHERN
MINNESOTA TO AFFECT FAR WESTERN GREAT LAKES. LOW-LEVELS BLO H85 PER
12Z SOUNDINGS FM GRB/INL/MPX REMAIN QUITE DRY...BUT MOISTURE AND
WARM ADVECTION MAINLY AT H7 IS DRIVING AREA OF SCT LIGHT SHOWERS
OVER NORTHWEST WI. EVEN SOME SNOW WAS REPORTED IN NORTHEAST
MINNESOTA EARLIER TODAY AS TEMPS WERE IN THE 30S AS THE PRECIP BEGAN.
BASED ON WHERE RAP/NAM SHOW NOSE OF H7 MOISTURE TRANSPORT INTO THIS
EVENING...SOME OF THE SHRA OVER NORTHWEST WI MAY CLIP SW UPR
MICHIGAN THROUGH MIDNIGHT. GREATEST CHANCES FM IRONWOOD TO IRON
RIVER. WEAK FORCING ALOFT AND PERSISTENT DRY LOW-LEVELS WILL
PROHIBIT THE PRECIP FM MAKING IT VERY FAR TO THE NORTH AND EAST OF
THOSE AREAS. LATEST HRRR MODEL RUNS ARE PICKING UP ON THIS...SHOWING
ANY SIMULATED REFLECTIVITY AT 1KM OF NOTE FADING AS IT MOVES INTO
SCNTRL UPR MICHIGAN. AS TEMPS COOL ENOUGH IN BLYR AFTER SUNSET...MAY
SEE RAIN TRY TO TURN TO SNOW BRIEFLY BEFORE THE WANING FORCING
ALLOWS THIS PRECIP TO END. NOT EXPECTING ANYTHING MORE THAN A
COATING OF SNOW ACCUMULATION IF IT OCCURS AT ALL. TEMPS TONIGHT WILL
BE COOLEST IN THE EAST /UPR TEENS TO LOW 20S/ CLOSER TO SFC HIGH AND
WHERE SKIES STAY MOSTLY CLEAR. ELSEWHERE EXPECT READINGS IN UPR 20S
TO MID 30S...WARMEST WEST.
MID CLOUDS GRADUALLY FADE AWAY ON SATURDAY AS SFC HIGH PRESSURE
BUILDS IN FM HUDSON BAY. NORTHERLY GRADIENT WINDS TIED INTO THE HIGH
WILL KEEP AREAS NEAR LK SUPERIOR SHORE STUCK IN THE 30S DESPITE THE
INCREASING SUNSHINE. WARMEST TEMPS INTO THE LOW 50S WILL BE ALONG WI
BORDER AND ALSO NEAR LK MICHIGAN WITH NORTH WINDS COMING OFF THE
LAND OF EAST HALF OF UPR MICHIGAN.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 342 PM EDT FRI APR 24 2015
SAT NIGHT AND SUN...SFC RIDGING AND DRY WEATHER IS EXPECTED TO
DOMINATE THE WRN GREAT LAKES AS A MID LEVEL RIDGE BUILDS TOWARD MN
AND NW ONTARIO AND TROUGH LINGERS FROM NRN NEW ENGLAND THROUGH THE
ERN GREAT LAKES. WITH LIGHT NE TO N LOW LEVEL FLOW...TEMPS WILL
REMAIN BELOW NORMAL...ESPECIALLY NEAR LAKE SUPERIOR WHERE HIGHS WILL
REACH ONLY INTO THE LOWER 40S. READINGS TO AROUND 50 WILL PREVAIL
OVER THE SOUTH HALF.
THE SFC HIGH WILL CONTINUE TO RIDGE S INTO UPPER MI ON MON...SO MON
WILL BE SIMILAR TO SUN. HOWEVER...WITH THE PRES GRADIENT WEAKENING
AND A SLIGHT MODERATION OF AIR MASS...MAX TEMPS MON SHOULD BE
SEVERAL DEGREES HIGHER THAN SUN...ESPECIALLY IN THE INTERIOR.
MEDIUM RANGE MODELS INDICATE A SHORTWAVE MOVING ACROSS THE NRN
PLAINS MON NIGHT. AS MID/UPPER RIDGE BEGINS BUILDING OVER THE
ROCKIES...THIS WAVE MAY END UP DIVING SE OR S TOWARD A SRN TROF OVER
TX/LWR MISSISSIPPI VALLEY REGION PER 12Z RUNS OF GFS AND GEM AND
23/12Z ECMWF...RESULTING IN CONTINUED DRY WEATHER HERE. THE 24/00Z
AND 24/12Z RUNS OF THE ECMWF HAVE TRENDED STRONGER WITH THE
SHORTWAVE SHOWING A MORE AGGRESSIVE EASTWARD PROGRESSION BEFORE
DIVING THE SHORTWAVE SE. THIS SOLN MAY RESULT IN SOME LIGHT SHRA
SPREADING INTO UPPER MI TUE INTO WED MORNING. GIVEN THAT LATEST
ECMWF STILL SHOWS THE MORE AGGRESSIVE EASTWARD PROGRESSION WITH
SHORTWAVE WILL MAINTAIN SLIGHT CHC POPS FOR SHRA OVER THE CWA TUE
INTO WED. CAA IN N-NE FLOW AHEAD OF BUILDING SFC HIGH FM CANADA AS
DEPICTED BY 12Z ECMWF WL KEEP TEMPS COOLER WED INTO WED NIGHT
PROBABLY SIMILAR TO EXPECTED BELOW NORMAL READINGS THIS WEEKEND.
THU-FRI...SFC HIGH PRES BUILDS BACK OVER THE REGION AND SINCE BOTH
12Z GFS AND ECMWF HAVE TRENDED FARTHER NORTH WITH SERIES OF
SHORTWAVES MOVING ACROSS SCNTRL CANADA EXPECT GENERALLY DRY
CONDITIONS TO PREVAIL. GENERAL TREND OF 00Z MEDIUM RANGE GUIDANCE IS
FOR UPSTREAM MID-UPR LVL RIDGING OVER THE WRN CONUS TO BE A BIT MORE
PRONOUNCED WHICH RESULTS IN A SHARPER NW FLOW DEVELOPING INTO THE
UPPER LAKES. THIS WOULD TEMPER THE WARMUP INTO THE WRN GREAT LAKES
FOR LATE WEEK AND MAY RESULT IN TEMPS CLOSER TO NORMAL INSTEAD OF
ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 136 AM EDT SAT APR 25 2015
ALTHOUGH THERE WL BE QUITE A BIT OF CLDS EARLY THIS MRNG WELL TO THE
N OF A WARM FNT IN THE UPR MIDWSET...A DRY LLVL NE FLOW OUT OF HI
PRES OVER NW ONTARIO WL RESULT IN VFR CONDITIONS AT ALL 3 TAF SITES
THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 241 PM EDT FRI APR 24 2015
HIGH PRESSURE WILL BE THE DOMINANT WEATHER FACTOR OVER THE UPPER
GREAT LAKES THIS WEEKEND AND THROUGH MUCH OF NEXT WEEK. OVERALL THE
WINDS WILL STAY AT OR BLO 20 KTS. THE ONE MAIN EXCEPTION WILL BE
TONIGHT AND SATURDAY OVER WESTERN LK SUPERIOR WHERE EAST TO
NORTHEAST WINDS OF 20-25 KTS WITH GUSTS TO AROUND 30 KTS ARE
EXPECTED AS STRONGER HIGH PRESSURE AREA INITIALLY BUILDS OVER THE
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1132 PM CDT FRI APR 24 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 250 PM CDT FRI APR 24 2015
THE PRIMARY FORECAST CONCERNS IN THE SHORT TERM ARE POTENTIAL FOR
SEVERE STORMS...MAINLY BEFORE 08Z...AND THEN RAIN CHANCES LINGERING
ON SATURDAY. SOME AREAS OF HEAVY RAIN ARE POSSIBLE TONIGHT.
SURFACE ANALYSIS AT MID AFTERNOON SHOWED TWO LOW PRESSURE CENTERS.
ONE WAS OVER WESTERN KANSAS AND THE OTHER WAS OVER CENTRAL SOUTH
DAKOTA. THE FIRST LOW WILL STRENGTHEN OVERNIGHT AND TRACK INTO
NORTHWEST MISSOURI BY DAYBREAK SATURDAY. MODEST LOW LEVEL MOISTURE
HAD MOVED NORTHWARD INTO THE FORECAST AREA WITH DEWPOINTS IN THE
LOWER TO MID 50S AT MANY LOCATIONS. LATEST SPC MESOSCALE ANALYSIS
SHOWED THE MIXED LAYER CAPE AXIS EXTENDING FROM CENTRAL KANSAS TO
SOUTHWEST NEBRASKA THEN INTO NORTH CENTRAL NEBRASKA. EFFECTIVE
SHEAR VALUES AS OF 19Z WERE MOSTLY LESS THAN 30 KNOTS LOCALLY.
MID LEVEL LAPSE RATES WERE MOSTLY 7.5 TO 8.5 DEGREES C PER KM.
EXPECT THAT STORMS WILL INCREASE IN COVERAGE TO OUR WEST AND SOUTH
LATER THIS AFTERNOON AND EVENING...THEN CONTINUE FOR THE OVERNIGHT.
RECENT HRRR AND RAP MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THAT.
SEVERE THREAT APPEARS TO BE MAINLY HAIL AND THAT MAINLY IN OUR
FAR SOUTHWEST COUNTIES AS STORMS LIFT/MOVE NORTHEAST FROM KANSAS.
THERE IS ALSO SOME THREAT OF HAIL WITH STORMS THAT MAY AFFECT
PARTS OF NORTHEAST NEBRASKA MAINLY BEFORE MIDNIGHT. HIGHEST
POTENTIAL FOR PCPN AMOUNTS OF AN INCH OR MORE IS ACROSS SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA...BUT ALL AREAS COULD SEE LOCALLY
HEAVY RAIN.
ON SATURDAY...PCPN SHOULD DECREASE IN COVERAGE AND INTENSITY DURING
THE MORNING. SOME LIGHT SHOWERS COULD LINGER INTO THE AFTERNOON...
MAINLY IN SOUTHWEST IOWA. OTHERWISE...A WEAK RIDGE OF HIGH PRESSURE
WILL BUILD INTO THE FORECAST AREA WITH NORTHERLY WINDS. CLOUDS ARE
EXPECTED TO LIMIT HEATING...SO KEPT MOST HIGHS SATURDAY IN THE MID
50S TO LOWER 60S.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 250 PM CDT FRI APR 24 2015
THIS PERIOD SHOULD BE MAINLY DRY WITH MODERATING TEMPERATURES. A
CLOSED LOW AT 500 MB IS EXPECTED TO BE OVER THE TEXAS PANHANDLE AT
THE START OF THIS PERIOD. THIS WILL TRACK OFF TO THE NORTHEAST AND
OPEN UP THROUGH MID WEEK AS A RIDGE BUILDS IN FROM THE NORTHWEST.
THE EARLY PART OF THE WEEK MAY NOT BE COMPLETELY DRY...BUT AT THIS
TIME PCPN CHANCES SEEMED TO BE 14 PERCENT OR LESS FOR ANY GIVEN
PERIOD. HIGHS WILL START OUT IN THE 60S MONDAY/TUESDAY...THEN WARM
TO THE 70S BY THURSDAY AND POSSIBLY NEAR 80 BY FRIDAY.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1129 PM CDT FRI APR 24 2015
VARIABLE CONDITIONS WILL CONTINUE ACROSS THE TAF SITES AS AN UPPER
LOW PRESSURE SYSTEM PASSES OVERHEAD. SCATTERED SHOWERS AND A FEW
ISOLATED THUNDERSTORMS ARE POSSIBLE INTO THE EARLY MORNING HOURS.
OCCASSIONAL IFR CONDITIONS ARE EXPECTED AS WELL THROUGH THE
OVERNIGHT HOURS AND COULD LINGER INTO SATURDAY MORNING AS LOW
LEVEL MOISTURE REMAINS OVER THE AREA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
415 AM CDT SAT APR 25 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT APR 25 2015
THE MAIN FOCUS FOR THE SHORT TERM THIS MORNING IS LOW CLOUD COVER
AND FOG...LEADING TO AVIATION ISSUES. THE FOCUS THEN TURNS TO
PRECIPITATION ACROSS THE WEST THIS AFTERNOON/EVENING.
EASTERLY UPSLOPE SURFACE FLOW IS BRINGING IN LOW LEVEL MOISTURE
AND RESULTING IN VERY LOW STRATUS AND FOG DEVELOPMENT. CURRENTLY
ABOUT 2/3 OF NORTH DAKOTA IS COVERED. THE STRATUS DECK SHOULD MAKE
IT ALL THE WAY TO MONTANA THIS MORNING. THE LATEST HRRR AND RAP
INDICATE CLOUD COVER AND FOG WILL CONTINUE THROUGH THE EARLY
AFTERNOON HOURS. AS FORCING BECOMES FOCUSED ACROSS WESTERN NORTH
DAKOTA THIS AFTERNOON AND MID-LEVEL FLOW INCREASES AHEAD OF THE
AN UPPER-LEVEL SHORTWAVE TROUGH...CLOUD CEILINGS SHOULD LIFT AND
BEGIN TO SCATTER OUT.
THE LATEST TREND IN THE MODELS IS TO DELAY PRECIPITATION FROM
ENTERING NORTH DAKOTA UNTIL LATE THIS AFTERNOON. CONTINUED THE
TRENDS FROM EARLIER FORECAST UPDATES AND PUSHED PRECIP CHANCES
EVEN FURTHER WESTWARD AND DELAYED ONSET. HOWEVER...UNLIKE
PREVIOUSLY THOUGHT IT DOES APPEAR THAT THERE COULD BE A FEW
ISOLATED THUNDERSTORMS. THE 00 AND 06 UTC MODELS BRING AN AXIS OF
INSTABILITY ACROSS WESTERN NORTH DAKOTA AS FAR NORTH AS THE
CANADIAN BOARDER. AS SUCH INCLUDED THE MENTION OF THUNDERSTORMS
IN THE FORECAST FOR WESTERN NORTH DAKOTA LATE THIS AFTERNOON.
TONIGHT A BAND OF RAIN WILL SLOWLY MOVE ACROSS WESTERN NORTH
DAKOTA...INTO CENTRAL NORTH DAKOTA BY TOMORROW MORNING. WITH VERY
LITTLE PROGRESSION OF THE MAIN FEATURES (SURFACE LOW...LONG WAVE
TROUGH OUT WEST...ETC.) EXPECTED OVER THE NEXT DAY...SEVERAL HOURS
OF MUCH NEED LIGHT RAIN APPEARS LIKELY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT APR 25 2015
AN UNSETTLED WEATHER PATTERN SLOWLY SPREADING FROM WEST TO EAST
SATURDAY THROUGH MONDAY HIGHLIGHTS THE EARLY PORTION OF THE
EXTENDED PERIOD. A SPLIT FLOW REGIME WITH TWO SIGNIFICANT
SHORTWAVE TROUGHS WILL AFFECT THE NORTHERN PLAINS.
FOR SUNDAY-SUNDAY NIGHT...LOW LEVEL MOISTURE WILL CONTINUE TO
SPREAD ACROSS THE REGION. EMBEDDED S/WV IMPULSE ORIGINATING FROM
A DEEP UPPER LOW OVER THE SOUTHERN ROCKIES WILL ROTATE NORTH
ACROSS THE CENTRAL HIGH PLAINS...THEN GETS CAUGHT UP IN THE
NORTHERN STREAM AND SLOWLY MOVES ACROSS MY WEST LIFTING NORTHEAST
BY MONDAY 12Z. BEST VERTICAL MOTION WILL OCCUR ALONG A QUASI-
STATIONARY FRONT INITIALLY ACROSS WESTERN NORTH DAKOTA...AND WILL
MAINTAIN ELEVATED POPS THERE SUNDAY DAYTIME. FRONT STARTS TO
ORIENTATE SOUTHWEST TO NORTHEAST...ALLOWING SHOWERS TO CONTINUE
WEST AND SPREAD INTO THE NORTH CENTRAL SUNDAY NIGHT. SHOULD BE
MAINLY DRY FOR THIS PERIOD ACROSS MY SOUTHEAST.
FOR EARLY MONDAY THROUGH MONDAY NIGHT...NORTHERN STREAM TROUGH
APPROACHES AND PUSHES EAST ACROSS THE STATE...RE-ENERGIZING THE
SURFACE COLD FRONT AND PRODUCING ANOTHER ROUND OF SHOWERS
SPREADING FROM WEST TO EAST. IT WILL BE DURING THIS TIME PERIOD
THAT THE HIGHEST PROBABILITY FOR RAIN WILL OCCUR IN CENTRAL NORTH
DAKOTA.
TOTAL RAINFALL AMOUNTS STILL LOOK LIKE A HALF INCH TO ONE INCH
WEST WITH AROUND A QUARTER OF AN INCH CENTRAL THROUGH MONDAY
NIGHT.
TUESDAY THROUGH FRIDAY...MAINLY DRY AND WARM CONDITIONS AS A
MID/UPPER LEVEL RIDGE SLOWLY MOVES EAST ACROSS THE ROCKIES AND
INTO THE GREAT PLAINS. AFTERNOON HIGHS WEDNESDAY AND THURSDAY
WILL MOSTLY BE IN THE 70S...WITH POSSIBLY SOME LOWER 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 410 AM CDT SAT APR 25 2015
IFR CONDITIONS LIKELY AT KMOT/KBIS/KJMS/KDIK...WITH MVFR POSSIBLE
AT KISN. LOW LEVEL EASTERLY WINDS ACROSS WESTERN AND CENTRAL
NORTH DAKOTA WILL REMAIN THROUGH SATURDAY. AS A RESULT LOW LEVEL
CLOUDS WILL CONTINUE TO SPREAD INTO WESTERN AND CENTRAL NORTH
DAKOTA TONIGHT AND CONTINUE SATURDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...NH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
216 AM CDT SAT APR 25 2015
.UPDATE...
A CLUSTER OF SHOWERS AND THUNDERSTORMS HAVE DEVELOPED FROM SABINAL
TO DEL RIO GENERALLY IN THE SAME AREAS THAT SOME OF THE HI-RES
MODELS INDICATED. THESE SHOWERS AND THUNDERSTORMS WILL CONTINUE
INTO THE EARLY MORNING HOURS ACROSS MUCH OF THE HILL COUNTRY TO
ALONG THE ESCARPMENT. SOME STORMS COULD BE SEVERE DUE HIGH CAPES
AND COULD ALSO SEE SOME LOCALLY HEAVY DOWNPOURS ACROSS THE AREAS
FROM DEL RIO TO SAN ANTONIO AND INTO THE ADJACENT HILL COUNTRY.
BANDS OF SHOWERS AND THUNDERSTORMS HAVE FORMED OVER THE COASTAL
PLAINS AS WELL. EXPECT THESE TO REMAIN THERE WITH LITTLE IMPACT
FOR OUR SOUTHEASTERN COUNTIES. AS A RESULT...HAVE CANCELLED THE
FLASH FLOOD WATCH AS WIDESPREAD FLOODING IS NO LONGER EXPECTED.
REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 1244 AM CDT SAT APR 25 2015/
AVIATION...
THIS COULD BE A TRICKY FORECAST IN THE SHORT TERM. MODELS ARE NOT
HANDLING THE CURRENT SITUATION VERY WELL. LIFR CIGS HAVE FORMED AT
DRT AND CAN/T SEE MUCH REASON FOR THEM TO CHANGE OVERNIGHT. THEY
RETURN TO VFR AROUND SUNRISE WHEN WINDS TURN TO THE NORTH. THE SAN
ANTONIO AIRPORTS SHOULD BE IFR OVERNIGHT WHILE AUS WILL BE MVFR.
ALL SITES WILL BE VFR BY ABOUT 14Z. HAVE BROUGHT MVFR CIGS BACK TO
THE 30 HOUR TAFS AT 09Z TOMORROW.
PREV DISCUSSION... /ISSUED 1222 AM CDT SAT APR 25 2015/
UPDATE...
HAVE CANCELLED SEVERE THUNDERSTORM WATCH 104. STORMS HAVE WEAKENED
DUE TO INCREASING CAPPING INVERSION AND STABILITY. ALSO...HAVE
TRIMMED ATASCOSA...BEXAR...FRIO AND MEDINA FROM THE FLASH FLOOD
WATCH. DEVELOPMENT CONTINUES TO THE EAST AND WILL MAINTAIN IT
THERE. HOWEVER...MAY CANCEL THE REMAINDER OF THE FLASH FLOOD WATCH
BEFORE THE EARLY MORNING FORECAST PACKAGE IF CURRENT RADAR TRENDS
PERSIST. SOME OF THE HI-RES MODELS SHOW SHOWERS AND THUNDERSTORMS
DEVELOPING OVER THE HILL COUNTRY TO THE ESCARPMENT OVERNIGHT. FOR
NOW...WILL DISREGARD AS MOISTURE DEPTH IS DECREASING. REMAINDER OF
SOUTH CENTRAL TEXAS FORECAST IS ON TRACK.
PREV DISCUSSION... /ISSUED 1004 PM CDT FRI APR 24 2015/
UPDATE...HAVE UPDATED SEVERE THUNDERSTORM WATCH AREA TO REMOVE
COUNTIES WEST OF CURRENT ACTIVITY AND HAVE ADDED SOME
KARNES...DEWITT...LAVACA...AND GONZALES COUNTIES DOWNSTREAM.
RAIN/THUNDERSTORM CHANCES WERE ENHANCED WHERE CURRENT AND
PROJECTED ACTIVITY IS EXPECTED OVER THE NEXT 3-6 HOURS.
UNCERTAINTY REMAINS CONCERNING THE HEAVY RAINFALL POTENTIAL AND
AND WILL MAINTAIN THE FLASH FLOOD WATCH FOR NOW BUT WILL LIKELY BE
REVISITED IN NEXT COUPLE HOURS DEPENDING ON CONVECTIVE EVOLUTION.
MORE DETAILS CAN BE FOUND BELOW ON FOR THE NEXT 6-12 HOUR TIME
FRAME.
DISCUSSION...DECENT SHORTWAVE TROUGHING ACROSS THE SOUTH CENTRAL
PLAINS ALONG WITH IMPULSES EMBEDDED IN THE BRISK H5-H3 SW FLOW
OVER THE REGION HAS LEAD TO SOME STRONG TO SEVERE STORM
DEVELOPMENT ACROSS THE RIO GRANDE PLAINS AND SOME COUNTIES
EASTWARD. MUCAPE VALUES REMAIN NEAR 3000 J/KG BUT IT APPEAR PER
MESO ANALYSIS THAT SOME LOW-LVL STABILIZATION IS BEGINNING TO
OCCUR. DESPITE THIS...AMPLE DIVERGENCE OVER THE REGION /70-90 KT
H5-H3 WIND FLOW/ LEADING TO NEAR 70 KT OF EFFECTIVE SHEAR IS ABLE
TO SUPPORT ROTATING UPDRAFTS AND ENHANCE A HAIL AND STRAIGHT-LINE
DAMAGING WIND RISK. THE TORNADO RISK WHILE LIMITED BEFORE WILL
EVEN FURTHER REDUCE AS STORMS ENTER NON-FAVORABLE SRH FIELDS.
STORMS THAT WERE BACK WEST IN ZAVALA AND DIMMIT COUNTIES AROUND
8PM HAD ENHANCED EFFECTIVE SRH NEAR 200 M2/S2. IT APPEARS A MINI
SUPERCELL DEVELOPED ALONG THE LEADING EDGE OF A FLANKING BOUNDARY
ATTENDANT TO ANOTHER SUPERCELL THAT WAS ABLE TO INGEST ENHANCED
LOW-LVL HELICITY FOR THE FUNNEL AND LIKELY BRIEF TORNADO THAT
OCCURRED. AGAIN...THIS RISK IS DIMINISHED QUICKLY GIVEN
UNFAVORABLE LOW-LVL SHEAR IN PLACE. SOME QUARTER SIZE HAIL...BRIEF
SEVERE WIND GUSTS TO 60 MPH AND HEAVY RAIN WILL REMAIN A
POSSIBILITY THROUGH THE LATE EVENING INTO EARLY SATURDAY MORNING.
THE HRRR CONTINUES TO TRY AND MERGE THESE CELLS ACROSS ATASCOSA
COUNTY INTO A LINE ACROSS THE SOUTHEAST PRAIRIE COUNTIES...WHILE
THIS IS PLAUSIBLE...IT REDUCES THE OVERALL RISK FOR WIDESPREAD
HEAVY RAIN. SOME SHORT TERM MODELS SUGGEST NEW DEVELOPMENT UPWIND
OF CURRENT ACTIVITY BUT CONFIDENCE IS LOW IS THIS SCENARIO. IF
CURRENT TRENDS HOLD...THE FLASH FLOOD WATCH MAY BE CUT BACK OR
CANCELLED IN ANOTHER UPDATE THIS EVENING. BULK OF THE ACTIVITY
SHOULD MOVE EAST OF THE REGION BY 3AM...IF NOT SOONER...AND THE
AREA BE CLEAR OF ALL HAZARDS BY THAT TIME.
ALLEN
PREV DISCUSSION... /ISSUED 656 PM CDT FRI APR 24 2015/
AVIATION...
/00Z TAFS/
ONGOING CONVECTION JUST TO THE SOUTHEAST OF KDRT WILL CONTINUE TO
MOVE TO THE NORTHEAST. NEW STORMS ARE EXPECTED TO DEVELOP WITHIN
THE NEXT HOUR OR TWO AND APPROACH KSAT AND KSSF AROUND 01Z AND 02Z
OVER KAUS. HIRES SOLUTIONS CLEAR THE KAUS AREA AFTER 04Z BUT KEEP
SHOWERS/STORMS ACROSS SAN ANTONIO THROUGH 05Z SATURDAY. SOME OF
THESE STORMS COULD BE STRONG TO SEVERE AS THEY MOVE ACROSS THE
I-35 CORRIDOR. AT THIS TIME...WILL NOT INCLUDE THUNDERSTORM WIND
GUSTS AS STRONGER STORMS ARE FORECAST TO STAY TO THE SOUTHEAST AND
SOUTH OF THE TERMINALS. MVFR CONDITIONS ARE EXPECTED DURING THE
STORMS PERIOD...BUT CAN NOT RULE OUT IFR CIGS FOR A SHORT PERIOD
OF TIME. AFTER THE STORMS PUSH AWAY OVERNIGHT...WINDS WILL BECOME
LIGHT AND VARIABLE AND REMAIN THROUGH LATE SATURDAY MORNING. VFR
CONDITIONS ARE EXPECTED ACROSS THE I-35 SITES AFTER 13Z WHILE KDRT
REMAINS VFR THROUGH THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 256 PM CDT FRI APR 24 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
LOCALLY HEAVY RAINFALL LEADING TO FLASH FLOODING POSSIBLE
TONIGHT ACROSS SOUTHERN AND EASTERN AREAS...
STARTING TO SEE SOME RECOVERY AFTER THE EARLY MORNING MCS. SOME
POCKETS OF CLEARING ARE BEGINNING TO TAKE PLACE ACROSS THE
SOUTHWEST CWA AND FAR WESTERN VAL VERDE COUNTY...AND ALSO SEEING
CONVECTION BEGINNING TO DEVELOP ALONG THE HIGHER TERRAIN IN
MEXICO. ANALYSES INDICATES LOW LEVEL THETA-E RIDGE AXIS ALONG AND
JUST WEST OF THE RIO GRANDE...STILL SOME CIN TO OVERCOME JUST EAST
OF THE RIO GRANDE. WITH ADDITIONAL CLEARING DO EXPECT THE POTENTIAL
FOR SOME STORMS TO CROSS INTO MAVERICK...KINNEY AND/OR VAL VERDE
COUNTIES THROUGH 6 PM.
MODELS ARE IN GENERAL AGREEMENT WITH BROAD MID AND UPPER LEVEL
FORCING INCREASING WEST TO EAST THIS EVENING WITH APPROACH OF
SHORTWAVE...ALONG WITH BROAD ENTRANCE REGION TO UPPER LEVEL JET
STREAK LOCATED OVER THE CWA. SEVERAL HI RES MODELS INDICATE
SCATTERED TO NUMEROUS SHOWERS AND STORMS DEVELOPING EARLY THIS
EVENING SOUTHWEST OF SAN ANTONIO AND SPREADING NORTHEAST THROUGH
THE SOUTHERN AND EASTERN AREAS OF THE CWA THROUGH THE EVENING AND
OVERNIGHT HOURS. IN ADDITION...ARW/NMM/HRRR INDICATING STORMS
DEVELOPING OVER THE SJT CWA CLIPPING FAR NORTHERN AREAS UP NEAR
BURNET.
SUFFICIENT DEEP LAYER SHEAR AND STEEP ELEVATED LAPSE RATES/CAPE
WARRANT THE RISK FOR SOME STRONG TO SEVERE STORMS THIS EVENING...
PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS. BUT THE BIGGER
THREAT MAY BE LOCALLY HEAVY RAINFALL ESPECIALLY ALONG AND SOUTH OF
I-10/US 90. VERY HIGH PWAT AIRMASS STILL POOLED IN THIS REGION...
AND MODEL CONSENSUS OF 1 TO 2 INCHES OF QPF WITH ISOLATED POCKETS
OF 3 TO 4 OCCURRING BETWEEN THE CRP/EWX CWA BOUNDARY AND I-10. A
FLASH FLOOD WATCH HAS BEEN ISSUED FOR A PORTION OF THIS AREA...
COINCIDING WHERE HEAVY RAINFALL HAS ALREADY OCCURRED THE PAST
SEVERAL DAY. THE WATCH GOES AS FAR NORTH AS BASTROP AND LEE
COUNTIES (NOT INCLUDING TRAVIS OR WILLIAMSON)...DESPITE LESSER
AMOUNTS FORECAST IN THIS AREA. THIS IS OUT OF AN ABUNDANCE OF
CAUTION AS SOILS ARE SATURATED OVER MUCH OF THESE AREA...WITH
ONGOING FLOODING PROBLEMS CONTINUING IN BASTROP COUNTY.
PRECIP SHOULD EXIT TO THE EAST OF THE AREA EARLY SATURDAY MORNING.
A WEAK SURFACE BOUNDARY MOVES INTO THE AREA SATURDAY...WITH
SLIGHTLY DRIER AIR ALONG AND WEST OF I-35. A POOL OF MOISTURE
WILL STILL REMAIN ACROSS THE FAR SOUTHEAST ZONES...WHERE ISOLATED
SHOWERS OR THUNDERSTORMS WILL BE A POSSIBILITY SATURDAY AFTERNOON.
RUNYEN
LONG TERM (SUNDAY THROUGH FRIDAY)...THE BOUNDARY MOVES BACK WEST
OF THE I-35 CORRIDOR SUNDAY AND MONDAY...AS AN UPPER LEVEL LOW
DEEPENS ACROSS NEW MEXICO AND THE PANHANDLE. LOW CHANCES FOR
SHOWERS AND STORMS BOTH SUNDAY AND MONDAY ACROSS THE CENTRAL AND
EASTERN CWA AS WEAK FORCING INTERACTS WITH MOISTURE POOLED OVER
THE AREA. EVENTUALLY A COLD FRONT CLEARS THROUGH THE CWA ON
TUESDAY...AND DEEPER NORTHWEST FLOW DEVELOPS OVER THE AREA
WEDNESDAY THROUGH FRIDAY AS THE UPPER LEVEL TROUGH AXIS MOVES
EAST. LOOK FOR MORE SEASONAL TEMPS AND DRY CONDITIONS WEDNESDAY
THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 66 87 66 84 59 / 10 30 30 40 20
AUSTIN BERGSTROM INTL AIRPORT 67 86 65 83 59 / 10 30 30 40 20
NEW BRAUNFELS MUNI AIRPORT 67 87 67 84 60 / 10 30 30 40 10
BURNET MUNI AIRPORT 63 86 62 82 56 / 10 30 40 20 20
DEL RIO INTL AIRPORT 65 90 62 87 59 / 10 10 20 10 -
GEORGETOWN MUNI AIRPORT 66 86 64 83 58 / 10 30 30 30 20
HONDO MUNI AIRPORT 66 88 64 85 59 / 10 20 30 20 10
SAN MARCOS MUNI AIRPORT 67 86 66 83 60 / 10 30 30 40 20
LA GRANGE - FAYETTE REGIONAL 69 86 69 82 61 / 10 20 30 50 20
SAN ANTONIO INTL AIRPORT 67 88 67 85 60 / 10 20 30 20 10
STINSON MUNI AIRPORT 68 88 68 84 61 / 10 20 30 30 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...01
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1244 AM CDT SAT APR 25 2015
.AVIATION...
THIS COULD BE A TRICKY FORECAST IN THE SHORT TERM. MODELS ARE NOT
HANDLING THE CURRENT SITUATION VERY WELL. LIFR CIGS HAVE FORMED AT
DRT AND CAN/T SEE MUCH REASON FOR THEM TO CHANGE OVERNIGHT. THEY
RETURN TO VFR AROUND SUNRISE WHEN WINDS TURN TO THE NORTH. THE SAN
ANTONIO AIRPORTS SHOULD BE IFR OVERNIGHT WHILE AUS WILL BE MVFR.
ALL SITES WILL BE VFR BY ABOUT 14Z. HAVE BROUGHT MVFR CIGS BACK TO
THE 30 HOUR TAFS AT 09Z TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 1222 AM CDT SAT APR 25 2015/
UPDATE...
HAVE CANCELLED SEVERE THUNDERSTORM WATCH 104. STORMS HAVE WEAKENED
DUE TO INCREASING CAPPING INVERSION AND STABILITY. ALSO...HAVE
TRIMMED ATASCOSA...BEXAR...FRIO AND MEDINA FROM THE FLASH FLOOD
WATCH. DEVELOPMENT CONTINUES TO THE EAST AND WILL MAINTAIN IT
THERE. HOWEVER...MAY CANCEL THE REMAINDER OF THE FLASH FLOOD WATCH
BEFORE THE EARLY MORNING FORECAST PACKAGE IF CURRENT RADAR TRENDS
PERSIST. SOME OF THE HI-RES MODELS SHOW SHOWERS AND THUNDERSTORMS
DEVELOPING OVER THE HILL COUNTRY TO THE ESCARPMENT OVERNIGHT. FOR
NOW...WILL DISREGARD AS MOISTURE DEPTH IS DECREASING. REMAINDER OF
SOUTH CENTRAL TEXAS FORECAST IS ON TRACK.
PREV DISCUSSION... /ISSUED 1004 PM CDT FRI APR 24 2015/
UPDATE...HAVE UPDATED SEVERE THUNDERSTORM WATCH AREA TO REMOVE
COUNTIES WEST OF CURRENT ACTIVITY AND HAVE ADDED SOME
KARNES...DEWITT...LAVACA...AND GONZALES COUNTIES DOWNSTREAM.
RAIN/THUNDERSTORM CHANCES WERE ENHANCED WHERE CURRENT AND
PROJECTED ACTIVITY IS EXPECTED OVER THE NEXT 3-6 HOURS.
UNCERTAINTY REMAINS CONCERNING THE HEAVY RAINFALL POTENTIAL AND
AND WILL MAINTAIN THE FLASH FLOOD WATCH FOR NOW BUT WILL LIKELY BE
REVISITED IN NEXT COUPLE HOURS DEPENDING ON CONVECTIVE EVOLUTION.
MORE DETAILS CAN BE FOUND BELOW ON FOR THE NEXT 6-12 HOUR TIME
FRAME.
DISCUSSION...DECENT SHORTWAVE TROUGHING ACROSS THE SOUTH CENTRAL
PLAINS ALONG WITH IMPULSES EMBEDDED IN THE BRISK H5-H3 SW FLOW
OVER THE REGION HAS LEAD TO SOME STRONG TO SEVERE STORM
DEVELOPMENT ACROSS THE RIO GRANDE PLAINS AND SOME COUNTIES
EASTWARD. MUCAPE VALUES REMAIN NEAR 3000 J/KG BUT IT APPEAR PER
MESO ANALYSIS THAT SOME LOW-LVL STABILIZATION IS BEGINNING TO
OCCUR. DESPITE THIS...AMPLE DIVERGENCE OVER THE REGION /70-90 KT
H5-H3 WIND FLOW/ LEADING TO NEAR 70 KT OF EFFECTIVE SHEAR IS ABLE
TO SUPPORT ROTATING UPDRAFTS AND ENHANCE A HAIL AND STRAIGHT-LINE
DAMAGING WIND RISK. THE TORNADO RISK WHILE LIMITED BEFORE WILL
EVEN FURTHER REDUCE AS STORMS ENTER NON-FAVORABLE SRH FIELDS.
STORMS THAT WERE BACK WEST IN ZAVALA AND DIMMIT COUNTIES AROUND
8PM HAD ENHANCED EFFECTIVE SRH NEAR 200 M2/S2. IT APPEARS A MINI
SUPERCELL DEVELOPED ALONG THE LEADING EDGE OF A FLANKING BOUNDARY
ATTENDANT TO ANOTHER SUPERCELL THAT WAS ABLE TO INGEST ENHANCED
LOW-LVL HELICITY FOR THE FUNNEL AND LIKELY BRIEF TORNADO THAT
OCCURRED. AGAIN...THIS RISK IS DIMINISHED QUICKLY GIVEN
UNFAVORABLE LOW-LVL SHEAR IN PLACE. SOME QUARTER SIZE HAIL...BRIEF
SEVERE WIND GUSTS TO 60 MPH AND HEAVY RAIN WILL REMAIN A
POSSIBILITY THROUGH THE LATE EVENING INTO EARLY SATURDAY MORNING.
THE HRRR CONTINUES TO TRY AND MERGE THESE CELLS ACROSS ATASCOSA
COUNTY INTO A LINE ACROSS THE SOUTHEAST PRAIRIE COUNTIES...WHILE
THIS IS PLAUSIBLE...IT REDUCES THE OVERALL RISK FOR WIDESPREAD
HEAVY RAIN. SOME SHORT TERM MODELS SUGGEST NEW DEVELOPMENT UPWIND
OF CURRENT ACTIVITY BUT CONFIDENCE IS LOW IS THIS SCENARIO. IF
CURRENT TRENDS HOLD...THE FLASH FLOOD WATCH MAY BE CUT BACK OR
CANCELLED IN ANOTHER UPDATE THIS EVENING. BULK OF THE ACTIVITY
SHOULD MOVE EAST OF THE REGION BY 3AM...IF NOT SOONER...AND THE
AREA BE CLEAR OF ALL HAZARDS BY THAT TIME.
ALLEN
PREV DISCUSSION... /ISSUED 656 PM CDT FRI APR 24 2015/
AVIATION...
/00Z TAFS/
ONGOING CONVECTION JUST TO THE SOUTHEAST OF KDRT WILL CONTINUE TO
MOVE TO THE NORTHEAST. NEW STORMS ARE EXPECTED TO DEVELOP WITHIN
THE NEXT HOUR OR TWO AND APPROACH KSAT AND KSSF AROUND 01Z AND 02Z
OVER KAUS. HIRES SOLUTIONS CLEAR THE KAUS AREA AFTER 04Z BUT KEEP
SHOWERS/STORMS ACROSS SAN ANTONIO THROUGH 05Z SATURDAY. SOME OF
THESE STORMS COULD BE STRONG TO SEVERE AS THEY MOVE ACROSS THE
I-35 CORRIDOR. AT THIS TIME...WILL NOT INCLUDE THUNDERSTORM WIND
GUSTS AS STRONGER STORMS ARE FORECAST TO STAY TO THE SOUTHEAST AND
SOUTH OF THE TERMINALS. MVFR CONDITIONS ARE EXPECTED DURING THE
STORMS PERIOD...BUT CAN NOT RULE OUT IFR CIGS FOR A SHORT PERIOD
OF TIME. AFTER THE STORMS PUSH AWAY OVERNIGHT...WINDS WILL BECOME
LIGHT AND VARIABLE AND REMAIN THROUGH LATE SATURDAY MORNING. VFR
CONDITIONS ARE EXPECTED ACROSS THE I-35 SITES AFTER 13Z WHILE KDRT
REMAINS VFR THROUGH THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 256 PM CDT FRI APR 24 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
LOCALLY HEAVY RAINFALL LEADING TO FLASH FLOODING POSSIBLE
TONIGHT ACROSS SOUTHERN AND EASTERN AREAS...
STARTING TO SEE SOME RECOVERY AFTER THE EARLY MORNING MCS. SOME
POCKETS OF CLEARING ARE BEGINNING TO TAKE PLACE ACROSS THE
SOUTHWEST CWA AND FAR WESTERN VAL VERDE COUNTY...AND ALSO SEEING
CONVECTION BEGINNING TO DEVELOP ALONG THE HIGHER TERRAIN IN
MEXICO. ANALYSES INDICATES LOW LEVEL THETA-E RIDGE AXIS ALONG AND
JUST WEST OF THE RIO GRANDE...STILL SOME CIN TO OVERCOME JUST EAST
OF THE RIO GRANDE. WITH ADDITIONAL CLEARING DO EXPECT THE POTENTIAL
FOR SOME STORMS TO CROSS INTO MAVERICK...KINNEY AND/OR VAL VERDE
COUNTIES THROUGH 6 PM.
MODELS ARE IN GENERAL AGREEMENT WITH BROAD MID AND UPPER LEVEL
FORCING INCREASING WEST TO EAST THIS EVENING WITH APPROACH OF
SHORTWAVE...ALONG WITH BROAD ENTRANCE REGION TO UPPER LEVEL JET
STREAK LOCATED OVER THE CWA. SEVERAL HI RES MODELS INDICATE
SCATTERED TO NUMEROUS SHOWERS AND STORMS DEVELOPING EARLY THIS
EVENING SOUTHWEST OF SAN ANTONIO AND SPREADING NORTHEAST THROUGH
THE SOUTHERN AND EASTERN AREAS OF THE CWA THROUGH THE EVENING AND
OVERNIGHT HOURS. IN ADDITION...ARW/NMM/HRRR INDICATING STORMS
DEVELOPING OVER THE SJT CWA CLIPPING FAR NORTHERN AREAS UP NEAR
BURNET.
SUFFICIENT DEEP LAYER SHEAR AND STEEP ELEVATED LAPSE RATES/CAPE
WARRANT THE RISK FOR SOME STRONG TO SEVERE STORMS THIS EVENING...
PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS. BUT THE BIGGER
THREAT MAY BE LOCALLY HEAVY RAINFALL ESPECIALLY ALONG AND SOUTH OF
I-10/US 90. VERY HIGH PWAT AIRMASS STILL POOLED IN THIS REGION...
AND MODEL CONSENSUS OF 1 TO 2 INCHES OF QPF WITH ISOLATED POCKETS
OF 3 TO 4 OCCURRING BETWEEN THE CRP/EWX CWA BOUNDARY AND I-10. A
FLASH FLOOD WATCH HAS BEEN ISSUED FOR A PORTION OF THIS AREA...
COINCIDING WHERE HEAVY RAINFALL HAS ALREADY OCCURRED THE PAST
SEVERAL DAY. THE WATCH GOES AS FAR NORTH AS BASTROP AND LEE
COUNTIES (NOT INCLUDING TRAVIS OR WILLIAMSON)...DESPITE LESSER
AMOUNTS FORECAST IN THIS AREA. THIS IS OUT OF AN ABUNDANCE OF
CAUTION AS SOILS ARE SATURATED OVER MUCH OF THESE AREA...WITH
ONGOING FLOODING PROBLEMS CONTINUING IN BASTROP COUNTY.
PRECIP SHOULD EXIT TO THE EAST OF THE AREA EARLY SATURDAY MORNING.
A WEAK SURFACE BOUNDARY MOVES INTO THE AREA SATURDAY...WITH
SLIGHTLY DRIER AIR ALONG AND WEST OF I-35. A POOL OF MOISTURE
WILL STILL REMAIN ACROSS THE FAR SOUTHEAST ZONES...WHERE ISOLATED
SHOWERS OR THUNDERSTORMS WILL BE A POSSIBILITY SATURDAY AFTERNOON.
RUNYEN
LONG TERM (SUNDAY THROUGH FRIDAY)...THE BOUNDARY MOVES BACK WEST
OF THE I-35 CORRIDOR SUNDAY AND MONDAY...AS AN UPPER LEVEL LOW
DEEPENS ACROSS NEW MEXICO AND THE PANHANDLE. LOW CHANCES FOR
SHOWERS AND STORMS BOTH SUNDAY AND MONDAY ACROSS THE CENTRAL AND
EASTERN CWA AS WEAK FORCING INTERACTS WITH MOISTURE POOLED OVER
THE AREA. EVENTUALLY A COLD FRONT CLEARS THROUGH THE CWA ON
TUESDAY...AND DEEPER NORTHWEST FLOW DEVELOPS OVER THE AREA
WEDNESDAY THROUGH FRIDAY AS THE UPPER LEVEL TROUGH AXIS MOVES
EAST. LOOK FOR MORE SEASONAL TEMPS AND DRY CONDITIONS WEDNESDAY
THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 89 66 86 66 83 / - 0 30 30 40
AUSTIN BERGSTROM INTL AIRPORT 88 63 85 65 83 / 10 - 30 30 40
NEW BRAUNFELS MUNI AIRPORT 88 65 86 67 83 / 10 - 30 30 30
BURNET MUNI AIRPORT 86 61 85 62 82 / 0 0 30 30 30
DEL RIO INTL AIRPORT 88 64 90 63 87 / 0 - - 20 -
GEORGETOWN MUNI AIRPORT 88 63 85 65 82 / 0 0 30 30 40
HONDO MUNI AIRPORT 88 65 88 64 85 / - - 20 30 20
SAN MARCOS MUNI AIRPORT 87 64 85 66 83 / 10 - 30 30 40
LA GRANGE - FAYETTE REGIONAL 87 67 85 69 81 / 20 - 30 20 40
SAN ANTONIO INTL AIRPORT 89 67 87 67 85 / 10 - 30 30 30
STINSON MUNI AIRPORT 88 66 87 67 84 / 10 - 30 30 30
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 5 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING COUNTIES: BASTROP...CALDWELL...DE WITT...FAYETTE...
GONZALES...GUADALUPE...KARNES...LAVACA...LEE...WILSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...01
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1222 AM CDT SAT APR 25 2015
.UPDATE...
HAVE CANCELLED SEVERE THUNDERSTORM WATCH 104. STORMS HAVE WEAKENED
DUE TO INCREASING CAPPING INVERSION AND STABILITY. ALSO...HAVE
TRIMMED ATASCOSA...BEXAR...FRIO AND MEDINA FROM THE FLASH FLOOD
WATCH. DEVELOPMENT CONTINUES TO THE EAST AND WILL MAINTAIN IT
THERE. HOWEVER...MAY CANCEL THE REMAINDER OF THE FLASH FLOOD WATCH
BEFORE THE EARLY MORNING FORECAST PACKAGE IF CURRENT RADAR TRENDS
PERSIST. SOME OF THE HI-RES MODELS SHOW SHOWERS AND THUNDERSTORMS
DEVELOPING OVER THE HILL COUNTRY TO THE ESCARPMENT OVERNIGHT. FOR
NOW...WILL DISREGARD AS MOISTURE DEPTH IS DECREASING. REMAINDER OF
SOUTH CENTRAL TEXAS FORECAST IS ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 1004 PM CDT FRI APR 24 2015/
UPDATE...HAVE UPDATED SEVERE THUNDERSTORM WATCH AREA TO REMOVE
COUNTIES WEST OF CURRENT ACTIVITY AND HAVE ADDED SOME
KARNES...DEWITT...LAVACA...AND GONZALES COUNTIES DOWNSTREAM.
RAIN/THUNDERSTORM CHANCES WERE ENHANCED WHERE CURRENT AND
PROJECTED ACTIVITY IS EXPECTED OVER THE NEXT 3-6 HOURS.
UNCERTAINTY REMAINS CONCERNING THE HEAVY RAINFALL POTENTIAL AND
AND WILL MAINTAIN THE FLASH FLOOD WATCH FOR NOW BUT WILL LIKELY BE
REVISITED IN NEXT COUPLE HOURS DEPENDING ON CONVECTIVE EVOLUTION.
MORE DETAILS CAN BE FOUND BELOW ON FOR THE NEXT 6-12 HOUR TIME
FRAME.
DISCUSSION...DECENT SHORTWAVE TROUGHING ACROSS THE SOUTH CENTRAL
PLAINS ALONG WITH IMPULSES EMBEDDED IN THE BRISK H5-H3 SW FLOW
OVER THE REGION HAS LEAD TO SOME STRONG TO SEVERE STORM
DEVELOPMENT ACROSS THE RIO GRANDE PLAINS AND SOME COUNTIES
EASTWARD. MUCAPE VALUES REMAIN NEAR 3000 J/KG BUT IT APPEAR PER
MESO ANALYSIS THAT SOME LOW-LVL STABILIZATION IS BEGINNING TO
OCCUR. DESPITE THIS...AMPLE DIVERGENCE OVER THE REGION /70-90 KT
H5-H3 WIND FLOW/ LEADING TO NEAR 70 KT OF EFFECTIVE SHEAR IS ABLE
TO SUPPORT ROTATING UPDRAFTS AND ENHANCE A HAIL AND STRAIGHT-LINE
DAMAGING WIND RISK. THE TORNADO RISK WHILE LIMITED BEFORE WILL
EVEN FURTHER REDUCE AS STORMS ENTER NON-FAVORABLE SRH FIELDS.
STORMS THAT WERE BACK WEST IN ZAVALA AND DIMMIT COUNTIES AROUND
8PM HAD ENHANCED EFFECTIVE SRH NEAR 200 M2/S2. IT APPEARS A MINI
SUPERCELL DEVELOPED ALONG THE LEADING EDGE OF A FLANKING BOUNDARY
ATTENDANT TO ANOTHER SUPERCELL THAT WAS ABLE TO INGEST ENHANCED
LOW-LVL HELICITY FOR THE FUNNEL AND LIKELY BRIEF TORNADO THAT
OCCURRED. AGAIN...THIS RISK IS DIMINISHED QUICKLY GIVEN
UNFAVORABLE LOW-LVL SHEAR IN PLACE. SOME QUARTER SIZE HAIL...BRIEF
SEVERE WIND GUSTS TO 60 MPH AND HEAVY RAIN WILL REMAIN A
POSSIBILITY THROUGH THE LATE EVENING INTO EARLY SATURDAY MORNING.
THE HRRR CONTINUES TO TRY AND MERGE THESE CELLS ACROSS ATASCOSA
COUNTY INTO A LINE ACROSS THE SOUTHEAST PRAIRIE COUNTIES...WHILE
THIS IS PLAUSIBLE...IT REDUCES THE OVERALL RISK FOR WIDESPREAD
HEAVY RAIN. SOME SHORT TERM MODELS SUGGEST NEW DEVELOPMENT UPWIND
OF CURRENT ACTIVITY BUT CONFIDENCE IS LOW IS THIS SCENARIO. IF
CURRENT TRENDS HOLD...THE FLASH FLOOD WATCH MAY BE CUT BACK OR
CANCELLED IN ANOTHER UPDATE THIS EVENING. BULK OF THE ACTIVITY
SHOULD MOVE EAST OF THE REGION BY 3AM...IF NOT SOONER...AND THE
AREA BE CLEAR OF ALL HAZARDS BY THAT TIME.
ALLEN
PREV DISCUSSION... /ISSUED 656 PM CDT FRI APR 24 2015/
AVIATION...
/00Z TAFS/
ONGOING CONVECTION JUST TO THE SOUTHEAST OF KDRT WILL CONTINUE TO
MOVE TO THE NORTHEAST. NEW STORMS ARE EXPECTED TO DEVELOP WITHIN
THE NEXT HOUR OR TWO AND APPROACH KSAT AND KSSF AROUND 01Z AND 02Z
OVER KAUS. HIRES SOLUTIONS CLEAR THE KAUS AREA AFTER 04Z BUT KEEP
SHOWERS/STORMS ACROSS SAN ANTONIO THROUGH 05Z SATURDAY. SOME OF
THESE STORMS COULD BE STRONG TO SEVERE AS THEY MOVE ACROSS THE
I-35 CORRIDOR. AT THIS TIME...WILL NOT INCLUDE THUNDERSTORM WIND
GUSTS AS STRONGER STORMS ARE FORECAST TO STAY TO THE SOUTHEAST AND
SOUTH OF THE TERMINALS. MVFR CONDITIONS ARE EXPECTED DURING THE
STORMS PERIOD...BUT CAN NOT RULE OUT IFR CIGS FOR A SHORT PERIOD
OF TIME. AFTER THE STORMS PUSH AWAY OVERNIGHT...WINDS WILL BECOME
LIGHT AND VARIABLE AND REMAIN THROUGH LATE SATURDAY MORNING. VFR
CONDITIONS ARE EXPECTED ACROSS THE I-35 SITES AFTER 13Z WHILE KDRT
REMAINS VFR THROUGH THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 256 PM CDT FRI APR 24 2015/
SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
LOCALLY HEAVY RAINFALL LEADING TO FLASH FLOODING POSSIBLE
TONIGHT ACROSS SOUTHERN AND EASTERN AREAS...
STARTING TO SEE SOME RECOVERY AFTER THE EARLY MORNING MCS. SOME
POCKETS OF CLEARING ARE BEGINNING TO TAKE PLACE ACROSS THE
SOUTHWEST CWA AND FAR WESTERN VAL VERDE COUNTY...AND ALSO SEEING
CONVECTION BEGINNING TO DEVELOP ALONG THE HIGHER TERRAIN IN
MEXICO. ANALYSES INDICATES LOW LEVEL THETA-E RIDGE AXIS ALONG AND
JUST WEST OF THE RIO GRANDE...STILL SOME CIN TO OVERCOME JUST EAST
OF THE RIO GRANDE. WITH ADDITIONAL CLEARING DO EXPECT THE POTENTIAL
FOR SOME STORMS TO CROSS INTO MAVERICK...KINNEY AND/OR VAL VERDE
COUNTIES THROUGH 6 PM.
MODELS ARE IN GENERAL AGREEMENT WITH BROAD MID AND UPPER LEVEL
FORCING INCREASING WEST TO EAST THIS EVENING WITH APPROACH OF
SHORTWAVE...ALONG WITH BROAD ENTRANCE REGION TO UPPER LEVEL JET
STREAK LOCATED OVER THE CWA. SEVERAL HI RES MODELS INDICATE
SCATTERED TO NUMEROUS SHOWERS AND STORMS DEVELOPING EARLY THIS
EVENING SOUTHWEST OF SAN ANTONIO AND SPREADING NORTHEAST THROUGH
THE SOUTHERN AND EASTERN AREAS OF THE CWA THROUGH THE EVENING AND
OVERNIGHT HOURS. IN ADDITION...ARW/NMM/HRRR INDICATING STORMS
DEVELOPING OVER THE SJT CWA CLIPPING FAR NORTHERN AREAS UP NEAR
BURNET.
SUFFICIENT DEEP LAYER SHEAR AND STEEP ELEVATED LAPSE RATES/CAPE
WARRANT THE RISK FOR SOME STRONG TO SEVERE STORMS THIS EVENING...
PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS. BUT THE BIGGER
THREAT MAY BE LOCALLY HEAVY RAINFALL ESPECIALLY ALONG AND SOUTH OF
I-10/US 90. VERY HIGH PWAT AIRMASS STILL POOLED IN THIS REGION...
AND MODEL CONSENSUS OF 1 TO 2 INCHES OF QPF WITH ISOLATED POCKETS
OF 3 TO 4 OCCURRING BETWEEN THE CRP/EWX CWA BOUNDARY AND I-10. A
FLASH FLOOD WATCH HAS BEEN ISSUED FOR A PORTION OF THIS AREA...
COINCIDING WHERE HEAVY RAINFALL HAS ALREADY OCCURRED THE PAST
SEVERAL DAY. THE WATCH GOES AS FAR NORTH AS BASTROP AND LEE
COUNTIES (NOT INCLUDING TRAVIS OR WILLIAMSON)...DESPITE LESSER
AMOUNTS FORECAST IN THIS AREA. THIS IS OUT OF AN ABUNDANCE OF
CAUTION AS SOILS ARE SATURATED OVER MUCH OF THESE AREA...WITH
ONGOING FLOODING PROBLEMS CONTINUING IN BASTROP COUNTY.
PRECIP SHOULD EXIT TO THE EAST OF THE AREA EARLY SATURDAY MORNING.
A WEAK SURFACE BOUNDARY MOVES INTO THE AREA SATURDAY...WITH
SLIGHTLY DRIER AIR ALONG AND WEST OF I-35. A POOL OF MOISTURE
WILL STILL REMAIN ACROSS THE FAR SOUTHEAST ZONES...WHERE ISOLATED
SHOWERS OR THUNDERSTORMS WILL BE A POSSIBILITY SATURDAY AFTERNOON.
RUNYEN
LONG TERM (SUNDAY THROUGH FRIDAY)...THE BOUNDARY MOVES BACK WEST
OF THE I-35 CORRIDOR SUNDAY AND MONDAY...AS AN UPPER LEVEL LOW
DEEPENS ACROSS NEW MEXICO AND THE PANHANDLE. LOW CHANCES FOR
SHOWERS AND STORMS BOTH SUNDAY AND MONDAY ACROSS THE CENTRAL AND
EASTERN CWA AS WEAK FORCING INTERACTS WITH MOISTURE POOLED OVER
THE AREA. EVENTUALLY A COLD FRONT CLEARS THROUGH THE CWA ON
TUESDAY...AND DEEPER NORTHWEST FLOW DEVELOPS OVER THE AREA
WEDNESDAY THROUGH FRIDAY AS THE UPPER LEVEL TROUGH AXIS MOVES
EAST. LOOK FOR MORE SEASONAL TEMPS AND DRY CONDITIONS WEDNESDAY
THROUGH FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 66 86 66 83 60 / 0 30 30 40 10
AUSTIN BERGSTROM INTL AIRPORT 63 85 65 83 60 / - 30 30 40 20
NEW BRAUNFELS MUNI AIRPORT 65 86 67 83 60 / - 30 30 30 10
BURNET MUNI AIRPORT 61 85 62 82 57 / 0 30 30 30 20
DEL RIO INTL AIRPORT 64 90 63 87 60 / - - 20 - -
GEORGETOWN MUNI AIRPORT 63 85 65 82 59 / 0 30 30 40 20
HONDO MUNI AIRPORT 65 88 64 85 60 / - 20 30 20 0
SAN MARCOS MUNI AIRPORT 64 85 66 83 60 / - 30 30 40 10
LA GRANGE - FAYETTE REGIONAL 67 85 69 81 62 / - 30 20 40 30
SAN ANTONIO INTL AIRPORT 67 87 67 85 61 / - 30 30 30 -
STINSON MUNI AIRPORT 66 87 67 84 62 / - 30 30 30 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 5 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING COUNTIES: BASTROP...CALDWELL...DE WITT...FAYETTE...
GONZALES...GUADALUPE...KARNES...LAVACA...LEE...WILSON.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...01
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1134 AM EDT SAT APR 25 2015
.UPDATE...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING A BROAD RIDGING
PATTERN IN PLACE OVER THE EASTERN GULF OF MEXICO AND FLORIDA
PENINSULA. UPPER LEVEL SHORTWAVE PASSING TO OUR NORTH TODAY WILL
ACT TO FLATTEN THE FLOW TO A MORE ZONAL CONFIGURATION BY THIS
EVENING AND THROUGH THE DAY ON SUNDAY. 12Z KTBW SOUNDING PROFILE
SHOWED WE STILL HAVE THE INFLUENCE OF THE RIDGE OVERHEAD WITH A
FAIRLY WELL DEFINED SUBSIDENCE INVERSION SHOWING UP AROUND 800MB.
THE RESULTING CAP IS PRETTY STRONG (AT LEAST OVER THE CENTRAL AND
SOUTHERN ZONES) AND SINCE WE WILL NOT BE SEEING MUCH IN THE WAY OF
HEIGHT FALLS...IT WILL TAKE CONSIDERABLE SURFACE HEATING TO
OVERCOME THIS INHIBITION. THE KJAX SOUNDING STILL SHOWED A BIT OF
A CAP...BUT NOT AS IMPRESSIVE...SO THE INHIBITION DOES WEAKEN
SOMEWHAT TOWARD OUR FAR NORTHERN ZONES.
AT THE SURFACE...
FLOW IS TURNING TO THE SOUTH AND SOUTHWEST AS THE GRADIENT BEGINS
TO TIGHTEN BETWEEN HIGH PRESSURE RIDGING THROUGH THE FLORIDA
STRAITS...AND LOW PRESSURE/WARM FRONTAL FEATURE PASSING WELL TO
OUR NORTH. THE UPPER ENERGY PASSING OVER THE SOUTHEAST CONUS
COMBINED WITH THE LIFT ASSOCIATED WITH THE WARM FRONT IS RESULTING
IN SOME STRONG TO SEVERE THUNDERSTORMS ALONG THE I-10 CORRIDOR OF
FLORIDA UP INTO GA. A TORNADO WATCH IS NOW IN EFFECT AS CLOSE AS
TAYLOR AND LAFAYETTE COUNTIES WITHIN NWS TALLAHASSEE COVERAGE
AREA...AND SUWANNEE AND COLUMBIA COUNTIES IN NWS JACKSONVILLE
COVERAGE AREA. ALTHOUGH THIS WATCH IS IN CLOSE PROXIMITY TO OUR
NORTHERN ZONES...AT THIS TIME WE DO NOT ANTICIPATE AN EXPANSION
FURTHER SOUTH OF THIS WATCH LATER TODAY INTO LEVY/CITRUS/SUMTER
COUNTIES. IN FACT...WE MAY HAVE DIFFICULTY SEEING ANY
THUNDERSTORMS IN OUR FORECAST AREA TODAY.
REST OF TODAY...
SEEING A MIX OF SUN AND CLOUDS ACROSS THE PENINSULA AS THE CU
FIELD BEGINS TO DEVELOP ATOP THE MIXED LAYER. WITH THE MIXING NOW
TAKING PLACE...WINDS ARE BECOMING GUSTY AT TIMES...AND EXPECT
THINGS TO REMAIN GUSTY THROUGH THE REMAINDER OF THE DAYLIGHT
HOURS. ONLY EXPECTING SOME LOW POPS (ISOLATED CONVECTION) TODAY.
SEEING A WEAK BOUNDARY PIVOTING ONSHORE AS WE SPEAK AND WILL
LIKELY SEE A FEW VERY BRIEF AND SHALLOW SHOWERS/SPRINKLES AS IT
QUICKLY TRANSLATES INLAND IN THE STEADY LOW LEVEL FLOW. THE
COMBINATION OF ANY SEA-BREEZE QUICKLY TRANSLATING INLAND AND OUT
OF OUR AREA AND THE CAPPING ENVIRONMENT ALOFT SUGGESTS THAT
CONVECTION WILL NOT BE PLENTIFUL TODAY.
TONIGHT...
MAJORITY OF DIURNAL CONVECTION WILL BE OVER TOWARD THE I-95
CORRIDOR THIS EVENING WITH JUST A SLIGHT CHANCE OF A SHOWER OR
STORM OVER OUR FAR INLAND AREAS...AND THAT THREAT WILL BE ENDING
FAIRLY EARLY. WILL BE A WARM AND HUMID OVERNIGHT PERIOD WITH
STEADY SOUTHWEST FLOW OF THE GULF OF MEXICO. LATE AT NIGHT WILL
SEE A FRONTAL BOUNDARY SAGGING SOUTHWARD ACROSS AL/GA. THE LOW
LEVEL FLOW AHEAD OF THIS BOUNDARY OVER THE NORTHEAST GULF BETWEEN
1000-850MB BECOMES SLIGHTLY CONVERGENT IN NATURE USING STREAMLINE
ANALYSIS. USUALLY SPEAKING IT DOES NOT TAKE MUCH IN THE WAY OF
FORCING/TRIGGER WITHIN SW FLOW TO GET SOME SHOWERS GOING OVER THE
WATER. THEREFORE WOULD EXPECT SCT SHOWERS AND PERHAPS A
THUNDERSTORM TO DEVELOP AFTER MIDNIGHT AND THEN TRANSLATE TOWARD
THE NATURE COAST. MAY EVEN SEE A FEW SHOWERS AS FAR SOUTH AS THE
TAMPA BAY AREA TOWARD DAWN. WILL HAVE LOW END CHANCE POPS FOR THE
NATURE COAST AND NORTHERN MARINE ZONES...AND A SLIGHT CHANCE 20%
POP FURTHER SOUTH TO TAMPA BAY.
SUNDAY...
SURFACE FRONT SETTLES DOWN TOWARD THE I-10 CORRIDOR BY LATE IN THE
DAY. THIS BOUNDARY ALONG WITH SOME SUBTLE UPPER LEVEL SHORTWAVE
ENERGY PASSING THROUGH THE SOUTHEAST CONUS SUGGESTS THE BEST RAIN
CHANCES...IN THE FORM OF SCT SHOWERS / ISOLATED STORMS WILL EXIST
TO THE NORTH OF THE I-4 CORRIDOR. FURTHER SOUTH WHERE THERE WILL
BE LITTLE TO NO SYNOPTIC FORCING FOR LIFT...IT WOULD TAKE THE
SEA-BREEZE TO FORCE CONVECTION...AND EXPECTING THE STRONG
SOUTHWEST FLOW IN THE BL TO PREVENT MUCH OF A DEFINED SEA-BREEZE
FROM FORMING. SO...FORECAST WILL FEATURE CHANCE 30-50% POPS WITH
MOSTLY CLOUDY SKIES NORTH OF THE I-4 CORRIDOR AND SLIGHT CHANCE
20% POPS AND PARTLY CLOUDY FURTHER SOUTH.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS SOUTHWEST AND WEST-CENTRAL FLORIDA
THIS MORNING AND ARE GENERALLY EXPECTED TO CONTINUE THROUGH THE
EVENING HOURS. SOME POTENTIAL FOR A BRIEF PERIOD OF BKN MVFR CIGS
LATER THIS MORNING AS THE CUMULUS FIELDS DEVELOPS...BUT THESE CIGS
WILL QUICKLY RISE ABOVE VFR LEVELS. WINDS ARE BECOMING GUSTY OUT
OF THE SOUTH AND WILL CONTINUE GUSTY THROUGH THE DAYLIGHT HOURS AS
THEY SHIFT MORE TO THE SOUTHWEST FOR THE AFTERNOON AND EVENING.
&&
.MARINE...
THE GRADIENT TIGHTENS TODAY ACROSS THE EASTERN GULF OF MEXICO
BETWEEN LOW PRESSURE PASSING TO OUR NORTH AND A RIDGE OF HIGH
PRESSURE THROUGH THE FLORIDA STRAITS. THE GRADIENT WILL BE
TIGHTEST TO THE NORTH OF ENGLEWOOD WHERE CAUTIONARY LEVEL WINDS
ARE EXPECTED TO DEVELOP TONIGHT INTO EARLY SUNDAY MORNING. WINDS
AND SEAS WILL CONTINUE TO FLIRT WITH CAUTIONARY LEVELS THROUGH THE
DAY ON SUNDAY AS A FRONT SLOWLY APPROACHES FROM THE NORTH. THIS
FRONT WILL LIKELY DROP INTO THE NORTHEAST GULF OF MEXICO AND STALL
DURING THE EARLY PORTION OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 87 77 86 74 / 10 10 30 40
FMY 91 77 90 76 / 10 0 10 20
GIF 90 73 88 72 / 20 10 20 40
SRQ 86 77 85 75 / 0 10 10 40
BKV 89 71 86 69 / 10 10 40 40
SPG 86 77 85 76 / 10 10 20 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL
CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...14/MROCZKA
DECISION SUPPORT...09/RUDE
AREA FORECAST DISCUSSION
NWS MIAMI FL
1005 AM EDT SAT APR 25 2015
.UPDATE...
WILL MAKE SOME MINOR ADJUSTMENTS TO THE MORNING UPDATE, BUT
OVERALL THE FORECAST APPEARS TO BE ON TRACK. SURFACE RIDGE
CURRENTLY IS LOCATED ACROSS THE EXTREME SOUTHERN TIP OF THE
PENINSULA WITH A NEARLY CLOUD FREE SKY ALTHOUGH THE CU FIELD
BEGINNING TO BUILD OVER THE SOUTHERN PORTIONS. THE SKY GRIDS ARE
A LITTLE HIGH SO WILL ADJUST THE FIRST COUPLE OF GRIDS DOWNWARD.
THE 12Z MFL SOUNDING SHOWS A STRONG CAP AT ABOUT 800MB BUT WITH
STRONG HEATING TAKING PLACE THIS MORNING ANY LIFTED PARCEL SHOULD
BE ABLE TO OVERCOME THE CAP BY LATE IN THE AFTERNOON. THE
ATMOSPHERIC PROFILE IS THEN QUITE UNSTABLE ABOVE THIS LAYER WITH
SOME DRIER AIR ALOFT SO PLAN TO MENTION STRONG WIND GUSTS POSSIBLE
WITH THE MORE ROBUST UPDRAFTS. LOW LEVEL FLOW IS VERY WEAK WITH A
GENERAL WEST TO NORTHWEST FLOW ALOFT SO STORM MOTION WILL BE A
SLOW DRIFT TO THE EAST OR SOUTHEAST. THE HRRR HAS BEEN SHOWING
CONVECTION BEGINNING SHORTLY AFTER NOON ALONG THE SEA BREEZE
CONVERGENCE BOUNDARY AND THEN A SLOW DRIFT BACK TOWARDS THE EAST
COAST ESPECIALLY FROM NORTHERN BROWARD INTO PALM BEACH COUNTIES
WHICH MATCHES THE CURRENT FORECAST. SO DO NOT PLAN TO CHANGE THIS
PHILOSOPHY OF THINKING.
KOB
&&
.PREV DISCUSSION... /ISSUED 736 AM EDT SAT APR 25 2015/
AVIATION...
SOUTHEAST SFC WIND FLOW THIS MORNING WILL GRADUALLY VEER TO THE
SOUTH THIS AFTERNOON, THEN TO SW THIS EVENING AS HIGH PRESSURE OFF
THE EAST COAST MOVES AWAY FROM THE AREA AND LOW PRESSURE OVER THE
CENTRAL UNITED STATES STRENGTHENS AND INFLUENCES THE LOCAL
PRESSURE GRADIENT. SEA BREEZES BY 16Z-17Z WILL MODIFY THE WIND
PATTERN, WITH SOLID SW WINDS AT ALL TERMINALS BY AROUND 00Z.
AIRMASS NOT AS MOIST AS THE PAST FEW DAYS, BUT STILL ENOUGH
INSTABILITY FOR SCATTERED SHOWERS/TSTMS MAINLY THIS AFTERNOON.
WESTERLY STEERING FLOW WILL KEEP THE GULF COAST DRY AND PUSH ANY
SHOWERS/TSTMS TOWARDS THE EAST COAST. VFR CONDITIONS SHOULD
PREVAIL, WITH BRIEF PERIODS OF MVFR EAST COAST TERMINALS IN AND
NEAR ANY SHOWERS/TSTMS THIS AFTERNOON. INDICATING VCTS AT PBI-FLL
WHERE COVERAGE IS EXPECTED TO BE GREATER, BUT MAY HAVE TO BE
EXPANDED LATER TODAY TO INCLUDE MIA AREA IF CONVECTION DEVELOPS
FARTHER TO THE SOUTH. /MOLLEDA
PREV DISCUSSION... /ISSUED 429 AM EDT SAT APR 25 2015/
DISCUSSION...
THE MAIN SYNOPTIC FEATURES ACROSS THE REGION INCLUDE A WEAK AREA
OF HIGH PRESSURE JUST OFF THE GEORGIA COASTLINE AND AN UPPER LEVEL
RIDGE ACROSS THE CENTRAL GULF AND ACROSS MUCH OF THE FLORIDA
PENINSULA. THESE SYNOPTIC FEATURES RESULT IN GENERALLY EASTERLY
WINDS ACROSS THE REGION EARLY THIS MORNING WITH STABLE WEATHER AS
RECENT SATELLITE IMAGERY INDICATES NEARLY CLEAR SKIES AND RECENT
RADAR RETURNS INDICATE ONLY ISOLATED SHOWERS ACROSS THE NORTHERN
KEYS.
FOR TODAY...WINDS ACROSS THE REGION ARE EXPECTED TO BECOME MORE
SOUTHERLY AS THE DAY PROGRESS. THE UPPER LEVEL RIDGE ACROSS THE
REGION WILL CONTINUE TO PLAY A STABILIZING ROLE FOR TODAY...BUT
FORECAST SOUNDINGS INDICATE THAT THE PWAT COULD REMAIN AROUND 1.7
INCHES. SO WITH AVAILABLE LOW LEVEL MOISTURE AND SEA BREEZES
DEVELOPING THIS AFTERNOON...GUIDANCE SUGGESTS THAT SURFACE
CONVERGENCE AND THE POTENTIAL FOR CONVECTION SHOULD BE ACROSS THE
EASTERN HALF OF THE PENINSULA THIS AFTERNOON. THUS THE FORECAST
HAS A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY CONCENTRATED
ACROSS THE EASTERN AND NORTHERN PENINSULA WITH THE GREATEST
COVERAGE EXPECTED ACROSS PALM BEACH COUNTY. STRONG THUNDERSTORMS
ARE NOT EXPECTED TODAY WITH THE STABILIZING EFFECT OF THE UPPER
LEVEL RIDGE.
FOR SUNDAY...SURFACE HIGH PRESSURE WILL PREVAIL ACROSS THE EASTERN
GULF AS A DEVELOPING SURFACE LOW AND COLD FRONT IS FORECAST TO
ENTER THE SOUTHEASTERN STATES. THIS SYNOPTIC SET UP WILL HAVE DEEP
LAYERED MOISTURE REMAINING NORTH OF SOUTH FLORIDA WITH A GENERALLY
STABLE LOCAL ATMOSPHERE. WITH SOUTHWESTERLY WINDS ACROSS THE
REGION ISOLATED SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS THE
NORTHEASTERN PORTION OF THE SOUTH FLORIDA PENINSULA.
FOR MONDAY INTO EARLY NEXT WEEK...BY MONDAY THE AFOREMENTIONED
SURFACE LOW IS FORECAST TO BE ROUGHLY OFF THE COAST OF
JACKSONVILLE WITH THE TRAILING COLD FRONT ACROSS NORTH FLORIDA.
THIS WILL BRING MOISTURE BACK TO THE REGION WITH THE UPPER LEVEL
RIDGE STARTING TO ERODE WITH A CHANCE OF SHOWERS AND THUNDERSTORMS
FORECAST. THE GUIDANCE CONSENSUS INDICATES A BROAD SURFACE LOW
ENTERING THE NORTHERN GULF ON TUESDAY AND THEN BY WEDNESDAY THE
LOW IS FORECAST TO DEEPEN AND SHIFT EASTWARD TO NORTH FLORIDA
WHILE A MID TO UPPER LEVEL TROUGH DIGS INTO THE NORTHERN GULF.
THIS FORECAST SCENARIO WILL MAINTAIN A CONSIDERABLE CHANCE OF
CONVECTION ACROSS SOUTH FLORIDA AND ADJACENT WATERS WITH SCATTERED
TO NUMEROUS SHOWERS AND THUNDERSTORMS FORECAST TUESDAY AND
WEDNESDAY. A GRADUAL DRYING TREND IS FORECAST INTO THE LATER PART
OF THE WEEK.
MARINE...
WINDS ACROSS THE REGIONAL WATERS ARE GENERALLY EASTERLY AROUND 10
KNOTS EARLY THIS MORNING BUT ARE FORECAST TO BECOME MORE
SOUTHERLY BY THE AFTERNOON WITH GULF SEAS 2 FEET OR LESS AND THE
ATLANTIC SEAS 2 TO 4 FEET. TONIGHT INTO SUNDAY WINDS ARE FORECAST
TO TRANSITION TO SOUTHWESTERLY DIRECTION WITH ATLANTIC WINDS IN
THE 12 TO 17 KNOT RANGE AND IN THE 10 TO 15 KNOT RANGE FOR THE
ATLANTIC WATERS.
UNCERTAINTY WILL CONTINUE IN THE WIND FORECAST IN THE EXTENDED
PERIODS WITH THE GUIDANCE FORECASTING A BROAD SURFACE LOW
ENTERING THE NORTHERN GULF ON TUESDAY AND THEN BY WEDNESDAY THE
LOW IS FORECAST TO DEEPEN AND SHIFT EASTWARD INTO NORTH FLORIDA.
WINDS IN THE 15 TO 20 KNOT RANGE MAY BE POSSIBLE BY WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 75 93 75 / 30 10 20 20
FORT LAUDERDALE 88 78 93 77 / 20 0 20 20
MIAMI 91 76 93 77 / 20 0 10 10
NAPLES 90 78 89 75 / 10 0 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1130 AM EDT SAT APR 25 2015
.UPDATE...
ISSUED AT 1130 AM EDT SAT APR 25 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE A SWATH OF SHOWERS
MOVING THROUGH TO THE NORTHEAST ACROSS EASTERN KENTUCKY. AT THIS
TIME...THE WARM FRONT IS DEVELOPING AND SLOWLY MOVING NORTH AND IS
POSITIONED JUST NORTH ALONG THE KY/TN BORDER. CLOUD COVER AT THIS
TIME IS QUITE EXTENSIVE ACROSS THE AREA...THOUGH...SOME PEAKS OF
CLEARING ARE OCCURRING TO THE WEST AND A FEW PEAKS TO THE SOUTH.
HOWEVER...ONGOING CONVECTION ALONG THE GULF COAST SEEMS TO BE
KEEPING CLOUD COVER STREAMING NORTHWARD INTO THE AREA THIS
AFTERNOON. HAVE TIMED A BIT OF CLEARING TO OCCUR OVER SOUTHEAST
KENTUCKY BUT IF THE CLOUD COVER MOVING UP FROM THE SOUTH
CONTINUES...SEVERE CONVECTION WILL BE DRASTICALLY LIMITED INTO
THIS AFTERNOON AND EVENING. LATER THIS EVENING...THE HRRR HINTS AT
AN MCS DEVELOPMENT AND MOVING SOUTH SOUTHEAST INTO THE AREA ALONG
WITH THE SURFACE LOW BY 00Z TONIGHT. AT THIS TIME...THE EVENT MAY
BE TRANSITIONING INTO A HYDRO EVENT. HAVE UPDATED THE ZFP TO TIME
THE THREAT OF SEVERE WEATHER THIS EVENING AND THE PROGRESSION OF
THE WARM FRONT THROUGH THE DAY. IT GOES WITHOUT SAYING THAT THE
NEXT FEW HOURS WILL SAY ALOT ABOUT WHAT TRANSPIRES LATER THIS
AFTERNOON AND INTO THE EVENING.
UPDATE ISSUED AT 13 AM EDT SAT APR 25 2015
BLENDED EARLY MORNING OBS INTO THE FORECAST. NO SUBSTANTIAL
CHANGES WERE MADE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT SAT APR 25 2015
AN ACTIVE PERIOD IS IN STORE...WITH EVENTS JUST BEGINNING TO
UNFOLD. AN AREA OF SHOWERS IS EXPECTED TO DEVELOP AND MOVE NE OVER
THE REGION THIS MORNING. HOWEVER...IT IS BEHIND SCHEDULE AS BASED
ON THE 00Z MODELS...WITH A CONVECTIVE SYSTEM OVER MS AND AL
POSSIBLY FOILING THE OUTCOME. THE LATEST HRRR MODEL SUGGESTS IT
WILL STILL HAPPEN...BUT MAY BE MORE FOCUSED ON OUR NORTHERN
COUNTIES.
ONCE THIS PASSES...IT WILL BE A WAITING GAME FOR ADDITIONAL
CONVECTION TO DEVELOP DURING THE AFTERNOON AND EVENING AS A STORM
SYSTEM APPROACHES FROM THE WEST...ALONG A FRONTAL BOUNDARY DRAPED
ACROSS OUR AREA. IT STILL APPEARS THERE WILL BE LARGE SURFACE
BASED INSTABILITY PRESENT IN OUR SOUTHWEST COUNTIES...WITH WEAKER
AND MORE ELEVATED INSTABILITY FURTHER NORTHEAST. SHEAR WILL BE
MORE THAN SUFFICIENT TO SUPPORT ORGANIZED CONVECTION. DRY MID
LEVEL AIR IS ALSO EXPECTED IN OUR SW. THIS WILL PRESENT A THREAT
OF SEVERE WEATHER OVER OUR SW...WITH SUPER CELLS POSSIBLY
PRODUCING LARGE HAIL AND HIGH WINDS...AND A SECONDARY THREAT OF
TORNADOES. EXCESSIVE RAINFALL IS ALSO A CONCERN WITH TRAINING OF
CELLS ALONG THE FRONTAL BOUNDARY. WHERE THIS MAY SET UP IS STILL
UNCERTAIN. ANY HYDRO PROBLEMS LIKELY WOULD NOT ARISE UNTIL THIS
EVENING...AND HAVE OPTED TO LET DAY SHIFT EXAMINE THE 12Z RUN
BEFORE MAKING A DECISION ON A FFA.
THE FRONTAL BOUNDARY WILL MOVE TO OUR SOUTH AS LOW PRESSURE MOVES
EAST THROUGH THE REGION TONIGHT. ANY LINGERING SHOWERS WILL END ON
SUNDAY MORNING AND CLOUDS WILL BREAK UP DURING THE DAY FROM NW TO
SE AS DRY AIR MOVES IN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 AM EDT SAT APR 25 2015
THE MODELS WERE IN GOOD AGREEMENT IN THE EXTENDED. THE PERIOD IS
SET TO BEGIN WITH A LARGE RIDGE OF HIGH PRESSURE MOVE OUT OF THE
NORTH CENTRAL PLAINS AND ACROSS THE LOWER GREAT LAKES AND OHIO AND
TENNESSEE VALLEY REGIONS SUNDAY NIGHT THROUGH TUESDAY. THE PATTERN
IS THEN FORECAST TO CHANGE TUESDAY NIGHT AND WEDNESDAY...AS BOTH
NORTHERN AND SOUTHERN STREAM WEATHER SYSTEMS MAKE THEIR WAY ACROSS
THE GREAT LAKES AND GULF COAST REGIONS. THE SOUTHERN STREAM SYSTEM
APPEARS TO BE THE STRONGER OF THE TWO...AND THEREFORE WOULD HAVE
TO GREATER INFLUENCE ON AREA WEATHER MID WEEK. AS IT STANDS...A
ROUGHLY 60 40 BLEND OF THE ECMWF AND GFS MODELS WAS USED TO CREATE
THE FORECAST FROM TUESDAY NIGHT ONWARD. THE SOUTHERN STREAM
TROUGH IS PROGGED TO BRING MOISTURE OFF THE GULF OF MEXICO
NORTHWARD INTO CENTRAL AND EASTERN KENTUCKY WEDNESDAY AND
WEDNESDAY NIGHT. AS THIS OCCURS...THE NORTHERN STREAM SYSTEM IS
FORECAST TO DIVE SOUTHWARD AND PHASE WITH THE TENNESSEE VALLEY
SOUTHEASTERN CONUS LOW. THE GFS DOES DIFFER SLIGHTLY FROM THE
ECMWF MODEL DURING THIS PERIOD...AS ITS NORTHERN STREAM LOW PUSHES
ON EASTWARD INTO NEW ENGLAND...AS OPPOSED TO PHASING WITH THE
SOUTHERN SYSTEM...AS THE ECMWF IS DEPICTING. THAT BEING
SAID...THIS IS WHERE THE USUALLY MORE CONSISTENT ECMWF MODEL
SOLUTION WAS FAVORED. THERE WILL BE A CHANCE OF RAIN IN THE
FORECAST FOR THE ENTIRE AREA FROM LATE TUESDAY NIGHT THROUGH
THURSDAY NIGHT. HOWEVER...DUE TO THE DIFFERING MODEL
SOLUTIONS...DECIDED TO STAY WITH SLIGHT CHANCE TO CHANCE
POPS...WITH 40 BEING THE HIGH END DURING THE WET PERIOD. FRIDAY
AND FRIDAY NIGHT LOOK TO BE DRY AS THE SOUTHERN STREAM WEATHER
SYSTEM EXITS TO OUR EAST AND ANOTHER RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE SOUTHERN AND SOUTHEASTERN CONUS.
TEMPERATURES NEXT WEEK WILL LIKELY BE BELOW NORMAL THROUGH
THURSDAY...DUE TO THE INFLUENCE OF CLOUD COVER AND PRECIPITATION
AND THE FACT THAT THIS WEEKENDS TEMPERATURES WILL ALSO REMAIN WELL
BELOW NORMAL DUE WIDESPREAD CLOUD COVER AND PRECIPITATION. WHAT
THIS AMOUNTS TO IS THE ATMOSPHERE WILL STARTING OFF BEHIND THE
EIGHT BALL TO START THE WEEK TEMPERATURE WISE...MAKING IT
DIFFICULT FOR THINGS TO WARM UP AS MUCH AS NORMAL DUE TO THE SHORT
BREAK BETWEEN WEATHER SYSTEMS. HIGHS ON FRIDAY SHOULD BE RIGHT
AROUND NORMAL ACROSS THE ENTIRE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 813 AM EDT SAT APR 25 2015
ALTHOUGH SHOWERS WERE MOVING THROUGH THE REGION...VFR CONDITIONS
WERE STILL PRESENT AT MOST LOCATIONS AT TAF ISSUANCE. THE
EXCEPTION WAS IN THE FAR SW PART OF THE FORECAST AREA AROUND KEKQ
AND KSME...WHERE MVFR CEILINGS HAD DEVELOPED. THE MVFR CONDITIONS
WILL OVERSPREAD THE AREA FROM SW TO NE THIS MORNING...WITH SOME
IFR POSSIBLE AT TIMES. THROUGH THE AFTERNOON...LARGELY MVFR CAN BE
EXPECTED TO PERSIST...EXCEPT FOR IFR FROM AROUND THE MOUNTAIN
PARKWAY NORTHWARD. MOST OF THE SHOWERS WILL TAPER OFF FOR A TIME
EARLY THIS AFTERNOON...BUT A REDEVELOPMENT OF SHOWERS AND
THUNDERSTORMS IS EXPECTED LATE IN THE DAY AND THIS EVENING. SOME
OF THESE MAY CONTAIN LARGE HAIL AND HIGH WINDS. A COLD FRONT WILL
SINK SOUTH THROUGH THE AREA TONIGHT...AND PRECIPITATION WILL START
TO TAPER OFF LATE. HOWEVER...MVFR AND LOCALIZED IFR WILL LINGER
THROUGH THE END OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...HAL
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
932 AM EDT Sat Apr 25 2015
...Forecast Update...
Updated 930 AM EDT Sat Apr 25 2015
Latest guidance including the latest SPC Day 1 Outlook continues to
trend the severe threat slightly to the north. No big changes have
been made to the grids, but have tried to trend the pop forecast a
bit towards the latest hi-res model guidance. Also nudged the area
where severe storms are mentioned slightly further to the north. The
ongoing precipitation has not had any lightning associated with it
so far. However, think we could still see some isolated flashes
through the late morning hours.
Updated 621 AM EDT Sat Apr 25 2015
No major changes needed to the forecast this morning, as it is
largely on track. Still expecting rain showers to continue to
blossom over the region, especially along and north of I-64 this
morning. This is all in response to a low-level jet and isentropic
ascent veering into the region. May see a few rumbles of thunder
especially as we get into the late morning hours, but no severe
weather is expected through noon.
The 06Z NAM has come in further north with the warm frontal
placement late this afternoon, which would bring the I-64 corridor
more into play for severe potential. However, the latest runs of
the HRRR continue to show the warm front stalling south of I-64 and
very close to the current forecast position. Given the HRRR has a
decent handle on ongoing convection, and the support of the other
hi-res guidance in regards to expected frontal position this
afternoon, see no need to adjust things further north based on the
06Z NAM quite yet. Will continue to monitor trends through the
morning hours and especially the 12Z guidance suite.
.SHORT TERM (Now through Saturday Night)...
Issued at 345 AM EDT Sat Apr 25 2015
...Severe Weather Likely This Afternoon and Evening...
Overview
========
The current synoptic setup features a split-flow regime across the
CONUS. The Ohio Valley will be affected by a PV anomaly currently
across eastern Kansas and western MO, which will push through the
region late this afternoon into tonight.
In response to the ejecting PV anomaly out of the southwest flow
aloft, a surface low has formed across portions of eastern KS. This
low will slide east today, but will begin to fill as the overall
system encounters confluent flow over the Ohio Valley. A very sharp
warm front associated with this low pressure system will develop
across the Ohio Valley today.
This Morning
============
With the ejecting wave, isentropic ascent has increased across the
region this morning. This has led to showers breaking out across
the Ohio Valley, and the radar should continue to blossom through
the morning hours as a low-level jet of 40-50 knots veers into the
region towards sunrise. Forecast soundings show limited elevated
instability, so severe weather is not expected. Just some showers
with a few embedded rumbles of thunder appears likely.
This Afternoon/Evening
======================
The placement of the aforementioned sharp warm front will be
absolutely critical to how far north the severe weather threat gets
this afternoon/evening. The 25/00Z guidance shifted this front
south just a bit from previous runs, which would take much of the
I-64 corridor out of the main severe risk. Will cautiously trend
the forecast towards this more southern solution given the support
on almost guidance members, but still am a bit weary this front
could end up surging further north, especially if there is less
showers/storm coverage this morning than expected (less convective
enhancement to the front). This warm front will be the main player
that we will continue to monitor through the day.
At this point, expect the front to align itself roughly along a line
from Owensboro, to north of Elizabethtown, over towards Lebanon
by late this afternoon. To the south of it, a warm and unstable
airmass is likely to materialize given temperatures rising to near
80 and dewpoints in the middle 60s. This low-level environment
coupled with very steep lapse rates aloft will support MLCAPEs
anywhere from 1500-3000 J/kg, with much of that CAPE residing within
the hail growth zone (-10 to -30C).
The evolution of the convection could be rather complex. There
seems to be a decent signal in the hi-res guidance that the strong
warm front may lead to convective initiation, which will likely be
initially discrete in nature. Given 0-6km shear well over 50 knots,
these will be supercellular, if they are to form. The aforementioned
instability coupled with deep-layer shear will lead to a large hail
threat, with golf ball to even baseball-sized hail not out of the
question in some of these storms. Bunker`s RM storm motion vectors
place the motion of these potential supercells almost parallel to
the warm front, which is worrisome because any storm that forms
along this front will have access to enhanced helicity, given the
backed surface winds. Therefore, think there is an enhanced tornado
threat right along this boundary wherever it happens to set up,
perhaps more of a threat than SPC is currently highlighting with
their 5% Tornado risk.
Further south (across far southern KY, near TN border), strong
mixing coupled with the fact that the surface low will be filling
will lead to more veered surface winds, which should cut down
somewhere on the effective SRH. However, with westerly low-level
jet expected to strengthen towards 26/00Z, hodographs will be
long/curved enough to support an isolated tornado threat early this
evening in areas south of the warm front. Coverage of these storms
not tied to the warm front will likely be rather isolated, given a
lack of convergence and the presence of a weak cap in the warm
sector.
By a bit later this evening, the actual surface low will push into
west-central KY. Near the triple point of this low, enhanced
convergence will likely lead to a more concentrated area of
convection, perhaps a mix of bowing segments and supercells which
will push into the I-65 corridor toward 02-04Z. By this time,
daytime instability should be beginning to wane, but still think
this second round will carry a severe threat of large hail, damaging
winds, and isolated tornadoes as it pushes southeast across
south-central KY.
Bust Potential
==============
There remains some potential bust factors with this setup. The
first and most obvious, is the morning convection. We will need
this to clear out and some sunshine to break out south of the warm
front this afternoon for us to destabilize. Given the general
guidance agreement, do have pretty high confidence this will occur
and we will become quite unstable across southern KY late this
afternoon.
The other potential bust factor will if discrete development will
occur late this afternoon/early evening. Warm fronts can be tricky
in initiating surface-based convection, so we could go through the
day not seeing much becoming sustained along the front. In
addition, the weak cap could hold through the rest of the warm
sector giving very little coverage of discrete convection until the
more concentrated line of storms approaches with the surface low
well after peak heating.
Summary
=======
While there is bust potential, have fairly high confidence in severe
weather this afternoon and evening. Think the main threats will be
hail and damaging winds, but an enhanced tornado threat will be
found right along the warm front. This is something we will
continue to monitor closely this afternoon. Even north of the warm
front in Lexington and Louisville, forecast soundings show quite a
bit of elevated instability above the stable boundary layer, so
severe hail will certainly be a possibility even in areas north of
the warm front.
.LONG TERM (Sunday through Friday)...
Issued at 230 AM EDT Sat Apr 25 2015
Cool and mostly dry conditions are expected from Sunday most of the
way through next week. Upper pattern looks fairly blocky as the main
player is an eastern CONUS trof that keeps getting reinforced.
Around mid-week a bowling-ball closed low in the southern stream
will push across the Deep South, with precip chances in the Ohio
Valley Wednesday and Wednesday night. Timing is still a bit
uncertain, and the ECMWF is more bullish in phasing this system with
a northern stream disturbance, so will just paint low-end chance
POPs for Wednesday and Wednesday night. Temps will run below climo
for most of this period.
Toward the end of the week, upper ridging over the Plains starts to
build into the Ohio Valley. Look for dry weather and exceedingly
pleasant temps with highs in the 70s and lows either side of 50 just
in time for the first weekend in May.
&&
.AVIATION (12Z TAF Update)...
Updated at 651 AM EDT Sat Apr 25 2015
Deteriorating conditions will push in through the TAF period, as an
area of low pressure approaches from the west. Showers will
continue to expand in coverage this morning, bringing MVFR vsbys at
cigs at times to all terminals. Will leave in VCTS wording given
some marginal elevated instability, but think any thunderstorm
activity will be rather isolated through the morning hours.
A warm front will sharpen and lift northeast into the area today.
Just north of this front, a period of IFR cigs can be expected at
all sites. The latest guidance suite continues to suggest this
front will likely stall just to the south of KSDF and KLEX, meaning
low cigs may persist in these locations through much of the day,
especially at KLEX. KBWG will likely scour out this afternoon and
mix down SSW wind gusts around 25 knots. Late this afternoon into
this evening, severe thunderstorms are expected to break out over
central KY, mainly affecting KBWG. However, there is enough
elevated instability to warrant VCTS wording at KSDF and KLEX as
well with this activity. Winds will turn more northerly late in the
TAF period as the area of low pressure pushes to the southeast.
12Z TAF Forecaster Confidence
=============================
Ceilings : Medium
Visibilities: Medium
Winds : Low at KSDF and KLEX
=============================
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........EER/KJD
Short Term.....KJD
Long Term......RAS
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS JACKSON KY
813 AM EDT SAT APR 25 2015
.UPDATE...
ISSUED AT 13 AM EDT SAT APR 25 2015
BLENDED EARLY MORNING OBS INTO THE FORECAST. NO SUBSTANTIAL
CHANGES WERE MADE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT SAT APR 25 2015
AN ACTIVE PERIOD IS IN STORE...WITH EVENTS JUST BEGINNING TO
UNFOLD. AN AREA OF SHOWERS IS EXPECTED TO DEVELOP AND MOVE NE OVER
THE REGION THIS MORNING. HOWEVER...IT IS BEHIND SCHEDULE AS BASED
ON THE 00Z MODELS...WITH A CONVECTIVE SYSTEM OVER MS AND AL
POSSIBLY FOILING THE OUTCOME. THE LATEST HRRR MODEL SUGGESTS IT
WILL STILL HAPPEN...BUT MAY BE MORE FOCUSED ON OUR NORTHERN
COUNTIES.
ONCE THIS PASSES...IT WILL BE A WAITING GAME FOR ADDITIONAL
CONVECTION TO DEVELOP DURING THE AFTERNOON AND EVENING AS A STORM
SYSTEM APPROACHES FROM THE WEST...ALONG A FRONTAL BOUNDARY DRAPED
ACROSS OUR AREA. IT STILL APPEARS THERE WILL BE LARGE SURFACE
BASED INSTABILITY PRESENT IN OUR SOUTHWEST COUNTIES...WITH WEAKER
AND MORE ELEVATED INSTABILITY FURTHER NORTHEAST. SHEAR WILL BE
MORE THAN SUFFICIENT TO SUPPORT ORGANIZED CONVECTION. DRY MID
LEVEL AIR IS ALSO EXPECTED IN OUR SW. THIS WILL PRESENT A THREAT
OF SEVERE WEATHER OVER OUR SW...WITH SUPER CELLS POSSIBLY
PRODUCING LARGE HAIL AND HIGH WINDS...AND A SECONDARY THREAT OF
TORNADOES. EXCESSIVE RAINFALL IS ALSO A CONCERN WITH TRAINING OF
CELLS ALONG THE FRONTAL BOUNDARY. WHERE THIS MAY SET UP IS STILL
UNCERTAIN. ANY HYDRO PROBLEMS LIKELY WOULD NOT ARISE UNTIL THIS
EVENING...AND HAVE OPTED TO LET DAY SHIFT EXAMINE THE 12Z RUN
BEFORE MAKING A DECISION ON A FFA.
THE FRONTAL BOUNDARY WILL MOVE TO OUR SOUTH AS LOW PRESSURE MOVES
EAST THROUGH THE REGION TONIGHT. ANY LINGERING SHOWERS WILL END ON
SUNDAY MORNING AND CLOUDS WILL BREAK UP DURING THE DAY FROM NW TO
SE AS DRY AIR MOVES IN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 AM EDT SAT APR 25 2015
THE MODELS WERE IN GOOD AGREEMENT IN THE EXTENDED. THE PERIOD IS
SET TO BEGIN WITH A LARGE RIDGE OF HIGH PRESSURE MOVE OUT OF THE
NORTH CENTRAL PLAINS AND ACROSS THE LOWER GREAT LAKES AND OHIO AND
TENNESSEE VALLEY REGIONS SUNDAY NIGHT THROUGH TUESDAY. THE PATTERN
IS THEN FORECAST TO CHANGE TUESDAY NIGHT AND WEDNESDAY...AS BOTH
NORTHERN AND SOUTHERN STREAM WEATHER SYSTEMS MAKE THEIR WAY ACROSS
THE GREAT LAKES AND GULF COAST REGIONS. THE SOUTHERN STREAM SYSTEM
APPEARS TO BE THE STRONGER OF THE TWO...AND THEREFORE WOULD HAVE
TO GREATER INFLUENCE ON AREA WEATHER MID WEEK. AS IT STANDS...A
ROUGHLY 60 40 BLEND OF THE ECMWF AND GFS MODELS WAS USED TO CREATE
THE FORECAST FROM TUESDAY NIGHT ONWARD. THE SOUTHERN STREAM
TROUGH IS PROGGED TO BRING MOISTURE OFF THE GULF OF MEXICO
NORTHWARD INTO CENTRAL AND EASTERN KENTUCKY WEDNESDAY AND
WEDNESDAY NIGHT. AS THIS OCCURS...THE NORTHERN STREAM SYSTEM IS
FORECAST TO DIVE SOUTHWARD AND PHASE WITH THE TENNESSEE VALLEY
SOUTHEASTERN CONUS LOW. THE GFS DOES DIFFER SLIGHTLY FROM THE
ECMWF MODEL DURING THIS PERIOD...AS ITS NORTHERN STREAM LOW PUSHES
ON EASTWARD INTO NEW ENGLAND...AS OPPOSED TO PHASING WITH THE
SOUTHERN SYSTEM...AS THE ECMWF IS DEPICTING. THAT BEING
SAID...THIS IS WHERE THE USUALLY MORE CONSISTENT ECMWF MODEL
SOLUTION WAS FAVORED. THERE WILL BE A CHANCE OF RAIN IN THE
FORECAST FOR THE ENTIRE AREA FROM LATE TUESDAY NIGHT THROUGH
THURSDAY NIGHT. HOWEVER...DUE TO THE DIFFERING MODEL
SOLUTIONS...DECIDED TO STAY WITH SLIGHT CHANCE TO CHANCE
POPS...WITH 40 BEING THE HIGH END DURING THE WET PERIOD. FRIDAY
AND FRIDAY NIGHT LOOK TO BE DRY AS THE SOUTHERN STREAM WEATHER
SYSTEM EXITS TO OUR EAST AND ANOTHER RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE SOUTHERN AND SOUTHEASTERN CONUS.
TEMPERATURES NEXT WEEK WILL LIKELY BE BELOW NORMAL THROUGH
THURSDAY...DUE TO THE INFLUENCE OF CLOUD COVER AND PRECIPITATION
AND THE FACT THAT THIS WEEKENDS TEMPERATURES WILL ALSO REMAIN WELL
BELOW NORMAL DUE WIDESPREAD CLOUD COVER AND PRECIPITATION. WHAT
THIS AMOUNTS TO IS THE ATMOSPHERE WILL STARTING OFF BEHIND THE
EIGHT BALL TO START THE WEEK TEMPERATURE WISE...MAKING IT
DIFFICULT FOR THINGS TO WARM UP AS MUCH AS NORMAL DUE TO THE SHORT
BREAK BETWEEN WEATHER SYSTEMS. HIGHS ON FRIDAY SHOULD BE RIGHT
AROUND NORMAL ACROSS THE ENTIRE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 813 AM EDT SAT APR 25 2015
ALTHOUGH SHOWERS WERE MOVING THROUGH THE REGION...VFR CONDITIONS
WERE STILL PRESENT AT MOST LOCATIONS AT TAF ISSUANCE. THE
EXCEPTION WAS IN THE FAR SW PART OF THE FORECAST AREA AROUND KEKQ
AND KSME...WHERE MVFR CEILINGS HAD DEVELOPED. THE MVFR CONDITIONS
WILL OVERSPREAD THE AREA FROM SW TO NE THIS MORNING...WITH SOME
IFR POSSIBLE AT TIMES. THROUGH THE AFTERNOON...LARGELY MVFR CAN BE
EXPECTED TO PERSIST...EXCEPT FOR IFR FROM AROUND THE MOUNTAIN
PARKWAY NORTHWARD. MOST OF THE SHOWERS WILL TAPER OFF FOR A TIME
EARLY THIS AFTERNOON...BUT A REDEVELOPMENT OF SHOWERS AND
THUNDERSTORMS IS EXPECTED LATE IN THE DAY AND THIS EVENING. SOME
OF THESE MAY CONTAIN LARGE HAIL AND HIGH WINDS. A COLD FRONT WILL
SINK SOUTH THROUGH THE AREA TONIGHT...AND PRECIPITATION WILL START
TO TAPER OFF LATE. HOWEVER...MVFR AND LOCALIZED IFR WILL LINGER
THROUGH THE END OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...HAL
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
652 AM EDT Sat Apr 25 2015
...Updated Aviation Discussion...
...Forecast Update...
Updated 621 AM EDT Sat Apr 25 2015
No major changes needed to the forecast this morning, as it is
largely on track. Still expecting rain showers to continue to
blossom over the region, especially along and north of I-64 this
morning. This is all in response to a low-level jet and isentropic
ascent veering into the region. May see a few rumbles of thunder
especially as we get into the late morning hours, but no severe
weather is expected through noon.
The 06Z NAM has come in further north with the warm frontal
placement late this afternoon, which would bring the I-64 corridor
more into play for severe potential. However, the latest runs of
the HRRR continue to show the warm front stalling south of I-64 and
very close to the current forecast position. Given the HRRR has a
decent handle on ongoing convection, and the support of the other
hi-res guidance in regards to expected frontal position this
afternoon, see no need to adjust things further north based on the
06Z NAM quite yet. Will continue to monitor trends through the
morning hours and especially the 12Z guidance suite.
.SHORT TERM (Now through Saturday Night)...
Issued at 345 AM EDT Sat Apr 25 2015
...Severe Weather Likely This Afternoon and Evening...
Overview
========
The current synoptic setup features a split-flow regime across the
CONUS. The Ohio Valley will be affected by a PV anomaly currently
across eastern Kansas and western MO, which will push through the
region late this afternoon into tonight.
In response to the ejecting PV anomaly out of the southwest flow
aloft, a surface low has formed across portions of eastern KS. This
low will slide east today, but will begin to fill as the overall
system encounters confluent flow over the Ohio Valley. A very sharp
warm front associated with this low pressure system will develop
across the Ohio Valley today.
This Morning
============
With the ejecting wave, isentropic ascent has increased across the
region this morning. This has led to showers breaking out across
the Ohio Valley, and the radar should continue to blossom through
the morning hours as a low-level jet of 40-50 knots veers into the
region towards sunrise. Forecast soundings show limited elevated
instability, so severe weather is not expected. Just some showers
with a few embedded rumbles of thunder appears likely.
This Afternoon/Evening
======================
The placement of the aforementioned sharp warm front will be
absolutely critical to how far north the severe weather threat gets
this afternoon/evening. The 25/00Z guidance shifted this front
south just a bit from previous runs, which would take much of the
I-64 corridor out of the main severe risk. Will cautiously trend
the forecast towards this more southern solution given the support
on almost guidance members, but still am a bit weary this front
could end up surging further north, especially if there is less
showers/storm coverage this morning than expected (less convective
enhancement to the front). This warm front will be the main player
that we will continue to monitor through the day.
At this point, expect the front to align itself roughly along a line
from Owensboro, to north of Elizabethtown, over towards Lebanon
by late this afternoon. To the south of it, a warm and unstable
airmass is likely to materialize given temperatures rising to near
80 and dewpoints in the middle 60s. This low-level environment
coupled with very steep lapse rates aloft will support MLCAPEs
anywhere from 1500-3000 J/kg, with much of that CAPE residing within
the hail growth zone (-10 to -30C).
The evolution of the convection could be rather complex. There
seems to be a decent signal in the hi-res guidance that the strong
warm front may lead to convective initiation, which will likely be
initially discrete in nature. Given 0-6km shear well over 50 knots,
these will be supercellular, if they are to form. The aforementioned
instability coupled with deep-layer shear will lead to a large hail
threat, with golf ball to even baseball-sized hail not out of the
question in some of these storms. Bunker`s RM storm motion vectors
place the motion of these potential supercells almost parallel to
the warm front, which is worrisome because any storm that forms
along this front will have access to enhanced helicity, given the
backed surface winds. Therefore, think there is an enhanced tornado
threat right along this boundary wherever it happens to set up,
perhaps more of a threat than SPC is currently highlighting with
their 5% Tornado risk.
Further south (across far southern KY, near TN border), strong
mixing coupled with the fact that the surface low will be filling
will lead to more veered surface winds, which should cut down
somewhere on the effective SRH. However, with westerly low-level
jet expected to strengthen towards 26/00Z, hodographs will be
long/curved enough to support an isolated tornado threat early this
evening in areas south of the warm front. Coverage of these storms
not tied to the warm front will likely be rather isolated, given a
lack of convergence and the presence of a weak cap in the warm
sector.
By a bit later this evening, the actual surface low will push into
west-central KY. Near the triple point of this low, enhanced
convergence will likely lead to a more concentrated area of
convection, perhaps a mix of bowing segments and supercells which
will push into the I-65 corridor toward 02-04Z. By this time,
daytime instability should be beginning to wane, but still think
this second round will carry a severe threat of large hail, damaging
winds, and isolated tornadoes as it pushes southeast across
south-central KY.
Bust Potential
==============
There remains some potential bust factors with this setup. The
first and most obvious, is the morning convection. We will need
this to clear out and some sunshine to break out south of the warm
front this afternoon for us to destabilize. Given the general
guidance agreement, do have pretty high confidence this will occur
and we will become quite unstable across southern KY late this
afternoon.
The other potential bust factor will if discrete development will
occur late this afternoon/early evening. Warm fronts can be tricky
in initiating surface-based convection, so we could go through the
day not seeing much becoming sustained along the front. In
addition, the weak cap could hold through the rest of the warm
sector giving very little coverage of discrete convection until the
more concentrated line of storms approaches with the surface low
well after peak heating.
Summary
=======
While there is bust potential, have fairly high confidence in severe
weather this afternoon and evening. Think the main threats will be
hail and damaging winds, but an enhanced tornado threat will be
found right along the warm front. This is something we will
continue to monitor closely this afternoon. Even north of the warm
front in Lexington and Louisville, forecast soundings show quite a
bit of elevated instability above the stable boundary layer, so
severe hail will certainly be a possibility even in areas north of
the warm front.
.LONG TERM (Sunday through Friday)...
Issued at 230 AM EDT Sat Apr 25 2015
Cool and mostly dry conditions are expected from Sunday most of the
way through next week. Upper pattern looks fairly blocky as the main
player is an eastern CONUS trof that keeps getting reinforced.
Around mid-week a bowling-ball closed low in the southern stream
will push across the Deep South, with precip chances in the Ohio
Valley Wednesday and Wednesday night. Timing is still a bit
uncertain, and the ECMWF is more bullish in phasing this system with
a northern stream disturbance, so will just paint low-end chance
POPs for Wednesday and Wednesday night. Temps will run below climo
for most of this period.
Toward the end of the week, upper ridging over the Plains starts to
build into the Ohio Valley. Look for dry weather and exceedingly
pleasant temps with highs in the 70s and lows either side of 50 just
in time for the first weekend in May.
&&
.AVIATION (12Z TAF Update)...
Updated at 651 AM EDT Sat Apr 25 2015
Deteriorating conditions will push in through the TAF period, as an
area of low pressure approaches from the west. Showers will
continue to expand in coverage this morning, bringing MVFR vsbys at
cigs at times to all terminals. Will leave in VCTS wording given
some marginal elevated instability, but think any thunderstorm
activity will be rather isolated through the morning hours.
A warm front will sharpen and lift northeast into the area today.
Just north of this front, a period of IFR cigs can be expected at
all sites. The latest guidance suite continues to suggest this
front will likely stall just to the south of KSDF and KLEX, meaning
low cigs may persist in these locations through much of the day,
especially at KLEX. KBWG will likely scour out this afternoon and
mix down SSW wind gusts around 25 knots. Late this afternoon into
this evening, severe thunderstorms are expected to break out over
central KY, mainly affecting KBWG. However, there is enough
elevated instability to warrant VCTS wording at KSDF and KLEX as
well with this activity. Winds will turn more northerly late in the
TAF period as the area of low pressure pushes to the southeast.
12Z TAF Forecaster Confidence
=============================
Ceilings : Medium
Visibilities: Medium
Winds : Low at KSDF and KLEX
=============================
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........KJD
Short Term.....KJD
Long Term......RAS
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
623 AM EDT Sat Apr 25 2015
...Forecast Update...
Updated 621 AM EDT Sat Apr 25 2015
No major changes needed to the forecast this morning, as it is
largely on track. Still expecting rain showers to continue to
blossom over the region, especially along and north of I-64 this
morning. This is all in response to a low-level jet and isentropic
ascent veering into the region. May see a few rumbles of thunder
especially as we get into the late morning hours, but no severe
weather is expected through noon.
The 06Z NAM has come in further north with the warm frontal
placement late this afternoon, which would bring the I-64 corridor
more into play for severe potential. However, the latest runs of
the HRRR continue to show the warm front stalling south of I-64 and
very close to the current forecast position. Given the HRRR has a
decent handle on ongoing convection, and the support of the other
hi-res guidance in regards to expected frontal position this
afternoon, see no need to adjust things further north based on the
06Z NAM quite yet. Will continue to monitor trends through the
morning hours and especially the 12Z guidance suite.
.SHORT TERM (Now through Saturday Night)...
Issued at 345 AM EDT Sat Apr 25 2015
...Severe Weather Likely This Afternoon and Evening...
Overview
========
The current synoptic setup features a split-flow regime across the
CONUS. The Ohio Valley will be affected by a PV anomaly currently
across eastern Kansas and western MO, which will push through the
region late this afternoon into tonight.
In response to the ejecting PV anomaly out of the southwest flow
aloft, a surface low has formed across portions of eastern KS. This
low will slide east today, but will begin to fill as the overall
system encounters confluent flow over the Ohio Valley. A very sharp
warm front associated with this low pressure system will develop
across the Ohio Valley today.
This Morning
============
With the ejecting wave, isentropic ascent has increased across the
region this morning. This has led to showers breaking out across
the Ohio Valley, and the radar should continue to blossom through
the morning hours as a low-level jet of 40-50 knots veers into the
region towards sunrise. Forecast soundings show limited elevated
instability, so severe weather is not expected. Just some showers
with a few embedded rumbles of thunder appears likely.
This Afternoon/Evening
======================
The placement of the aforementioned sharp warm front will be
absolutely critical to how far north the severe weather threat gets
this afternoon/evening. The 25/00Z guidance shifted this front
south just a bit from previous runs, which would take much of the
I-64 corridor out of the main severe risk. Will cautiously trend
the forecast towards this more southern solution given the support
on almost guidance members, but still am a bit weary this front
could end up surging further north, especially if there is less
showers/storm coverage this morning than expected (less convective
enhancement to the front). This warm front will be the main player
that we will continue to monitor through the day.
At this point, expect the front to align itself roughly along a line
from Owensboro, to north of Elizabethtown, over towards Lebanon
by late this afternoon. To the south of it, a warm and unstable
airmass is likely to materialize given temperatures rising to near
80 and dewpoints in the middle 60s. This low-level environment
coupled with very steep lapse rates aloft will support MLCAPEs
anywhere from 1500-3000 J/kg, with much of that CAPE residing within
the hail growth zone (-10 to -30C).
The evolution of the convection could be rather complex. There
seems to be a decent signal in the hi-res guidance that the strong
warm front may lead to convective initiation, which will likely be
initially discrete in nature. Given 0-6km shear well over 50 knots,
these will be supercellular, if they are to form. The aforementioned
instability coupled with deep-layer shear will lead to a large hail
threat, with golf ball to even baseball-sized hail not out of the
question in some of these storms. Bunker`s RM storm motion vectors
place the motion of these potential supercells almost parallel to
the warm front, which is worrisome because any storm that forms
along this front will have access to enhanced helicity, given the
backed surface winds. Therefore, think there is an enhanced tornado
threat right along this boundary wherever it happens to set up,
perhaps more of a threat than SPC is currently highlighting with
their 5% Tornado risk.
Further south (across far southern KY, near TN border), strong
mixing coupled with the fact that the surface low will be filling
will lead to more veered surface winds, which should cut down
somewhere on the effective SRH. However, with westerly low-level
jet expected to strengthen towards 26/00Z, hodographs will be
long/curved enough to support an isolated tornado threat early this
evening in areas south of the warm front. Coverage of these storms
not tied to the warm front will likely be rather isolated, given a
lack of convergence and the presence of a weak cap in the warm
sector.
By a bit later this evening, the actual surface low will push into
west-central KY. Near the triple point of this low, enhanced
convergence will likely lead to a more concentrated area of
convection, perhaps a mix of bowing segments and supercells which
will push into the I-65 corridor toward 02-04Z. By this time,
daytime instability should be beginning to wane, but still think
this second round will carry a severe threat of large hail, damaging
winds, and isolated tornadoes as it pushes southeast across
south-central KY.
Bust Potential
==============
There remains some potential bust factors with this setup. The
first and most obvious, is the morning convection. We will need
this to clear out and some sunshine to break out south of the warm
front this afternoon for us to destabilize. Given the general
guidance agreement, do have pretty high confidence this will occur
and we will become quite unstable across southern KY late this
afternoon.
The other potential bust factor will if discrete development will
occur late this afternoon/early evening. Warm fronts can be tricky
in initiating surface-based convection, so we could go through the
day not seeing much becoming sustained along the front. In
addition, the weak cap could hold through the rest of the warm
sector giving very little coverage of discrete convection until the
more concentrated line of storms approaches with the surface low
well after peak heating.
Summary
=======
While there is bust potential, have fairly high confidence in severe
weather this afternoon and evening. Think the main threats will be
hail and damaging winds, but an enhanced tornado threat will be
found right along the warm front. This is something we will
continue to monitor closely this afternoon. Even north of the warm
front in Lexington and Louisville, forecast soundings show quite a
bit of elevated instability above the stable boundary layer, so
severe hail will certainly be a possibility even in areas north of
the warm front.
.LONG TERM (Sunday through Friday)...
Issued at 230 AM EDT Sat Apr 25 2015
Cool and mostly dry conditions are expected from Sunday most of the
way through next week. Upper pattern looks fairly blocky as the main
player is an eastern CONUS trof that keeps getting reinforced.
Around mid-week a bowling-ball closed low in the southern stream
will push across the Deep South, with precip chances in the Ohio
Valley Wednesday and Wednesday night. Timing is still a bit
uncertain, and the ECMWF is more bullish in phasing this system with
a northern stream disturbance, so will just paint low-end chance
POPs for Wednesday and Wednesday night. Temps will run below climo
for most of this period.
Toward the end of the week, upper ridging over the Plains starts to
build into the Ohio Valley. Look for dry weather and exceedingly
pleasant temps with highs in the 70s and lows either side of 50 just
in time for the first weekend in May.
&&
.AVIATION (06Z TAF Update)...
Updated at 118 AM EDT Sat Apr 25 2015
Deteriorating conditions will push in through the TAF period, as an
area of low pressure approaches from the west. Showers will
continue to expand in coverage early this morning, bringing MVFR
vsbys at cigs at times to all terminals. Will leave in VCTS wording
given some marginal elevated instability, but think any thunderstorm
activity will be rather isolated. Winds will be out of east at 5-10
knots through the remainder of the overnight period.
A warm front, now located over MO/AR will lift northeast through the
morning hours. Just north of this front, a period of IFR cigs can
be expected at all sites. In fact, the latest guidance suite
suggests this front will likely stall to the south of KSDF and KLEX,
meaning low cigs may persist in these locations through much of the
day. Will trend the forecast toward the pessimistic side to account
for this trend. KBWG will likely scour out this afternoon and mix
down SSW wind gusts around 25 knots. Late this afternoon into this
evening, severe thunderstorms are expected to break out over central
KY, mainly affecting KBWG. However, there is enough elevated
instability to warrant VCTS wording at KSDF and KLEX as well with
this activity. Winds will turn more northerly late in the TAF
period as the area of low pressure pushes to the southeast.
06Z TAF Forecaster Confidence
=============================
Ceilings : Medium
Visibilities: Medium
Winds : Medium
=============================
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........KJD
Short Term.....KJD
Long Term......RAS
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
908 AM CDT SAT APR 25 2015
.UPDATE...
BASED ON DISCUSSION WITH SPC...DECIDED TO EXPAND THE SEVERE
THUNDERSTORM WATCH IN AREA.
&&
.PREV DISCUSSION... /ISSUED 729 AM CDT SAT APR 25 2015/
UPDATE...
UPDATED PRODUCTS TO INCLUDE SVR TSTM WATCH 109 WHICH IS IN EFFECT
THROUGH 1 PM. BAND OF STRONG TO SVR STORMS CONTINUES TO MARCH EAST
ACRS SE TX AND THE STRONGEST STORMS SHOULD BE ENTERING WRN
JEFFERSON COUNTY WITHIN THE HOUR. 24
PREV DISCUSSION... /ISSUED 659 AM CDT SAT APR 25 2015/
DISCUSSION...
FOR THE 12Z TAF PACKAGE.
AVIATION...
MIX OF GENERALLY MVFR CIGS AND/OR VSBYS THIS MORNING...WITH
REGIONAL RADAR IMAGERY SHOWING AN INCREASE IN UPSTREAM CONVECTIVE
ACTIVITY OVER EAST TEXAS. LATEST SHORT RANGE GUIDANCE SUGGESTS AN
EASTWARD EXPANSION/MOVEMENT THROUGH THE MORNING HOURS. WHILE THERE
WILL LIKELY BE EMBEDDED THUNDERSTORMS...SHOWER ACTIVITY SHOULD
PREVAIL. INSERTED A TEMPO FOR SHOWERS AT EACH TERMINAL BASED ON
LATEST RADAR TRENDS AND SHORT TERM GUIDANCE. CLOUD COVER MAY
SCATTER OUT/LIFT MORE THAN CURRENTLY FCST FOR THE AFTERNOON HRS AS
DRIER AIR ALOFT WORKS IN FROM THE WEST...BUT MSTR IS PROGGED TO
REMAIN TRAPPED NEAR THE SFC...LEADING TO ANOTHER ROUND OF LOWER
CIGS/VSBYS TONIGHT INTO EARLY SUN.
13
PREV DISCUSSION... /ISSUED 547 AM CDT SAT APR 25 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WATER VAPOR IMAGERY SHOWS AN UPR LOW OVER
KS...WITH A SHORTWAVE TROF EXTENDING SOUTH ACRS OK AND TX. AMPLE
MOISTURE CONTINUES TO STREAM ACRS THE REGION ON SWLY FLOW ALOFT.
LATEST RADAR MOSAIC SHOWS TWO MAIN CLUSTERS OF CONVECTION...A
COUPLE OF BANDS OF SHOWERS AND TSTMS EXITING THE LOWER MS VALLEY
AND ANOTHER AREA OF STORMS UPSTREAM ACRS THE HILL COUNTRY IN TX.
THIS IS THE NEXT SYSTEM TO MOVE INTO THE AREA...AND WILL BEAR
WATCHING THROUGH THE MORNING AND EARLY AFTN.
DISCUSSION...
LATEST HRRR RUNS SHOW THE CLUSTER OF STORMS ACRS TX MOVING INTO
OUR AREA LIKELY AROUND 9 OR 10 AM THIS MORNING. THIS ACTIVITY WILL
CROSS THE AREA EARLY TODAY...WITH MOST OF THE CONVECTION EXPECTED
TO BE CONCENTRATED ACRS SRN PORTIONS OF THE AREA. IT IS FCST TO
EVENTUALLY EXIT THE OUR S CNTL LA ZONES BETWEEN 1 AND 3 PM. PLENTY
OF MOISTURE IS AVAILABLE WITH PW VALUES RUNNING CLOSE TO 1.8
INCHES...AND LIFT WILL BE HELPED BY THE PRESENCE OF A ROBUST RIGHT
ENTRANCE REGION BENEATH THE UPPER JET. AS A RESULT...SOME STORMS
WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL ALONG WITH A
FEW STRONG STORMS AMIDST MODT LOW LVL SHEAR.
RAIN CHCS WILL GRADUALLY DIMINISH THROUGH THE AFTN AS THE MAIN
ENERGY WITH THE DISTURBANCE MOVES OFF TO THE EAST. A BRIEF BREAK
FROM THE SHOWERS AND TSTMS ARRIVES TONIGHT INTO SUNDAY AS SLIGHTLY
DRIER AIR ALOFT MOVES INTO THE REGION. HOWEVER...THE NEXT
DISTURBANCE UPSTREAM WILL BEGIN TAKING SHAPE AS AN UPR LOW DIVES
SE ACRS THE INTERMOUNTAIN WEST SUNDAY. THIS LOW WILL EJECT INTO
THE SRN PLAINS MONDAY...WITH A MOIST AND DIVERGENT SWLY FLOW
BECOMING RE-ESTABLISHED OVER THE AREA. SFC CYCLOGENESIS WILL ALSO
DEVELOP OVER TX ON MONDAY...WITH A MIDLVL JET TRANSLATING EAST
TOWARD ERN TX. EXPECT SHOWERS AND TSTMS TO DEVELOP OVER TX SUNDAY
NIGHT...THEN SPREAD EAST ACRS THE AREA MONDAY. INSTABILITY WILL
INCREASE ON MONDAY WITH WIND PROFILES SHOWING STRONG VEERING WITH
HEIGHT AND HELICITY VALUES EXCEEDING 200 M2/S2. SPC HAS THE
REGION HIGHLIGHTED IN A SLT RISK FOR SVR STORMS WITH LARGE
HAIL...STRONG WINDS AND EVEN A FEW TORNADOES POSSIBLE. IN
ADDITION...STORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS. LIKELY POPS REMAIN OVER THE AREA MONDAY NIGHT...THEN
GRADUALLY DIMINISH FROM WEST TO EAST TUESDAY AS THE SYSTEM SHIFTS
EAST OVER THE LOWER MS VALLEY.
MEANWHILE...THE SFC LOW OVER TX WILL MOVE EAST NR THE COAST MONDAY
NIGHT INTO TUESDAY. NLY FLOW WILL DEVELOP BEHIND THE SFC
LOW...WITH DRIER NWLY FLOW DEVELOPING ALOFT. THIS WILL FINALLY
BRING AN END TO THE RAIN...WITH DRIER...COOLER AND MORE
COMFORTABLE CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE WEEK.
OVERNIGHT LOWS WEDNESDAY AND THURSDAY MORNING ARE EXPECTED TO FALL
INTO THE 50S...COOLER THAN NORMAL FOR THIS TIME OF YEAR...WHILE
HIGHS WILL BE IN THE 70S. THE DRY WEATHER WILL CONTINUE INTO THE
WEEKEND WITH A GRADUAL WARMING TREND DEVELOPING.
24
MARINE...
A MDT SLY FLOW WILL CONTINUE THROUGH MONDAY WITH HIGH PRES
EAST OF THE REGION AND A SERIES OF LOW PRES SYSTEMS DEVELOPING WEST
OF THE AREA. AN UPR LVL DISTURBANCE MOVING THROUGH THE REGION WILL
KEEP A CHC FOR SHOWERS AND STORMS TODAY. ANOTHER DISTURBANCE WILL
MOVE INTO THE AREA ON MONDAY...BRINGING ANOTHER CHC FOR SHOWERS
AND TSTMS. AS THIS DISTURBANCE CROSSES THE AREA...IT WILL INDUCE
SFC LOW PRES OVER TX. THIS LOW WILL THEN CROSS THE COASTAL WATERS
MONDAY NIGHT...WITH A TRAILING COLD FRONT MOVING THROUGH ON
TUESDAY. SOME OF THE STORMS WITH THIS SYSTEM COULD BE
STRONG...CAPABLE OF PRODUCING GUSTY WINDS AND FREQUENT CLOUD TO
WATER LIGHTNING. ONCE THE FRONT PASSES THROUGH THE AREA...RAIN
CHCS WILL COME TO AN END...WITH MODT TO STRONG NLY WINDS
DEVELOPING POSSIBLY BRINGING SMALL CRAFT ADVISORY CONDITIONS TO
THE WATERS TUESDAY NIGHT INTO WEDNESDAY.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 87 67 89 66 / 40 10 20 20
LCH 82 70 85 70 / 50 10 20 20
LFT 85 69 88 69 / 50 10 20 20
BPT 84 69 85 70 / 50 10 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...27
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
729 AM CDT SAT APR 25 2015
.UPDATE...
UPDATED PRODUCTS TO INCLUDE SVR TSTM WATCH 109 WHICH IS IN EFFECT
THROUGH 1 PM. BAND OF STRONG TO SVR STORMS CONTINUES TO MARCH EAST
ACRS SE TX AND THE STRONGEST STORMS SHOULD BE ENTERING WRN
JEFFERSON COUNTY WITHIN THE HOUR. 24
&&
.PREV DISCUSSION... /ISSUED 659 AM CDT SAT APR 25 2015/
DISCUSSION...
FOR THE 12Z TAF PACKAGE.
AVIATION...
MIX OF GENERALLY MVFR CIGS AND/OR VSBYS THIS MORNING...WITH
REGIONAL RADAR IMAGERY SHOWING AN INCREASE IN UPSTREAM CONVECTIVE
ACTIVITY OVER EAST TEXAS. LATEST SHORT RANGE GUIDANCE SUGGESTS AN
EASTWARD EXPANSION/MOVEMENT THROUGH THE MORNING HOURS. WHILE THERE
WILL LIKELY BE EMBEDDED THUNDERSTORMS...SHOWER ACTIVITY SHOULD
PREVAIL. INSERTED A TEMPO FOR SHOWERS AT EACH TERMINAL BASED ON
LATEST RADAR TRENDS AND SHORT TERM GUIDANCE. CLOUD COVER MAY
SCATTER OUT/LIFT MORE THAN CURRENTLY FCST FOR THE AFTERNOON HRS AS
DRIER AIR ALOFT WORKS IN FROM THE WEST...BUT MSTR IS PROGGED TO
REMAIN TRAPPED NEAR THE SFC...LEADING TO ANOTHER ROUND OF LOWER
CIGS/VSBYS TONIGHT INTO EARLY SUN.
13
PREV DISCUSSION... /ISSUED 547 AM CDT SAT APR 25 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WATER VAPOR IMAGERY SHOWS AN UPR LOW OVER
KS...WITH A SHORTWAVE TROF EXTENDING SOUTH ACRS OK AND TX. AMPLE
MOISTURE CONTINUES TO STREAM ACRS THE REGION ON SWLY FLOW ALOFT.
LATEST RADAR MOSAIC SHOWS TWO MAIN CLUSTERS OF CONVECTION...A
COUPLE OF BANDS OF SHOWERS AND TSTMS EXITING THE LOWER MS VALLEY
AND ANOTHER AREA OF STORMS UPSTREAM ACRS THE HILL COUNTRY IN TX.
THIS IS THE NEXT SYSTEM TO MOVE INTO THE AREA...AND WILL BEAR
WATCHING THROUGH THE MORNING AND EARLY AFTN.
DISCUSSION...
LATEST HRRR RUNS SHOW THE CLUSTER OF STORMS ACRS TX MOVING INTO
OUR AREA LIKELY AROUND 9 OR 10 AM THIS MORNING. THIS ACTIVITY WILL
CROSS THE AREA EARLY TODAY...WITH MOST OF THE CONVECTION EXPECTED
TO BE CONCENTRATED ACRS SRN PORTIONS OF THE AREA. IT IS FCST TO
EVENTUALLY EXIT THE OUR S CNTL LA ZONES BETWEEN 1 AND 3 PM. PLENTY
OF MOISTURE IS AVAILABLE WITH PW VALUES RUNNING CLOSE TO 1.8
INCHES...AND LIFT WILL BE HELPED BY THE PRESENCE OF A ROBUST RIGHT
ENTRANCE REGION BENEATH THE UPPER JET. AS A RESULT...SOME STORMS
WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL ALONG WITH A
FEW STRONG STORMS AMIDST MODT LOW LVL SHEAR.
RAIN CHCS WILL GRADUALLY DIMINISH THROUGH THE AFTN AS THE MAIN
ENERGY WITH THE DISTURBANCE MOVES OFF TO THE EAST. A BRIEF BREAK
FROM THE SHOWERS AND TSTMS ARRIVES TONIGHT INTO SUNDAY AS SLIGHTLY
DRIER AIR ALOFT MOVES INTO THE REGION. HOWEVER...THE NEXT
DISTURBANCE UPSTREAM WILL BEGIN TAKING SHAPE AS AN UPR LOW DIVES
SE ACRS THE INTERMOUNTAIN WEST SUNDAY. THIS LOW WILL EJECT INTO
THE SRN PLAINS MONDAY...WITH A MOIST AND DIVERGENT SWLY FLOW
BECOMING RE-ESTABLISHED OVER THE AREA. SFC CYCLOGENESIS WILL ALSO
DEVELOP OVER TX ON MONDAY...WITH A MIDLVL JET TRANSLATING EAST
TOWARD ERN TX. EXPECT SHOWERS AND TSTMS TO DEVELOP OVER TX SUNDAY
NIGHT...THEN SPREAD EAST ACRS THE AREA MONDAY. INSTABILITY WILL
INCREASE ON MONDAY WITH WIND PROFILES SHOWING STRONG VEERING WITH
HEIGHT AND HELICITY VALUES EXCEEDING 200 M2/S2. SPC HAS THE
REGION HIGHLIGHTED IN A SLT RISK FOR SVR STORMS WITH LARGE
HAIL...STRONG WINDS AND EVEN A FEW TORNADOES POSSIBLE. IN
ADDITION...STORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS. LIKELY POPS REMAIN OVER THE AREA MONDAY NIGHT...THEN
GRADUALLY DIMINISH FROM WEST TO EAST TUESDAY AS THE SYSTEM SHIFTS
EAST OVER THE LOWER MS VALLEY.
MEANWHILE...THE SFC LOW OVER TX WILL MOVE EAST NR THE COAST MONDAY
NIGHT INTO TUESDAY. NLY FLOW WILL DEVELOP BEHIND THE SFC
LOW...WITH DRIER NWLY FLOW DEVELOPING ALOFT. THIS WILL FINALLY
BRING AN END TO THE RAIN...WITH DRIER...COOLER AND MORE
COMFORTABLE CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE WEEK.
OVERNIGHT LOWS WEDNESDAY AND THURSDAY MORNING ARE EXPECTED TO FALL
INTO THE 50S...COOLER THAN NORMAL FOR THIS TIME OF YEAR...WHILE
HIGHS WILL BE IN THE 70S. THE DRY WEATHER WILL CONTINUE INTO THE
WEEKEND WITH A GRADUAL WARMING TREND DEVELOPING.
24
MARINE...
A MDT SLY FLOW WILL CONTINUE THROUGH MONDAY WITH HIGH PRES
EAST OF THE REGION AND A SERIES OF LOW PRES SYSTEMS DEVELOPING WEST
OF THE AREA. AN UPR LVL DISTURBANCE MOVING THROUGH THE REGION WILL
KEEP A CHC FOR SHOWERS AND STORMS TODAY. ANOTHER DISTURBANCE WILL
MOVE INTO THE AREA ON MONDAY...BRINGING ANOTHER CHC FOR SHOWERS
AND TSTMS. AS THIS DISTURBANCE CROSSES THE AREA...IT WILL INDUCE
SFC LOW PRES OVER TX. THIS LOW WILL THEN CROSS THE COASTAL WATERS
MONDAY NIGHT...WITH A TRAILING COLD FRONT MOVING THROUGH ON
TUESDAY. SOME OF THE STORMS WITH THIS SYSTEM COULD BE
STRONG...CAPABLE OF PRODUCING GUSTY WINDS AND FREQUENT CLOUD TO
WATER LIGHTNING. ONCE THE FRONT PASSES THROUGH THE AREA...RAIN
CHCS WILL COME TO AN END...WITH MODT TO STRONG NLY WINDS
DEVELOPING POSSIBLY BRINGING SMALL CRAFT ADVISORY CONDITIONS TO
THE WATERS TUESDAY NIGHT INTO WEDNESDAY.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 87 67 89 66 / 40 10 20 20
LCH 82 70 85 70 / 50 10 20 20
LFT 85 69 88 69 / 50 10 20 20
BPT 84 69 85 70 / 50 10 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
659 AM CDT SAT APR 25 2015
.DISCUSSION...
FOR THE 12Z TAF PACKAGE.
&&
.AVIATION...
MIX OF GENERALLY MVFR CIGS AND/OR VSBYS THIS MORNING...WITH
REGIONAL RADAR IMAGERY SHOWING AN INCREASE IN UPSTREAM CONVECTIVE
ACTIVITY OVER EAST TEXAS. LATEST SHORT RANGE GUIDANCE SUGGESTS AN
EASTWARD EXPANSION/MOVEMENT THROUGH THE MORNING HOURS. WHILE THERE
WILL LIKELY BE EMBEDDED THUNDERSTORMS...SHOWER ACTIVITY SHOULD
PREVAIL. INSERTED A TEMPO FOR SHOWERS AT EACH TERMINAL BASED ON
LATEST RADAR TRENDS AND SHORT TERM GUIDANCE. CLOUD COVER MAY
SCATTER OUT/LIFT MORE THAN CURRENTLY FCST FOR THE AFTERNOON HRS AS
DRIER AIR ALOFT WORKS IN FROM THE WEST...BUT MSTR IS PROGGED TO
REMAIN TRAPPED NEAR THE SFC...LEADING TO ANOTHER ROUND OF LOWER
CIGS/VSBYS TONIGHT INTO EARLY SUN.
13
&&
.PREV DISCUSSION... /ISSUED 547 AM CDT SAT APR 25 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WATER VAPOR IMAGERY SHOWS AN UPR LOW OVER
KS...WITH A SHORTWAVE TROF EXTENDING SOUTH ACRS OK AND TX. AMPLE
MOISTURE CONTINUES TO STREAM ACRS THE REGION ON SWLY FLOW ALOFT.
LATEST RADAR MOSAIC SHOWS TWO MAIN CLUSTERS OF CONVECTION...A
COUPLE OF BANDS OF SHOWERS AND TSTMS EXITING THE LOWER MS VALLEY
AND ANOTHER AREA OF STORMS UPSTREAM ACRS THE HILL COUNTRY IN TX.
THIS IS THE NEXT SYSTEM TO MOVE INTO THE AREA...AND WILL BEAR
WATCHING THROUGH THE MORNING AND EARLY AFTN.
DISCUSSION...
LATEST HRRR RUNS SHOW THE CLUSTER OF STORMS ACRS TX MOVING INTO
OUR AREA LIKELY AROUND 9 OR 10 AM THIS MORNING. THIS ACTIVITY WILL
CROSS THE AREA EARLY TODAY...WITH MOST OF THE CONVECTION EXPECTED
TO BE CONCENTRATED ACRS SRN PORTIONS OF THE AREA. IT IS FCST TO
EVENTUALLY EXIT THE OUR S CNTL LA ZONES BETWEEN 1 AND 3 PM. PLENTY
OF MOISTURE IS AVAILABLE WITH PW VALUES RUNNING CLOSE TO 1.8
INCHES...AND LIFT WILL BE HELPED BY THE PRESENCE OF A ROBUST RIGHT
ENTRANCE REGION BENEATH THE UPPER JET. AS A RESULT...SOME STORMS
WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL ALONG WITH A
FEW STRONG STORMS AMIDST MODT LOW LVL SHEAR.
RAIN CHCS WILL GRADUALLY DIMINISH THROUGH THE AFTN AS THE MAIN
ENERGY WITH THE DISTURBANCE MOVES OFF TO THE EAST. A BRIEF BREAK
FROM THE SHOWERS AND TSTMS ARRIVES TONIGHT INTO SUNDAY AS SLIGHTLY
DRIER AIR ALOFT MOVES INTO THE REGION. HOWEVER...THE NEXT
DISTURBANCE UPSTREAM WILL BEGIN TAKING SHAPE AS AN UPR LOW DIVES
SE ACRS THE INTERMOUNTAIN WEST SUNDAY. THIS LOW WILL EJECT INTO
THE SRN PLAINS MONDAY...WITH A MOIST AND DIVERGENT SWLY FLOW
BECOMING RE-ESTABLISHED OVER THE AREA. SFC CYCLOGENESIS WILL ALSO
DEVELOP OVER TX ON MONDAY...WITH A MIDLVL JET TRANSLATING EAST
TOWARD ERN TX. EXPECT SHOWERS AND TSTMS TO DEVELOP OVER TX SUNDAY
NIGHT...THEN SPREAD EAST ACRS THE AREA MONDAY. INSTABILITY WILL
INCREASE ON MONDAY WITH WIND PROFILES SHOWING STRONG VEERING WITH
HEIGHT AND HELICITY VALUES EXCEEDING 200 M2/S2. SPC HAS THE
REGION HIGHLIGHTED IN A SLT RISK FOR SVR STORMS WITH LARGE
HAIL...STRONG WINDS AND EVEN A FEW TORNADOES POSSIBLE. IN
ADDITION...STORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS. LIKELY POPS REMAIN OVER THE AREA MONDAY NIGHT...THEN
GRADUALLY DIMINISH FROM WEST TO EAST TUESDAY AS THE SYSTEM SHIFTS
EAST OVER THE LOWER MS VALLEY.
MEANWHILE...THE SFC LOW OVER TX WILL MOVE EAST NR THE COAST MONDAY
NIGHT INTO TUESDAY. NLY FLOW WILL DEVELOP BEHIND THE SFC
LOW...WITH DRIER NWLY FLOW DEVELOPING ALOFT. THIS WILL FINALLY
BRING AN END TO THE RAIN...WITH DRIER...COOLER AND MORE
COMFORTABLE CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE WEEK.
OVERNIGHT LOWS WEDNESDAY AND THURSDAY MORNING ARE EXPECTED TO FALL
INTO THE 50S...COOLER THAN NORMAL FOR THIS TIME OF YEAR...WHILE
HIGHS WILL BE IN THE 70S. THE DRY WEATHER WILL CONTINUE INTO THE
WEEKEND WITH A GRADUAL WARMING TREND DEVELOPING.
24
MARINE...
A MDT SLY FLOW WILL CONTINUE THROUGH MONDAY WITH HIGH PRES
EAST OF THE REGION AND A SERIES OF LOW PRES SYSTEMS DEVELOPING WEST
OF THE AREA. AN UPR LVL DISTURBANCE MOVING THROUGH THE REGION WILL
KEEP A CHC FOR SHOWERS AND STORMS TODAY. ANOTHER DISTURBANCE WILL
MOVE INTO THE AREA ON MONDAY...BRINGING ANOTHER CHC FOR SHOWERS
AND TSTMS. AS THIS DISTURBANCE CROSSES THE AREA...IT WILL INDUCE
SFC LOW PRES OVER TX. THIS LOW WILL THEN CROSS THE COASTAL WATERS
MONDAY NIGHT...WITH A TRAILING COLD FRONT MOVING THROUGH ON
TUESDAY. SOME OF THE STORMS WITH THIS SYSTEM COULD BE
STRONG...CAPABLE OF PRODUCING GUSTY WINDS AND FREQUENT CLOUD TO
WATER LIGHTNING. ONCE THE FRONT PASSES THROUGH THE AREA...RAIN
CHCS WILL COME TO AN END...WITH MODT TO STRONG NLY WINDS
DEVELOPING POSSIBLY BRINGING SMALL CRAFT ADVISORY CONDITIONS TO
THE WATERS TUESDAY NIGHT INTO WEDNESDAY.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 87 67 89 66 / 40 10 20 20
LCH 82 70 85 70 / 50 10 20 20
LFT 85 69 88 69 / 50 10 20 20
BPT 84 69 85 70 / 50 10 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE...24
AVIATION...13
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
547 AM CDT SAT APR 25 2015
.SYNOPSIS...
LATEST UA ANALYSIS AND WATER VAPOR IMAGERY SHOWS AN UPR LOW OVER
KS...WITH A SHORTWAVE TROF EXTENDING SOUTH ACRS OK AND TX. AMPLE
MOISTURE CONTINUES TO STREAM ACRS THE REGION ON SWLY FLOW ALOFT.
LATEST RADAR MOSAIC SHOWS TWO MAIN CLUSTERS OF CONVECTION...A
COUPLE OF BANDS OF SHOWERS AND TSTMS EXITING THE LOWER MS VALLEY
AND ANOTHER AREA OF STORMS UPSTREAM ACRS THE HILL COUNTRY IN TX.
THIS IS THE NEXT SYSTEM TO MOVE INTO THE AREA...AND WILL BEAR
WATCHING THROUGH THE MORNING AND EARLY AFTN.
&&
.DISCUSSION...
LATEST HRRR RUNS SHOW THE CLUSTER OF STORMS ACRS TX MOVING INTO
OUR AREA LIKELY AROUND 9 OR 10 AM THIS MORNING. THIS ACTIVITY WILL
CROSS THE AREA EARLY TODAY...WITH MOST OF THE CONVECTION EXPECTED
TO BE CONCENTRATED ACRS SRN PORTIONS OF THE AREA. IT IS FCST TO
EVENTUALLY EXIT THE OUR S CNTL LA ZONES BETWEEN 1 AND 3 PM. PLENTY
OF MOISTURE IS AVAILABLE WITH PW VALUES RUNNING CLOSE TO 1.8
INCHES...AND LIFT WILL BE HELPED BY THE PRESENCE OF A ROBUST RIGHT
ENTRANCE REGION BENEATH THE UPPER JET. AS A RESULT...SOME STORMS
WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL ALONG WITH A
FEW STRONG STORMS AMIDST MODT LOW LVL SHEAR.
RAIN CHCS WILL GRADUALLY DIMINISH THROUGH THE AFTN AS THE MAIN
ENERGY WITH THE DISTURBANCE MOVES OFF TO THE EAST. A BRIEF BREAK
FROM THE SHOWERS AND TSTMS ARRIVES TONIGHT INTO SUNDAY AS SLIGHTLY
DRIER AIR ALOFT MOVES INTO THE REGION. HOWEVER...THE NEXT
DISTURBANCE UPSTREAM WILL BEGIN TAKING SHAPE AS AN UPR LOW DIVES
SE ACRS THE INTERMOUNTAIN WEST SUNDAY. THIS LOW WILL EJECT INTO
THE SRN PLAINS MONDAY...WITH A MOIST AND DIVERGENT SWLY FLOW
BECOMING RE-ESTABLISHED OVER THE AREA. SFC CYCLOGENESIS WILL ALSO
DEVELOP OVER TX ON MONDAY...WITH A MIDLVL JET TRANSLATING EAST
TOWARD ERN TX. EXPECT SHOWERS AND TSTMS TO DEVELOP OVER TX SUNDAY
NIGHT...THEN SPREAD EAST ACRS THE AREA MONDAY. INSTABILITY WILL
INCREASE ON MONDAY WITH WIND PROFILES SHOWING STRONG VEERING WITH
HEIGHT AND HELICITY VALUES EXCEEDING 200 M2/S2. SPC HAS THE
REGION HIGHLIGHTED IN A SLT RISK FOR SVR STORMS WITH LARGE
HAIL...STRONG WINDS AND EVEN A FEW TORNADOES POSSIBLE. IN
ADDITION...STORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS. LIKELY POPS REMAIN OVER THE AREA MONDAY NIGHT...THEN
GRADUALLY DIMINISH FROM WEST TO EAST TUESDAY AS THE SYSTEM SHIFTS
EAST OVER THE LOWER MS VALLEY.
MEANWHILE...THE SFC LOW OVER TX WILL MOVE EAST NR THE COAST MONDAY
NIGHT INTO TUESDAY. NLY FLOW WILL DEVELOP BEHIND THE SFC
LOW...WITH DRIER NWLY FLOW DEVELOPING ALOFT. THIS WILL FINALLY
BRING AN END TO THE RAIN...WITH DRIER...COOLER AND MORE
COMFORTABLE CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE WEEK.
OVERNIGHT LOWS WEDNESDAY AND THURSDAY MORNING ARE EXPECTED TO FALL
INTO THE 50S...COOLER THAN NORMAL FOR THIS TIME OF YEAR...WHILE
HIGHS WILL BE IN THE 70S. THE DRY WEATHER WILL CONTINUE INTO THE
WEEKEND WITH A GRADUAL WARMING TREND DEVELOPING.
&&
.MARINE...
A MDT SLY FLOW WILL CONTINUE THROUGH MONDAY WITH HIGH PRES
EAST OF THE REGION AND A SERIES OF LOW PRES SYSTEMS DEVELOPING WEST
OF THE AREA. AN UPR LVL DISTURBANCE MOVING THROUGH THE REGION WILL
KEEP A CHC FOR SHOWERS AND STORMS TODAY. ANOTHER DISTURBANCE WILL
MOVE INTO THE AREA ON MONDAY...BRINGING ANOTHER CHC FOR SHOWERS
AND TSTMS. AS THIS DISTURBANCE CROSSES THE AREA...IT WILL INDUCE
SFC LOW PRES OVER TX. THIS LOW WILL THEN CROSS THE COASTAL WATERS
MONDAY NIGHT...WITH A TRAILING COLD FRONT MOVING THROUGH ON
TUESDAY. SOME OF THE STORMS WITH THIS SYSTEM COULD BE
STRONG...CAPABLE OF PRODUCING GUSTY WINDS AND FREQUENT CLOUD TO
WATER LIGHTNING. ONCE THE FRONT PASSES THROUGH THE AREA...RAIN
CHCS WILL COME TO AN END...WITH MODT TO STRONG NLY WINDS
DEVELOPING POSSIBLY BRINGING SMALL CRAFT ADVISORY CONDITIONS TO
THE WATERS TUESDAY NIGHT INTO WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 87 67 89 66 / 40 10 20 20
LCH 82 70 85 70 / 50 10 20 20
LFT 85 69 88 69 / 50 10 20 20
BPT 84 69 85 70 / 50 10 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...04
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1157 AM EDT SAT APR 25 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 328 AM EDT SAT APR 25 2015
LIGHT RAIN SCATTERED AROUND THE AREA EARLY THIS MORNING WILL
DIMINISH AND MOVE SOUTH OF THE AREA DURING THE DAY TODAY. SKIES WILL
THEN CLEAR OUT FROM NORTH TO SOUTH LATER IN THE DAY. HIGH PRESSURE
WILL THEN BUILD IN ACROSS THE AREA FOR THE DAY ON SUNDAY...BRINGING
A COOL AND NICE DAY TO THE AREA.
THE FIRST PORTION OF THE UPCOMING WEEK LOOKS TO BE MAINLY DRY. SOME
CLOUDS MAY ROTATE IN FROM THE NE ON MONDAY AS A WAVE OF LOW PRESSURE
MOVES BY JUST EAST OF THE STATE. THE NEXT CHANCE OF RAIN WILL THEN
COME ON WEDNESDAY. TEMPERATURES WILL GRADUALLY MODERATE TO NEAR
AVERAGE...AND POTENTIALLY ABOVE AVERAGE LATE NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1145 AM EDT SAT APR 25 2015
WILL KEEP THE CHANCE OF LIGHT RAIN THIS AFTERNOON LIMITED TO AREAS
SOUTH OF A LINE FROM ROUGHLY HOLLAND TO JACKSON. LATEST SHORT
RANGE GUIDANCE SUCH AS THE HRRR AND RADAR TRENDS SUPPORT THIS
IDEA.
THE CLOUD FCST IS A BIT TRICKY NORTH OF I-96 AS LATEST VISIBLE
IMAGE SHOWS SOME THINNING TAKING PLACE IN THE MID CLOUD DECK. WILL
HAVE SKIES BECOMING PTLY TO MSTLY SUNNY UP NORTH BUT REMAINING
MOSTLY CLOUDY NEAR AND SOUTH OF I-96. WARMEST HIGH TEMPS THIS
AFTERNOON SHOULD WEST OF HIGHWAY 131 AND NORTH OF I-96 WHERE
READINGS MAY APPROACH LATER TODAY 60 DEPENDING ON AMOUNT OF
CLEARING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EDT SAT APR 25 2015
THE ONLY REAL CHALLENGE IN THE SHORT TERM IS DEALING WITH THE RAIN
CHCS DURING THE DAY TODAY WITH THE UPPER SYSTEM TRYING TO MOVE INTO
THE AREA.
THE TREND IN THE LATEST DATA ALL POINTS TOWARD ALMOST ALL
OF THE RAIN MISSING THE CWFA AFTER THE LINGERING LIGHT RAIN EARLY
THIS MORNING. THE UPPER TROUGH DROPPING INTO THE AREA ON THE WRN
FLANK OF THE UPPER LOW NEAR MAINE HAS TRENDED QUICKER/STRONGER AND
IS DEFLECTING THE PLAINS LOW FURTHER SOUTH. LATEST SATELLITE IMAGERY
APPEARS TO SUPPORT THE LIMIT IN NORTHWARD PROGRESS OF THE LOW IN THE
PLAINS. WE HAVE LEFT A SLIGHT CHC OF RAIN FOR THE DAYLIGHT HOURS
ALONG/SOUTH OF I-94.
ONCE THE TROUGH MOVES THROUGH THIS AFTERNOON...SKIES WILL CLEAR OUT
FROM NORTH TO SOUTH ACROSS THE AREA. WE WILL SEE A QUIET AND DRY
PERIOD SETTLE IN FOR TONIGHT THROUGH SUN NIGHT. THIS WILL BRING A
MILDER DAY ON SUN WITH A DECENT AMOUNT OF SUNSHINE. WE COULD BE
LOOKING AT A COUPLE OF NIGHTS/MORNINGS WITH SOME FROST AND POSSIBLE
HEADLINES FOR LOCATIONS IN THE GROWING SEASON ALREADY AS TEMPS WILL
BE DROPPING INTO THE MID 30S. ENOUGH WIND MAY REMAIN UP SUN NIGHT TO
PREVENT FROST DEVELOPMENT.
WE ARE WATCHING FOR THE POTENTIAL TO POSSIBLY NEED TO ADD SOME LOW
CHCS OF PCPN IN FOR THE DAY ON MON. ANOTHER TROUGH WILL ROTATE SOUTH
THROUGH THE ERN PORTION OF THE STATE ON MON. SOME MOISTURE WILL
ADVECT IN ALSO WITH THE TROUGH. MOISTURE WILL BE RATHER SHALLOW IN
NATURE...SO WE ARE THINKING THAT AN INCREASE IN CLOUD COVER RIGHT
NOW FOR THE ERN SECTION OF THE CWFA IS APPROPRIATE AT THIS TIME.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT APR 25 2015
THE LONG TERM PERIOD LOOKS TO BE QUITE UNEVENTFUL WITH MODERATING
TEMPERATURES AND VERY LITTLE PRECIPITATION. THE UPPER PATTERN WILL
GRADUALLY TREND TOWARDS HIGHER HEIGHTS AND EVEN RIDGING BY NEXT
WEEKEND. 850MB TEMPERATURES WARM FROM AROUND ZERO C MONDAY
NIGHT...TO NEAR +10 C NEXT FRI/SAT. HIGH TEMPERATURES SHOULD WARM
FROM AROUND 60 ON TUESDAY TO AROUND 70 BY NEXT SATURDAY. NEXT
SUNDAY/S HIGHS COULD BE WELL INTO THE 70S WITH BOTH THE ECWMF AND
THE GFS INDICATING +12 C AT 850MB/S.
HAVE DRY CONDITIONS IN ALL FORECAST PERIODS EXCEPT WEDNESDAY AND
WEDNESDAY NIGHT OF THE UPCOMING WEEK. THE ECWMF STILL BRINGS IN A
SHORTWAVE TROUGH ALOFT ALONG WITH SOME MOISTURE...70-80PCT IN THE
1000-700MB LAYER. ONLY HAVE A 20PCT CHANCE OF LIGHT RAIN SHOWERS WED
AND WED NIGHT AT THIS POINT. WE WILL WATCH TRENDS WITH THIS WEAK
SYSTEM AND NUDGE PROBABILITIES FOR PRECIPITATION ACCORDINGLY.
OVERALL...SURFACE HIGH PRESSURE WILL BE IN PLACE DURING THE LONG
TERM WITH NO SIGNIFICANT LOW PRESSURE SYSTEMS OR FRONTAL PASSAGES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 754 AM EDT SAT APR 25 2015
VFR WEATHER IS FORECAST BOTH TODAY AND TONIGHT ACROSS SOUTHWEST
LOWER MICHIGAN. THE LOWER CEILINGS AND RAIN SHOULD REMAIN SOUTH OF
THE TAF SITES TODAY. CEILINGS OF 4000-7000FT AT DAYBREAK SHOULD
LIFT TO 8000-10000FT THIS AFTERNOON AND THEN SCATTER AND CLEAR
THIS EVENING. MAINLY CLEAR SKIES ARE EXPECTED OVERNIGHT.
WINDS FROM THE EAST AT 8-15 KNOTS CAN BE EXPECTED TODAY BECOMING
NORTHEAST TONIGHT AND SUBSIDING TO AROUND 5 KNOTS.
&&
.MARINE...
ISSUED AT 328 AM EDT SAT APR 25 2015
NO MARINE HEADLINES ARE EXPECTED FOR THE NEXT FEW DAYS. WE WILL HAVE
BREEZY CONDITIONS HOWEVER WITH WINDS JUST A NOTCH BELOW SMALL CRAFT
ADVISORY CRITERIA AROUND 15 TO 20 KNOTS LIKELY THROUGH MON. WINDS
SHOULD TEND TO DROP OFF TOWARD THE MID PORTION OF NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 1157 AM EDT SAT APR 25 2015
RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE STEADY OR SLOWLY
FALLING. RAIN IS POSSIBLE ACROSS SOUTHERN LOWER MICHIGAN SOUTH OF
INTERSTATE 96 INTO TONIGHT. ACCUMULATIONS SHOULD BE UNDER A QUARTER
OF AN INCH. DRY WEATHER THEN RETURNS THROUGH THE WEEK. BRIEF RISES
ARE POSSIBLE ON THE SOUTHERN RIVERS... BUT RIVER FLOODING IS NOT
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...63
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1146 AM EDT SAT APR 25 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 328 AM EDT SAT APR 25 2015
LIGHT RAIN SCATTERED AROUND THE AREA EARLY THIS MORNING WILL
DIMINISH AND MOVE SOUTH OF THE AREA DURING THE DAY TODAY. SKIES WILL
THEN CLEAR OUT FROM NORTH TO SOUTH LATER IN THE DAY. HIGH PRESSURE
WILL THEN BUILD IN ACROSS THE AREA FOR THE DAY ON SUNDAY...BRINGING
A COOL AND NICE DAY TO THE AREA.
THE FIRST PORTION OF THE UPCOMING WEEK LOOKS TO BE MAINLY DRY. SOME
CLOUDS MAY ROTATE IN FROM THE NE ON MONDAY AS A WAVE OF LOW PRESSURE
MOVES BY JUST EAST OF THE STATE. THE NEXT CHANCE OF RAIN WILL THEN
COME ON WEDNESDAY. TEMPERATURES WILL GRADUALLY MODERATE TO NEAR
AVERAGE...AND POTENTIALLY ABOVE AVERAGE LATE NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1145 AM EDT SAT APR 25 2015
WILL KEEP THE CHANCE OF LIGHT RAIN THIS AFTERNOON LIMITED TO AREAS
SOUTH OF A LINE FROM ROUGHLY HOLLAND TO JACKSON. LATEST SHORT
RANGE GUIDANCE SUCH AS THE HRRR AND RADAR TRENDS SUPPORT THIS
IDEA.
THE CLOUD FCST IS A BIT TRICKY NORTH OF I-96 AS LATEST VISIBLE
IMAGE SHOWS SOME THINNING TAKING PLACE IN THE MID CLOUD DECK. WILL
HAVE SKIES BECOMING PTLY TO MSTLY SUNNY UP NORTH BUT REMAINING
MOSTLY CLOUDY NEAR AND SOUTH OF I-96. WARMEST HIGH TEMPS THIS
AFTERNOON SHOULD WEST OF HIGHWAY 131 AND NORTH OF I-96 WHERE
READINGS MAY APPROACH LATER TODAY 60 DEPENDING ON AMOUNT OF
CLEARING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EDT SAT APR 25 2015
THE ONLY REAL CHALLENGE IN THE SHORT TERM IS DEALING WITH THE RAIN
CHCS DURING THE DAY TODAY WITH THE UPPER SYSTEM TRYING TO MOVE INTO
THE AREA.
THE TREND IN THE LATEST DATA ALL POINTS TOWARD ALMOST ALL
OF THE RAIN MISSING THE CWFA AFTER THE LINGERING LIGHT RAIN EARLY
THIS MORNING. THE UPPER TROUGH DROPPING INTO THE AREA ON THE WRN
FLANK OF THE UPPER LOW NEAR MAINE HAS TRENDED QUICKER/STRONGER AND
IS DEFLECTING THE PLAINS LOW FURTHER SOUTH. LATEST SATELLITE IMAGERY
APPEARS TO SUPPORT THE LIMIT IN NORTHWARD PROGRESS OF THE LOW IN THE
PLAINS. WE HAVE LEFT A SLIGHT CHC OF RAIN FOR THE DAYLIGHT HOURS
ALONG/SOUTH OF I-94.
ONCE THE TROUGH MOVES THROUGH THIS AFTERNOON...SKIES WILL CLEAR OUT
FROM NORTH TO SOUTH ACROSS THE AREA. WE WILL SEE A QUIET AND DRY
PERIOD SETTLE IN FOR TONIGHT THROUGH SUN NIGHT. THIS WILL BRING A
MILDER DAY ON SUN WITH A DECENT AMOUNT OF SUNSHINE. WE COULD BE
LOOKING AT A COUPLE OF NIGHTS/MORNINGS WITH SOME FROST AND POSSIBLE
HEADLINES FOR LOCATIONS IN THE GROWING SEASON ALREADY AS TEMPS WILL
BE DROPPING INTO THE MID 30S. ENOUGH WIND MAY REMAIN UP SUN NIGHT TO
PREVENT FROST DEVELOPMENT.
WE ARE WATCHING FOR THE POTENTIAL TO POSSIBLY NEED TO ADD SOME LOW
CHCS OF PCPN IN FOR THE DAY ON MON. ANOTHER TROUGH WILL ROTATE SOUTH
THROUGH THE ERN PORTION OF THE STATE ON MON. SOME MOISTURE WILL
ADVECT IN ALSO WITH THE TROUGH. MOISTURE WILL BE RATHER SHALLOW IN
NATURE...SO WE ARE THINKING THAT AN INCREASE IN CLOUD COVER RIGHT
NOW FOR THE ERN SECTION OF THE CWFA IS APPROPRIATE AT THIS TIME.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT APR 25 2015
THE LONG TERM PERIOD LOOKS TO BE QUITE UNEVENTFUL WITH MODERATING
TEMPERATURES AND VERY LITTLE PRECIPITATION. THE UPPER PATTERN WILL
GRADUALLY TREND TOWARDS HIGHER HEIGHTS AND EVEN RIDGING BY NEXT
WEEKEND. 850MB TEMPERATURES WARM FROM AROUND ZERO C MONDAY
NIGHT...TO NEAR +10 C NEXT FRI/SAT. HIGH TEMPERATURES SHOULD WARM
FROM AROUND 60 ON TUESDAY TO AROUND 70 BY NEXT SATURDAY. NEXT
SUNDAY/S HIGHS COULD BE WELL INTO THE 70S WITH BOTH THE ECWMF AND
THE GFS INDICATING +12 C AT 850MB/S.
HAVE DRY CONDITIONS IN ALL FORECAST PERIODS EXCEPT WEDNESDAY AND
WEDNESDAY NIGHT OF THE UPCOMING WEEK. THE ECWMF STILL BRINGS IN A
SHORTWAVE TROUGH ALOFT ALONG WITH SOME MOISTURE...70-80PCT IN THE
1000-700MB LAYER. ONLY HAVE A 20PCT CHANCE OF LIGHT RAIN SHOWERS WED
AND WED NIGHT AT THIS POINT. WE WILL WATCH TRENDS WITH THIS WEAK
SYSTEM AND NUDGE PROBABILITIES FOR PRECIPITATION ACCORDINGLY.
OVERALL...SURFACE HIGH PRESSURE WILL BE IN PLACE DURING THE LONG
TERM WITH NO SIGNIFICANT LOW PRESSURE SYSTEMS OR FRONTAL PASSAGES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 754 AM EDT SAT APR 25 2015
VFR WEATHER IS FORECAST BOTH TODAY AND TONIGHT ACROSS SOUTHWEST
LOWER MICHIGAN. THE LOWER CEILINGS AND RAIN SHOULD REMAIN SOUTH OF
THE TAF SITES TODAY. CEILINGS OF 4000-7000FT AT DAYBREAK SHOULD
LIFT TO 8000-10000FT THIS AFTERNOON AND THEN SCATTER AND CLEAR
THIS EVENING. MAINLY CLEAR SKIES ARE EXPECTED OVERNIGHT.
WINDS FROM THE EAST AT 8-15 KNOTS CAN BE EXPECTED TODAY BECOMING
NORTHEAST TONIGHT AND SUBSIDING TO AROUND 5 KNOTS.
&&
.MARINE...
ISSUED AT 328 AM EDT SAT APR 25 2015
NO MARINE HEADLINES ARE EXPECTED FOR THE NEXT FEW DAYS. WE WILL HAVE
BREEZY CONDITIONS HOWEVER WITH WINDS JUST A NOTCH BELOW SMALL CRAFT
ADVISORY CRITERIA AROUND 15 TO 20 KNOTS LIKELY THROUGH MON. WINDS
SHOULD TEND TO DROP OFF TOWARD THE MID PORTION OF NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 1027 AM EDT FRI APR 24 2015
RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE STEADY OR SLOWLY
FALLING. RAIN IS POSSIBLE ACROSS SOUTHERN LOWER MICHIGAN SOUTH OF
INTERSTATE 96 LATE TONIGHT INTO SATURDAY NIGHT. ACCUMULATIONS SHOULD
BE UNDER A HALF INCH. DRY WEATHER RETURNS LATE SATURDAY NIGHT
THROUGH NEXT WEEK. BRIEF RISES ARE POSSIBLE ON THE SOUTHERN
RIVERS... BUT RIVER FLOODING IS NOT EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...63
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1023 AM CDT SAT APR 25 2015
.UPDATE...
ISSUED AT 1023 AM CDT SAT APR 25 2015
SOUTHEAST FLOW CONTINUES OVER MOST OF THE FORECAST AREA INTO AN
LOW PRESSURE TROUGH SITUATED OVER EASTERN MONTANA. LATEST
MESOSCALE MODELS AND NEW NAM INDICATE LOW LEVEL MOISTURE HANGING
AROUND TODAY...WITH SHOWERS SLOW TO REACH THE WESTERN BORDER. WILL
BUMP UP SKY COVER AND PUSH BACK POPS CHANCES IN THE WEST UNTIL 21
UTC. LOWERED TEMPERATURES JUST A BIT. MAY NEED TO RE-VISIT
TEMPERATURES WITH THE EARLY AFTERNOON UPDATE.
UPDATE
ISSUED AT 627 AM CDT SAT APR 25 2015
NO MAJOR EDITS TO THE GOING FORECAST. STRATUS CONTINUES TO EXPAND
ACROSS THE REGION WITH A MOIST/EASTERLY UPSLOPE FLOW. MODELS TRY
TO ERODE THE CLOUDS AS WE PROGRESS THROUGH THE MORNING...BUT
CLOUDY CONDITIONS THROUGHOUT THE DAY SEEM LIKELY. AREAS OF FOG
PERSIST...WITH LOCALLY DENSE FOG SOUTHWEST WHERE A SPECIAL WEATHER
STATEMENT IS IN EFFECT THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT APR 25 2015
THE MAIN FOCUS FOR THE SHORT TERM THIS MORNING IS LOW CLOUD COVER
AND FOG...LEADING TO AVIATION ISSUES. THE FOCUS THEN TURNS TO
PRECIPITATION ACROSS THE WEST THIS AFTERNOON/EVENING.
EASTERLY UPSLOPE SURFACE FLOW IS BRINGING IN LOW LEVEL MOISTURE
AND RESULTING IN VERY LOW STRATUS AND FOG DEVELOPMENT. CURRENTLY
ABOUT 2/3 OF NORTH DAKOTA IS COVERED. THE STRATUS DECK SHOULD MAKE
IT ALL THE WAY TO MONTANA THIS MORNING. THE LATEST HRRR AND RAP
INDICATE CLOUD COVER AND FOG WILL CONTINUE THROUGH THE EARLY
AFTERNOON HOURS. AS FORCING BECOMES FOCUSED ACROSS WESTERN NORTH
DAKOTA THIS AFTERNOON AND MID-LEVEL FLOW INCREASES AHEAD OF THE
AN UPPER-LEVEL SHORTWAVE TROUGH...CLOUD CEILINGS SHOULD LIFT AND
BEGIN TO SCATTER OUT.
THE LATEST TREND IN THE MODELS IS TO DELAY PRECIPITATION FROM
ENTERING NORTH DAKOTA UNTIL LATE THIS AFTERNOON. CONTINUED THE
TRENDS FROM EARLIER FORECAST UPDATES AND PUSHED PRECIP CHANCES
EVEN FURTHER WESTWARD AND DELAYED ONSET. HOWEVER...UNLIKE
PREVIOUSLY THOUGHT IT DOES APPEAR THAT THERE COULD BE A FEW
ISOLATED THUNDERSTORMS. THE 00 AND 06 UTC MODELS BRING AN AXIS OF
INSTABILITY ACROSS WESTERN NORTH DAKOTA AS FAR NORTH AS THE
CANADIAN BOARDER. AS SUCH INCLUDED THE MENTION OF THUNDERSTORMS
IN THE FORECAST FOR WESTERN NORTH DAKOTA LATE THIS AFTERNOON.
TONIGHT A BAND OF RAIN WILL SLOWLY MOVE ACROSS WESTERN NORTH
DAKOTA...INTO CENTRAL NORTH DAKOTA BY TOMORROW MORNING. WITH VERY
LITTLE PROGRESSION OF THE MAIN FEATURES (SURFACE LOW...LONG WAVE
TROUGH OUT WEST...ETC.) EXPECTED OVER THE NEXT DAY...SEVERAL HOURS
OF MUCH NEED LIGHT RAIN APPEARS LIKELY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT APR 25 2015
AN UNSETTLED WEATHER PATTERN SLOWLY SPREADING FROM WEST TO EAST
SATURDAY THROUGH MONDAY HIGHLIGHTS THE EARLY PORTION OF THE
EXTENDED PERIOD. A SPLIT FLOW REGIME WITH TWO SIGNIFICANT
SHORTWAVE TROUGHS WILL AFFECT THE NORTHERN PLAINS.
FOR SUNDAY-SUNDAY NIGHT...LOW LEVEL MOISTURE WILL CONTINUE TO
SPREAD ACROSS THE REGION. EMBEDDED S/WV IMPULSE ORIGINATING FROM
A DEEP UPPER LOW OVER THE SOUTHERN ROCKIES WILL ROTATE NORTH
ACROSS THE CENTRAL HIGH PLAINS...THEN GETS CAUGHT UP IN THE
NORTHERN STREAM AND SLOWLY MOVES ACROSS MY WEST LIFTING NORTHEAST
BY MONDAY 12Z. BEST VERTICAL MOTION WILL OCCUR ALONG A QUASI-
STATIONARY FRONT INITIALLY ACROSS WESTERN NORTH DAKOTA...AND WILL
MAINTAIN ELEVATED POPS THERE SUNDAY DAYTIME. FRONT STARTS TO
ORIENTATE SOUTHWEST TO NORTHEAST...ALLOWING SHOWERS TO CONTINUE
WEST AND SPREAD INTO THE NORTH CENTRAL SUNDAY NIGHT. SHOULD BE
MAINLY DRY FOR THIS PERIOD ACROSS MY SOUTHEAST.
FOR EARLY MONDAY THROUGH MONDAY NIGHT...NORTHERN STREAM TROUGH
APPROACHES AND PUSHES EAST ACROSS THE STATE...RE-ENERGIZING THE
SURFACE COLD FRONT AND PRODUCING ANOTHER ROUND OF SHOWERS
SPREADING FROM WEST TO EAST. IT WILL BE DURING THIS TIME PERIOD
THAT THE HIGHEST PROBABILITY FOR RAIN WILL OCCUR IN CENTRAL NORTH
DAKOTA.
TOTAL RAINFALL AMOUNTS STILL LOOK LIKE A HALF INCH TO ONE INCH
WEST WITH AROUND A QUARTER OF AN INCH CENTRAL THROUGH MONDAY
NIGHT.
TUESDAY THROUGH FRIDAY...MAINLY DRY AND WARM CONDITIONS AS A
MID/UPPER LEVEL RIDGE SLOWLY MOVES EAST ACROSS THE ROCKIES AND
INTO THE GREAT PLAINS. AFTERNOON HIGHS WEDNESDAY AND THURSDAY
WILL MOSTLY BE IN THE 70S...WITH POSSIBLY SOME LOWER 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1023 AM CDT SAT APR 25 2015
LIFR-IFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THIS MORNING
WITH A SLOW LIFTING TO MVFR LATE MORNING THROUGH EARLY AFTERNOON.
LOW LEVEL EASTERLY WINDS ACROSS WESTERN AND CENTRAL NORTH DAKOTA
WILL REMAIN THROUGH SATURDAY. MAY SEE SOME IMPROVEMENT THIS
AFTERNOON EARLY EVENING EAST...BUT MAY NEED TO EXTEND IFR-MVFR
CEILINGS INTO SATURDAY NIGHT. SHOWERS ARE EXPECTED TO MOVE INTO
THE WEST SATURDAY EVENING BUT REMAIN WEST OF KBIS AND KMOT THROUGH
EARLY SUNDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...NH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
627 AM CDT SAT APR 25 2015
.UPDATE...
ISSUED AT 627 AM CDT SAT APR 25 2015
NO MAJOR EDITS TO THE GOING FORECAST. STRATUS CONTINUES TO EXPAND
ACROSS THE REGION WITH A MOIST/EASTERLY UPSLOPE FLOW. MODELS TRY
TO ERODE THE CLOUDS AS WE PROGRESS THROUGH THE MORNING...BUT
CLOUDY CONDITIONS THROUGHOUT THE DAY SEEM LIKELY. AREAS OF FOG
PERSIST...WITH LOCALLY DENSE FOG SOUTHWEST WHERE A SPECIAL WEATHER
STATEMENT IS IN EFFECT THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT APR 25 2015
THE MAIN FOCUS FOR THE SHORT TERM THIS MORNING IS LOW CLOUD COVER
AND FOG...LEADING TO AVIATION ISSUES. THE FOCUS THEN TURNS TO
PRECIPITATION ACROSS THE WEST THIS AFTERNOON/EVENING.
EASTERLY UPSLOPE SURFACE FLOW IS BRINGING IN LOW LEVEL MOISTURE
AND RESULTING IN VERY LOW STRATUS AND FOG DEVELOPMENT. CURRENTLY
ABOUT 2/3 OF NORTH DAKOTA IS COVERED. THE STRATUS DECK SHOULD MAKE
IT ALL THE WAY TO MONTANA THIS MORNING. THE LATEST HRRR AND RAP
INDICATE CLOUD COVER AND FOG WILL CONTINUE THROUGH THE EARLY
AFTERNOON HOURS. AS FORCING BECOMES FOCUSED ACROSS WESTERN NORTH
DAKOTA THIS AFTERNOON AND MID-LEVEL FLOW INCREASES AHEAD OF THE
AN UPPER-LEVEL SHORTWAVE TROUGH...CLOUD CEILINGS SHOULD LIFT AND
BEGIN TO SCATTER OUT.
THE LATEST TREND IN THE MODELS IS TO DELAY PRECIPITATION FROM
ENTERING NORTH DAKOTA UNTIL LATE THIS AFTERNOON. CONTINUED THE
TRENDS FROM EARLIER FORECAST UPDATES AND PUSHED PRECIP CHANCES
EVEN FURTHER WESTWARD AND DELAYED ONSET. HOWEVER...UNLIKE
PREVIOUSLY THOUGHT IT DOES APPEAR THAT THERE COULD BE A FEW
ISOLATED THUNDERSTORMS. THE 00 AND 06 UTC MODELS BRING AN AXIS OF
INSTABILITY ACROSS WESTERN NORTH DAKOTA AS FAR NORTH AS THE
CANADIAN BOARDER. AS SUCH INCLUDED THE MENTION OF THUNDERSTORMS
IN THE FORECAST FOR WESTERN NORTH DAKOTA LATE THIS AFTERNOON.
TONIGHT A BAND OF RAIN WILL SLOWLY MOVE ACROSS WESTERN NORTH
DAKOTA...INTO CENTRAL NORTH DAKOTA BY TOMORROW MORNING. WITH VERY
LITTLE PROGRESSION OF THE MAIN FEATURES (SURFACE LOW...LONG WAVE
TROUGH OUT WEST...ETC.) EXPECTED OVER THE NEXT DAY...SEVERAL HOURS
OF MUCH NEED LIGHT RAIN APPEARS LIKELY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT APR 25 2015
AN UNSETTLED WEATHER PATTERN SLOWLY SPREADING FROM WEST TO EAST
SATURDAY THROUGH MONDAY HIGHLIGHTS THE EARLY PORTION OF THE
EXTENDED PERIOD. A SPLIT FLOW REGIME WITH TWO SIGNIFICANT
SHORTWAVE TROUGHS WILL AFFECT THE NORTHERN PLAINS.
FOR SUNDAY-SUNDAY NIGHT...LOW LEVEL MOISTURE WILL CONTINUE TO
SPREAD ACROSS THE REGION. EMBEDDED S/WV IMPULSE ORIGINATING FROM
A DEEP UPPER LOW OVER THE SOUTHERN ROCKIES WILL ROTATE NORTH
ACROSS THE CENTRAL HIGH PLAINS...THEN GETS CAUGHT UP IN THE
NORTHERN STREAM AND SLOWLY MOVES ACROSS MY WEST LIFTING NORTHEAST
BY MONDAY 12Z. BEST VERTICAL MOTION WILL OCCUR ALONG A QUASI-
STATIONARY FRONT INITIALLY ACROSS WESTERN NORTH DAKOTA...AND WILL
MAINTAIN ELEVATED POPS THERE SUNDAY DAYTIME. FRONT STARTS TO
ORIENTATE SOUTHWEST TO NORTHEAST...ALLOWING SHOWERS TO CONTINUE
WEST AND SPREAD INTO THE NORTH CENTRAL SUNDAY NIGHT. SHOULD BE
MAINLY DRY FOR THIS PERIOD ACROSS MY SOUTHEAST.
FOR EARLY MONDAY THROUGH MONDAY NIGHT...NORTHERN STREAM TROUGH
APPROACHES AND PUSHES EAST ACROSS THE STATE...RE-ENERGIZING THE
SURFACE COLD FRONT AND PRODUCING ANOTHER ROUND OF SHOWERS
SPREADING FROM WEST TO EAST. IT WILL BE DURING THIS TIME PERIOD
THAT THE HIGHEST PROBABILITY FOR RAIN WILL OCCUR IN CENTRAL NORTH
DAKOTA.
TOTAL RAINFALL AMOUNTS STILL LOOK LIKE A HALF INCH TO ONE INCH
WEST WITH AROUND A QUARTER OF AN INCH CENTRAL THROUGH MONDAY
NIGHT.
TUESDAY THROUGH FRIDAY...MAINLY DRY AND WARM CONDITIONS AS A
MID/UPPER LEVEL RIDGE SLOWLY MOVES EAST ACROSS THE ROCKIES AND
INTO THE GREAT PLAINS. AFTERNOON HIGHS WEDNESDAY AND THURSDAY
WILL MOSTLY BE IN THE 70S...WITH POSSIBLY SOME LOWER 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 627 AM CDT SAT APR 25 2015
LIFR CONDITIONS LIKELY AT KDIK/KJMS...IFR LIKELY AT KBIS/KMOT AND
POSSIBLY AT KISN THROUGH THE MORNING HOURS. LOW LEVEL EASTERLY WINDS
ACROSS WESTERN AND CENTRAL NORTH DAKOTA WILL REMAIN THROUGH
SATURDAY. AS A RESULT LOW LEVEL CLOUDS AND FOG WILL PERSIST THROUGH
THE MORNING HOURS ACROSS THE AREA...AND BEGIN TO LIFT/SCATTER WEST
TO EAST THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AJ
LONG TERM...NH
AVIATION...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1051 AM CDT SAT APR 25 2015
.UPDATE...
MESOSCALE MODELS AND UPDATED SYNOPTIC MODELS CONTINUE TO KEEP THE
MAIN AREA OF RAIN JUST SOUTH OF THE AREA TODAY. THE BEST UPWARD
VERTICAL MOTION WITH THE PASSING 500 MB SHORTWAVE TROUGH TO THE
SOUTH...AND LOW TO MID LEVEL FRONTOGENESIS RESPONSE...REMAINS IN
THIS AREA.
SEEING SOME LIGHT SHOWERS DEVELOP IN THE FAR SOUTHERN COUNTIES...SO
WILL ADJUST POPS FOR THOSE FOR THE NEXT FEW HOURS. WILL LEAVE IN
GENERALLY LOWER END POPS FOR THE SOUTHERN COUNTIES INTO MIDDLE
AFTERNOON...BEFORE TRENDING DRY TOWARD SUNSET. CLOUDS WILL LINGER
ACROSS THE SOUTH THIS AFTERNOON...WITH NORTHERN AREAS POSSIBLY
SEEING SOME BREAKS LATER THIS AFTERNOON.
EAST NORTHEAST WINDS WILL REMAIN GUSTY WITH THE TIGHT PRESSURE
GRADIENT. TEMPERATURES LOOK TO REMAIN IN THE 40S LAKESIDE...TO THE
LOWER 50S IN THE NORTHWEST...WHERE SOME BREAKS IN THE CLOUDS MAY
OCCUR LATER TODAY. MAY HAVE TO LOWER HIGHS SOME MORE IN THE SOUTH
WHERE CLOUDS WILL LINGER.
WOOD
&&
.AVIATION/18Z TAFS/...
MAY SEE LIGHT SHOWERS AT KENOSHA INTO EARLY THIS AFTERNOON...WITH
LOWER CHANCES AT THE OTHER TAF SITES...AS A TROUGH OF LOW
PRESSURE PASSES TO THE SOUTH OF THE REGION. GUSTY EAST NORTHEAST
WINDS WITH SHIFT NORTHEAST THIS AFTERNOON...WITH VFR CATEGORY
CEILINGS.
NORTHEAST WINDS WILL WEAKEN SOMEWHAT TONIGHT INTO SUNDAY...AS HIGH
PRESSURE AXIS MOVES INTO THE REGION. NORTHEAST WINDS AT 1500 FEET
ABOVE GROUND LEVEL MAY LINGER AROUND 30 KNOTS TONIGHT...BUT NOT
ENOUGH OF A WIND SPEED DIFFERENCE FROM THE SURFACE TO REQUIRE LOW
LEVEL WIND SHEAR MENTION IN TAFS.
CLOUDS WILL GRADUALLY DIMINISH FROM NORTH TO SOUTH ACROSS THE
AREA THIS EVENING...WITH MOSTLY CLEAR SKIES EXPECTED LATER TONIGHT
INTO SUNDAY.
WOOD
&&
.MARINE...
SEVERAL VESSELS PARKED IN MILWAUKEE AND RACINE HARBORS REPORTING
SUSTAINED WINDS OF 18 TO 20 KNOTS FROM THE ENE THIS MORNING.
FURTHER TIGHTENING OF THE PRESSURE GRADIENT IS EXPECTED TODAY AS
SFC LOW PRESSURE MOVES FROM MISSOURI E-SE TOWARD TN VALLEY REGION.
HOWEVER...BOTH RAP AND 12Z NAM12 SHOWING WEAK HIGH PRESSURE RIDGE
BUILDING ALONG LAKE MI WEST COAST THIS AFTN WHICH COULD PARTIALLY
BE A RESULT OF COLD LAKE MI TEMPS. RETURN OF MODIS IMAGERY
MEASURED LAKE MI SEA SURFACE TEMPS IN THE LOW 40S ON FRI.
WL CONTINUE SMALL CRAFT ADVY WITH SRN ZONES LIKELY TO HAVE MORE
FREQUENT WIND GUSTS EXCEEDING 22KTS TODAY INTO TONIGHT.
HOWEVER...PERSISTENT N TO NE FETCH WILL CAUSE WAVE HEIGHTS TO
BUILD TO 3 TO 5 FEET OVER ALL OF THE NEARSHORE. MAY BE ABLE TO
TRIM BACK END TIME OF SMALL CRAFT ADVY WITH NEW AFTN FORECAST AS
WINDS AND WAVES LIKELY TO SUBSIDE LATER TONIGHT.
MBK
&&
.PREV DISCUSSION... /ISSUED 311 AM CDT SAT APR 25 2015/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
THE 250 MB UPPER TROUGH WILL MOVE EAST NORTHEAST FROM KANSAS...
REACHING THE UPPER OHIO VALLEY BY EVENING. AS IT DOES THE UPPER
JET IS SUPPRESSED SOUTH...WHILE THE MAIN JET MAX MOVES OFF TOWARD
THE MID ATLANTIC STATES. LITTLE IN THE WAY OF UPPER DIVERGENCE
ACROSS SOUTHERN WISCONSIN. A STRONGER MID LEVEL TROUGH AS 500 MB
PUSHES MAINLY EAST BEFORE THE NORTHEAST U.S. AND SOUTHEAST CANADA
TROUGH ROTATES ACROSS THE NORTHERN GREAT LAKES FROM THE NORTHEAST.
MOST OF THE 700 MB UPWARD MOTION IS ALONG AND JUST SOUTH OF THE
ILLINOIS BORDER TODAY.
THE 700 MB RH IS SATURATED ALONG THE SOUTH TIER OF COUNTIES THIS
MORNING...THEN DRIES FROM THE NORTH THIS AFTERNOON AND ESPECIALLY
TONIGHT. THE 850 MB RH DRIES THIS MORNING NORTH AREAS...THEN ACROSS
THE SOUTH THIS AFTERNOON. THE 850 MB LOW WEAKENS AND ELONGATES AS IT
MOVES EAST...THEN SAGGING SOUTH THIS AFTERNOON. THE EAST 850 MB
WINDS INCREASE THIS MORNING...THEN WEAKEN SLIGHTLY AS THEY TURN
NORTHEAST THIS AFTERNOON. THE SURFACE WINDS ALSO INCREASE THIS
MORNING...BUT REMAIN MODERATE THIS AFTERNOON.
LOW PRESSURE MOVING ACROSS THE OHIO RIVER VALLEY AND KENTUCKY REGION
TODAY MAY BRUSH THE FAR SOUTH WITH LIGHT RAIN. THE NAM...HRRR AND
THE ARW HIGH RES MODELS KEEP PRECIPITATION MAINLY SOUTH OF
WISCONSIN...ALTHOUGH THE ARW NMN DOES HAVE SOME LIGHT PRECIPITATION
OVER THE SOUTHERN TIER AND A BIT MORE NORTH OFF LAKE MICHIGAN.
THE GFS IS THE FARTHEST NORTH OF THE MODELS...WITH THE 00Z ECMWF A
BIT FARTHER NORTH THAN THE NAM. WILL BE CUTTING BACK ON POP
VALUES...ESPECIALLY NORTH HALF TODAY.
LONG TERM...
SUNDAY THROUGH THURSDAY... FORECAST CONFIDENCE HIGH.
DRY AIR AND MID LEVEL RIDGING WILL NOSE INTO THE WESTERN GREAT LAKES
EARLY NEXT WEEK AS A SPRAWLING CLOSED UPPER LOW OVER NEW ENGLAND
SHIFTS EAST. SURFACE HIGH PRESSURE WILL TAKE HOLD OF THE UPPER
MIDWEST AND GREAT LAKES THROUGH THURSDAY AND BRING A PLEASANT
STRETCH OF WEATHER TO SOUTHERN WI. THERE WILL BE A STEADY BREEZE OUT
OF THE NORTH THROUGH THIS PERIOD... BUT WITH THE WEAK PRESSURE
GRADIENT WE CAN EXPECT A LAKE BREEZE TO DEVELOP EACH DAY. INLAND
TEMPS WILL BE IN THE 60S FOR MOST OF THIS PERIOD WHILE LAKESHORE
TEMPS WILL BE STUCK IN THE 50S.
A MID LEVEL SHORTWAVE WILL DROP DOWN THROUGH WI TUE AFTERNOON/
EVENING. THE ECMWF ALLOWS THIS SHORTWAVE TO DEVELOP INTO A CLOSED
UPPER LOW OVER THE OHIO RIVER VALLEY...WHILE THE GFS DROPS IT INTO
THE SOUTHEAST STATES ON THE HEELS OF AN EXITING UPPER LOW. THE GFS
IS MAINTAINING A DRY FORECAST FOR TUE NIGHT/WED WHILE THE ECMWF IS
SHOWING LIGHT RAIN OVER SOUTHERN WI. THUS... KEPT SLIGHT CHANCES IN
THE FORECAST.
FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE MEDIUM.
THE ECWMF IS SHOWING A MORE ZONAL UPPER JET ALONG THE US/CANADIAN
BORDER THU NIGHT THROUGH SATURDAY. THE GFS IS SHOWING A LARGER RIDGE
OVER THE NORTHERN PLAINS/UPPER MIDWEST. THE GFS IS QUICKEST TO DRAW
VERY WARM AIR INTO SOUTHERN WI LATE NEXT WEEK. THE ECMWF IS DELAYED
WITH THE WARMING SINCE IT IS SHOWING RAIN CHANCES FRIDAY AND AGAIN
SATURDAY AFTERNOON WITH WEAK SHORTWAVES AND WARM AIR ADVECTION. IF
THE GFS PANS OUT... MAX TEMPS SHOULD BE IN THE UPPER 70S FOR NEXT
WEEKEND.
AVIATION/12Z TAFS/...
LOW PRESSURE MOVING ACROSS THE OHIO RIVER VALLEY AND KENTUCKY REGION
TODAY MAY BRUSH THE FAR SOUTH WITH LIGHT RAIN.
MAINLY VFR CIGS/VSBYS...ALTHOUGH SOME MVFR CIGS POSSIBLE FAR SOUTH
TOWARDS THE ILLINOIS BORDER...AND ALONG LAKE MICHIGAN. CIGS WILL
RISE AND CLOUDS CLEAR FROM THE NORTH TONIGHT AS THE LOW MOVES EAST
AND HIGH PRESSURE BUILDS TOWARD LAKE SUPERIOR.
MARINE...
EAST NORTHEAST WINDS ARE EXPECTED TO INCREASE TODAY INTO THIS
EVENING. RESULTING PERSISTENT NORTHEAST WINDS SHOULD BRING WAVES
ABOVE SMALL CRAFT ADVISORY CONDITIONS. A SMALL CRAFT ADVISORY IS IN
EFFECT FOR TODAY AND TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM CDT SUNDAY FOR LMZ643>646.
&&
$$
UPDATE...WOOD/MBK
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ SUNDAY
THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
927 AM CDT SAT APR 25 2015
.UPDATE...
ISSUED AT 927 AM CDT SAT APR 25 2015
LOOKING AT THE TRENDS IN THE 25.12Z RAP AND 25.13Z HRRR IT APPEARS
ANY CHANCES FOR RAIN TODAY WILL BE LIMITED TO THE VERY SOUTHERN
PARTS OF THE AREA. THE RAP INDICATES THERE IS A WEAK SHORT WAVE
TROUGH ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW THAT COULD
PRODUCE SOME WEAK FORCING OVER THE AREA BEFORE SHIFTING OFF TO THE
EAST DURING THE MID AND LATE AFTERNOON HOURS. SOME WEAK
FRONTOGENESIS IN THE 850-700 MB LAYER COULD ALSO ROTATE BACK NORTH
INTO THE AREA AROUND 18Z. TRIMMED THE NORTHERN EXTENT OF THE RAIN
CHANCES FOR THE REST OF THE DAY TO CONFINE THEM TO THE FAR
SOUTHERN AREAS. ALSO LOWERED THEM DOWN FROM THE 60 TO 70 PERCENTS
TO ABOUT 30 OR 40 PERCENT. THE RAP SHOWS ALL THE CAPE REMAINING
WELL TO THE SOUTH WITH NO ELEVATED CAPE IN EITHER THE KDBQ OR KBLR
FORECAST SOUNDINGS SO HAVE DROPPED THE THUNDER MENTION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT SAT APR 25 2015
FORECAST FOCUS IN THE SHORT TERM IS THE RAIN THREAT TODAY. CLOSED
CIRCULATION SPINNING THROUGH KS EARLY THIS MORNING...HEADING EAST
AND WEAKENING THROUGH THE DAY TODAY. DEFORMATION AND FRONTOGENETIC
FOCUS ON THE NORTHERN EDGE OF THIS SYSTEM WILL SPREAD RAIN AND
EMBEDDED THUNDERSTORMS ACROSS IA AND NORTHERN IL. MAIN DILEMMA IS
HOW FAR NORTH RAIN WILL GET. VARIOUS MODEL SOLUTIONS OVER THE PAST
SEVERAL DAYS HAD BEEN SUGGESTING RAIN WOULD SPREAD NORTH AS FAR
AS THE I-90 CORRIDOR. BUT THE LAST FEW RUNS HAVE NOW SHIFTED THAT
FOCUS FURTHER SOUTH. LOOKING AT THE FORCING AND THE INFLUX OF MORE
DRY LOW LEVEL AIR ON EAST/NORTHEAST WINDS SUPPORT A TIGHTER
RAIN/NO-RAIN GRADIENT AND THE SOUTHWARD SHIFT. THIS TREND IS
ALREADY BORNE OUT LOOKING AT OVERNIGHT RADAR LOOPS SHOWING THE
DIMINISHING TREND. SO MOVED THE FORECAST IN THIS DIRECTION FOR
TODAY. RAIN THREAT WILL END BY SUNSET AS HIGH PRESSURE OVER MB/ONT
BUILDS SOUTHWARD INTO THE REGION. AIRMASS DRIES AND BOUNDARY LAYER
TEMPERATURES TUMBLE. A CHILLY NIGHT IS ON TAP...ESPECIALLY OVER
OUR TYPICAL COOL AREAS OF CENTRAL WI.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT APR 25 2015
LOOKING INTO THE LONGER TERM...UPPER FLOW PATTERN REMAINS BLOCKED
THANKS TO THE EAST COAST CLOSED LOW WHICH PERSISTS INTO AT LEAST
TUESDAY. THIS KEEPS SURFACE HIGH PRESSURE AND DRY EASTERLY FLOW
POURING INTO THE AREA. A WEAK SHORT WAVE TROUGH DROPS INTO THE
BACK SIDE OF THE UPPER LOW LATE ON TUESDAY. THIS COULD BRING A FEW
LIGHT SHOWERS TO PARTS OF THE AREA...BUT WITH A VERY DRY
ATMOSPHERE THE CHANCES WILL BE QUITE LOW. THE PATTERN TRANSITIONS
TO MORE OF AN OMEGA LOOK BY LATE IN THE WEEK...PUTTING THE AREA
MORE IN THE UPPER RIDGE. THUS...A WARMING TREND IS ON TAP WITH
TEMPERATURES BACK ABOVE NORMAL. THE NEXT SIGNIFICANT CHANCE FOR
ANY RAINFALL LOOKS TO BE NEXT WEEKEND AS THE PERSISTENT SOUTHERLY
FLOW FINALLY GETS ENOUGH MOISTURE INTO THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 632 AM CDT SAT APR 25 2015
MAIN AVIATION CONCERNS ARE THE POSSIBILITY OF MVFR CONDITIONS AT
BOTH THE RST/LSE TAF SITES TODAY. LATEST 11Z SURFACE ANALYSIS
SHOWS LOW PRESSURE OVER EASTERN KANSAS WITH LATEST FOG SATELLITE
PRODUCT INDICATING STRATUS DECK CLOUDS COVERING MUCH OF THE
NORTHERN PLAINS AND GREAT LAKES REGION. LATEST METARS REPORTING
CEILING HEIGHTS GENERALLY IN THE VFR RANGE WITH A FEW
METARS REPORTING MVFR CONDITIONS. THE LATEST 25.06Z GFS/NAM
SUGGEST THE CEILING HEIGHTS TO REMAIN IN THE VFR RANGE. EXPECT
VFR CONDITIONS TO PREVAIL AT TAF BOTH RST/LSE SITES TODAY. HIGH
PRESSURE BUILDS INTO NORTHERN WISCONSIN AND NORTHERN MINNESOTA
AFTER 00Z SUNDAY. DRIER AIRMASS ADVECTS INTO THE REGION AND ALLOWS
SKIES TO CLEAR BY 03Z SUNDAY AT BOTH RST/LSE TAF SITES. WINDS WILL
SHIFT TO THE NORTHEAST AND BECOME LESS THAN 10 KNOTS BY 03Z
SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...04
SHORT TERM...MW
LONG TERM...MW
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
915 AM MST SAT APR 25 2015
.SYNOPSIS...
A STRONG COLD FRONT IS FORECAST TO MOVE INTO THE REGION LATE THIS
AFTERNOON AND EVENING. AHEAD OF THE FRONT...GUSTY AFTERNOON
SOUTHWEST WINDS WILL DEVELOP...STRONGEST IN SOUTHEAST CALIFORNIA AND
THE COLORADO RIVER VALLEY. THE CHANCE OF SHOWERS AND THUNDERSTORMS
WILL ALSO INCREASE LATE TODAY AND TONIGHT...BUT MAINLY ACROSS
PORTIONS OF SOUTHWEST AND SOUTH CENTRAL ARIZONA. LINGERING SHOWERS
ARE EXPECTED SUNDAY OVER EASTERN ARIZONA...WITH CLEARING OVER
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. DRIER AND MUCH WARMER
WEATHER IS EXPECTED NEXT WEEK.
&&
.DISCUSSION...
...POTENT UPPER TROUGH AND FRONTAL PASSAGE ACROSS THE REGION TODAY
WITH STRONG GUSTY WINDS AND THUNDERSTORM CHANCES...
INCOMING UPPER TROUGH CONTINUES TO QUICKLY APPROACH FROM THE
NORTHWEST WITH THE MAIN SHORTWAVE IN EAST-CENTRAL CALIFORNIA. A
SECOND SHORTWAVE TROUGH...EASILY SEEN ON WATER VAPOR IMAGERY MOVING
INTO SOUTHEAST CALIFORNIA...WAS NOT PICKED UP WELL BY THE MODELS AND
MAY GIVE US A BETTER CHANCE OF SHOWERS ACROSS OUR NORTHERN ZONES BY
MID TO LATE AFTERNOON. THE LATEST HRRR RUN SHOWS A BAND OF SHOWERS
QUICKLY DEVELOPING AROUND 21Z ACROSS EASTERN RIVERSIDE COUNTY
CALIFORNIA AND OVER LA PAZ COUNTY ARIZONA AND THEN QUICKLY SPREADING
EASTWARD THROUGH SOUTH-CENTRAL ARIZONA. MODEL POP GUIDANCE STILL IS
A BIT ON THE LOW SIDE...BUT FEEL OUR A BIT MORE AGGRESSIVE FORECAST
POPS ARE JUSTIFIED BASED ON IMPRESSIVE WATER VAPOR SHORTWAVE TROUGH
SIGNATURE. WINDS HAVE YET TO PICK UP MUCH...BUT ONCE THIS FIRST
TROUGH SLIDES EASTWARD THIS AFTERNOON...GUSTY WINDS WILL DEVELOP
OVER SOUTHEAST CALIFORNIA AND THEN A BIT LATER OVER SOUTH-CENTRAL
ARIZONA. BEST CHANCES FOR RAIN AND POTENTIALLY A FEW THUNDERSTORMS
STILL SEEMS TO BE CENTERED AROUND 06Z TONIGHT OVER SOUTH-CENTRAL
ARIZONA AS THE MAIN SHORTWAVE TROUGH SWINGS THROUGH.
&&
.PREVIOUS DISCUSSION...
TODAY THROUGH SUNDAY...
REGIONAL WEATHER BALLOON SOUNDINGS FRIDAY EVENING CONTINUED TO SHOW
A RELATIVELY MOIST BOUNDARY LAYER ABOUT 6 TO 7000 FEET DEEP
EXTENDING FROM SOUTHERN CA TO SOUTHWEST AND SOUTH CENTRAL AZ. THIS
MOISTURE IS SIGNIFICANT RELATIVE TO THE COOLER TEMPS ALOFT...AND
FRONTAL PASSAGE EXPECTED LATE SATURDAY AFTERNOON AND EVENING.
OTHERWISE...A POWERFUL AND FAST MOVING NEGATIVE TILT DIFLUENT TROF
IS STILL FORECAST TO MOVE INTO CENTRAL AZ LATE SATURDAY AFTERNOON
AND EVENING. CURRENT MODELS...SPECIFICALLY THE GFS...IS NOT ONLY A
LITTLE FASTER WITH THE COLD FRONT...BUT IT DEEPENS THE TROF SLIGHTLY
MORE EASTWARD INTO CENTRAL AZ. A VERY PROGRESSIVE UPSTREAM PACIFIC
FLOW PATTERN IS PERHAPS PUSHING THIS SYSTEM FASTER/EASTWARD THAN
EARLIER MODEL RUNS. THEREFORE PRECIP CHANCES ACROSS THE FORECAST
AREA...INCLUDING PHOENIX WILL LIKELY START A LITTLE EARLIER...
MEANING LATE AFTERNOON. THE HEAVIEST PRECIP WITH A CHANCE OF TSTMS
HOWEVER IS SLATED FOR THIS EVENING...AFTER DARK...IN SOUTH CENTRAL
AZ.
FOR TODAY AND TONIGHT...
INCREASING CLOUDS BUT NO PRECIP IS EXPECTED THE FIRST HALF OF THE
DAY. BACKING PRE-FRONTAL WINDS AND WARM ADVECTION AHEAD OF THE COLD
FRONT WILL MAKE FOR A WINDY AFTERNOON... WITH THE STRONGEST WINDS IN
SOUTHEAST CA/COLORADO RIVER WHERE A WIND ADVISORY IS POSTED FOR
GUSTS BETWEEN 35 AND 45 MPH.
THE COLD FRONT BY 5 PM LOCAL TIME WILL HAVE JUST MOVED ACROSS THE
COLORADO RIVER...THEN INTO PHOENIX AREA BY 8 PM. THE BEST CHANCE OF
SHOWERS AND THUNDERSTORMS BY 5 PM WILL DEVELOP JUST NORTHWEST AND
NORTH OF BLYTHE CA ALONG THE COLORADO RIVER...AND OVER PORTIONS OF
LA PAZ COUNTY. SHOWERS AND TSTMS DEVELOP ALONG THE COLD FRONT IN
PHOENIX BY 8 PM. IF THUNDERSTORMS DEVELOP...THEIR FAST MOVEMENT
COMBINED WITH PRECIP FALLING THROUGH 20-30 KNOT 850-700 MB
SOUTHWESTERLY WINDS COULD CAUSE SUDDEN GUSTS TO PERHAPS 45 MPH.
SINCE THIS IS A FAST MOVING SYSTEM...MOST SHOWERS BY 5 AM SUN WILL
BE CONFINED TO AREAS GENERALLY FROM PHOENIX EASTWARD. SAME FOR THE
SUNDAY AFTERNOON/EARLY EVENING PERIOD.
SUNDAY NIGHT...RAPID CLEARING IS EXPECTED.
MONDAY THROUGH FRIDAY...
DRY NORTHERLY FLOW WILL DEVELOP MONDAY AND TUESDAY FOLLOWED BY A
BUILDING RIDGE OVER THE REGION WEDNESDAY AND THURSDAY. MUCH WARMER
TEMPERATURES ARE FORECAST WEDNESDAY WITH NEAR 100 DEGREE HEAT ON THE
WARMEST DESERTS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
APPROACHING UL TROUGH AND COLD FRONT WILL INCREASE WINDS BEGINNING
LATE AM GNLY POST 17Z...BECOMING GUSTY UP TO 25KT OR SO DURING THE
AFTERNOON...EVEN STRONGER TO 30KT SATURDAY EVENING. EXPECT THE
STRONGEST WINDS IN A BURST RIGHT ALONG PASSING COLD FRONT. SOME
TIMING DIFFERENCES REMAIN BETWEEN MODEL FCSTS...BUT LIKELY WINDOW OF
FROPA AND STRONGEST WEST WINDS AROUND 26/02-04Z WINDOW.
PRECIPITATION CHANCES ALSO INCREASE AFTER 21Z...WITH SCATTERED
SHOWER/THUNDERSTORM COVERAGE BEGINNING OVER THE WESTERN DESERTS. VCSH
WILL BEGIN TO FILL IN AROUND PHX METRO PERIPHERY AFTER 26/00Z...WITH
SHOWERS STARTING EARLIER FOR KSDL AND KIWA BEFORE KPHX. CHANCE OF
THUNDER POSSIBLE AS WELL WITH THIS STRONG SYSTEM...SO INCLUDED
OVERNIGHT MENTION OF -TSRA POST-MIDNIGHT LOCAL 26/07Z. CIGS
STARTING OFF IN THE AFTERNOON 7-9KFT BEFORE DROPPING INTO THE 3-5KFT
RANGE WITH ONSET OF STEADY PRECIP LATE IN THE EVENING.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
APPROACHING UL TROUGH WILL PERSIST STRONG WINDS STEADILY INCREASING
AFTER 25/16Z...PEAK GUSTS UP TO 40KT WILL BE COMMON ACROSS THE AREA
BY LATE AFTERNOON CONTINUING INTO THE EVENING HOURS. PERIODS OF
BLOWING DUST REDUCING VISIBILITY DOWN TO 2SM WILL BE COMMON WITH THE
STRONGER WINDS...ESPECIALLY ACROSS IMPERIAL COUNTY AND NEAR YUMA.
12Z TAFS TAKE AIRFIELD VSBYS DOWN TO 5SM BUT CANNOT RULE OUT LOCALLY
LOWER VALUES FOR SHORTER PERIODS. SLANT VSBYS LIKELY IMPACTED DUE TO
LOFTED DUST. THE STRONGEST WINDS TO ABATE LATER INTO THE EVENING BUT
REMAIN ELEVATED IN THE 10-15KT RANGE WITH GUSTS STILL TOWARDS 20KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
IN THE WAKE OF THE DEPARTING TROUGH...NEXT WEEK WILL SEE THE ARRIVAL
OF A STRONG UPPER RIDGE OVER THE SOUTHWESTERN CONUS FROM MONDAY
THROUGH MOST OF THE WEEK. TEMPERATURES WILL WARM SUBSTANTIALLY AND
APPROACH THE TRIPLE DIGIT MARK FOR THE LATTER PART OF THE WEEK.
AFTERNOON HUMIDITIES WILL DROP INTO THE LOWER TEENS AND UPPER SINGLE
DIGITS WITH FAIR OVERNIGHT RECOVERIES EXPECTED. WINDS WILL BE GNLY
LIGHT AND SHOULD FOLLOW TYPICAL DIURNAL PATTERNS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WIND ADVISORY FROM 1 PM TO 9 PM PDT TODAY FOR CAZ030>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/LEINS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
433 PM EDT SAT APR 25 2015
...ISOLATED SEVERE STORMS POSSIBLE THROUGH THIS EVENING...
.NEAR TERM [THROUGH TONIGHT]...
THE NOON EDT REGIONAL SURFACE ANALYSIS SHOWED A WEAK WARM FRONT
EXITING OUR FORECAST AREA TO THE NORTHEAST (ACROSS CENTRAL GA), AND
A RIDGE ALONG THE WEST FL COAST. THERE WAS A 1008 MB LOW OVER
SOUTHEAST LA, ASSOCIATED WITH AN MCS. VAPOR IMAGERY AND UPPER AIR
DATA SOWED A +PV ANOMALY (NEAR THE AFOREMENTIONED WARM FRONT)
EXITING OFF THE SOUTHEAST COAST. IT WAS THIS FEATURE (ALONG WITH THE
WARM FRONT) THAT HELPED TO GENERATE THE DEEP MOIST CONVECTION THIS
MORNING. AS OF 3 PM EDT, THE STORMS OVER OUR REGION HAD DECREASED
AND WERE RATHER ISOLATED, BEING PRIMARILY DRIVEN BY MESOSCALE
BOUNDARY INTERACTIONS AND A CONDITIONALLY UNSTABLE AIR MASS.
THERE WAS ANOTHER +PV ANOMALY OVER SOUTHEAST LA THAT WILL
TRANSLATE QUICKLY EASTWARD THROUGH THIS EVENING. WE EXPECT SOME OF
THE DEEP MOIST CONVECTION ASSOCIATED WITH THIS FEATURE (CURRENTLY
THE MCS IN SOUTHEAST LA) TO REACH OUR FORECAST AREA BY LATE
AFTERNOON AND EARLY THIS EVENING.
RECENT RAP ANALYSES STILL SHOWED 0-6 BULK SHEAR VALUES OF 50 TO 60
KT ACROSS OUR REGION. COUPLED WITH A MOIST, MODERATELY UNSTABLE
AIR MASS, THERE COULD STILL BE ISOLATED SEVERE STORMS ACROSS OUR
REGION THROUGH SUNSET. DAMAGING WIND GUSTS AND HAIL ARE THE MAIN
THREATS, BUT THERE IS JUST ENOUGH 0-1 KM SHEAR (25 KT) TO SUPPORT A
LOW-END TORNADO THREAT AS WELL, ESPECIALLY ALONG MESOSCALE
BOUNDARIES. AFTER SUNSET THE CAPE WILL DECREASE AND THE FORCING WILL
DIMINISH, SO WE EXPECT THE RAIN TO TAPER OFF FROM WEST TO EAST BY
MIDNIGHT.
.SHORT TERM [SUNDAY THROUGH MONDAY NIGHT]...
AT UPPER LEVELS, THE ELONGATE E-W ORIENTED TROUGH OVER NEW ENGLAND
AND THE GREAT LAKES WILL AMPLIFY SOUTHWARD AS IT SWEEPS OFF THE EAST
COAST. MEANWHILE, AN UPPER LEVEL LOW WILL CUT OFF OVER NEW MEXICO ON
SUNDAY AND MOVE EAST TO OKLAHOMA BY MONDAY NIGHT. THE GULF COAST
REGION WILL REMAIN UNDER FAIRLY ZONAL FAST FLOW WITH THE SEEMINGLY
EVER-PRESENT SUBTROPICAL JET FIRMLY IN PLACE ON SUNDAY. THIS
FEATURE WILL LIFT TEMPORARILY NORTHWARD ON MONDAY. AT THE
SURFACE, A COLD FRONT WILL DROP SOUTH FROM THE TENNESSEE VALLEY ON
SUNDAY TO OFF OUR COASTLINE BY MONDAY. ENOUGH DRY AIR WILL WORK
ITSELF INTO OUR NORTHERN ZONES BY SUNDAY TO PRECLUDE CONVECTIVE
DEVELOPMENT THERE. AREAS SOUTH OF A DOTHAN TO TIFTON LINE WILL SEE
ISOLATED TO SCATTERED STORM DEVELOPMENT ON SUNDAY AFTERNOON WITH
COVERAGE INCREASING AS YOU HEAD SOUTH. 50-55 KNOTS OF DEEP LAYER
SHEAR WILL OVERLAY SBCAPES IN EXCESS OF 1200 J/KG (ALONG AND S OF
I-10) WHICH WILL SUPPORT ORGANIZED CONVETION AND ANOTHER SEVERE
WEATHER THREAT. SPC HAS THE ENTIRE FORECAST AREA OUTLINED FOR A
MARGINAL RISK OF SEVERE STORMS. HOWEVER, WE FEEL THAT THE BEST
THREAT FOR SEVERE WILL BE LIMITED TO THE SOUTHERN HALF OF THE
FORECAST AREA WITH DAMAGING WIND AND HAIL THE PRIMARY THREAT. BY
MONDAY, INCREASED DRY AIR AND LOWER CAPE WILL PRECLUDE A SEVERE
WEATHER THREAT, ALTHOUGH ISOLATED TO SCATTERED STORMS ARE STILL
POSSIBLE SOUTH OF THE FLORIDA LINE.
.LONG TERM [TUESDAY THROUGH NEXT SATURDAY]...
THE UPPER LOW OVER THE PLAINS WILL OPEN UP AS IT MOVES EAST
ACROSS THE MISSISSIPPI VALLEY, BUT SOME REMNANT ENERGY WILL BE
LEFT BEHIND AND EVENTUALLY DEEPEN INTO ANOTHER CUT-OFF CLOSED LOW
SOMEWHERE IN THE VICINITY OF TX OR LA. THERE ARE LARGE DIFFERENCES
IN HOW THE MODELS EVOLVE THE LOW EASTWARD WITH THE GFS MORE
PROGRESSIVE THAN THE EURO. THERE WILL BE A SURFACE REFLECTION OF
THIS FEATURE SOMEWHERE IN THE VICINITY OF THE NORTH CENTRAL GULF
COAST BY TUESDAY. AGAIN, THERE ARE MODEL DIFFERENCES AS TO WHAT
LATITUDE THE LOW WILL TRACK EWD ALONG. A MORE NORTHERLY TRACK
WOULD FAVOR MORE THUNDERSTORMS AND SEVERE THREAT WHILE A MORE
SOUTHERLY ROUTE WOULD MEAN MAINLY SHOWERS. THESE DETAILS WILL NEED
TO BE WORKED OUT IN FUTURE FORECASTS WHEN WE WILL HOPEFULLY SEE A
MODEL CONSENSUS DEVELOP. ONE THING THAT IS CERTAIN IS THAT THE THE
TUESDAY THROUGH WEDNESDAY PERIOD WILL BE THE MOST UNSETTLED WITH
HIGHEST POPS. LATER IN THE WEEK, THE EURO DRIES US OUT AND THE GFS
DEVELOPS ANOTHER GULF LOW. TO ADDRESS THE UNCERTAINTY WE HAVE
SLIGHT TO LOW CHANCE POPS IN FOR FRIDAY THROUGH SATURDAY.
&&
.AVIATION...
[THROUGH 18Z SUNDAY] MVFR TO VFR CONDITIONS THIS EVENING WILL
DETERIORATE TO IFR OVERNIGHT AS LOW CIGS SET IN AROUND MIDNIGHT.
LOW VSBYS WILL ALSO BE POSSIBLE AT TLH AND VLD AROUND SUNRISE.
WINDS FROM THE WEST-SOUTHWEST WILL BE QUITE GUSTY TODAY AND
TOMORROW AT MOST SITES, AROUND 10-15 KTS WITH GUSTS TO AROUND 20
KTS OCCASIONALLY, THOUGH THEY WILL BE LIGHTER OVERNIGHT.
&&
.MARINE...
WINDS WILL INCREASE TO CAUTIONARY LEVELS TONIGHT AS A COLD FRONT
DRIFTS SOUTH TOWARD THE WATERS. THESE WINDS WILL REMAIN ELEVATED
ACROSS THE EASTERN WATERS INTO SUNDAY NIGHT. THE FRONT WILL SLIDE
SOUTH IN THE WATERS BY MONDAY MORNING BRIEFLY SWITCHING WINDS TO
OFFSHORE. THE FORECAST FROM TUESDAY ONWARD IS HIGHLY DEPENDENT ON
THE DEVELOPMENT OF AND TRACK OF A GULF LOW THROUGH THURSDAY. FOR
NOW THE FORECAST REFLECTS MODERATE EASTERLY FLOW ON TUESDAY
SWITCHING TO STRONGER NORTHWESTERLY FLOW ON WEDNESDAY. THIS
FORECAST IS SUBJECT TO CHANGE.
&&
.FIRE WEATHER...
MOIST CONDITIONS WILL PERSIST THROUGH THE NEXT FEW DAYS KEEPING
RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS. RAIN CHANCES
REMAIN IN THE FORECAST THROUGH WEDNESDAY...WITH THE POTENTIAL FOR
LOCALLY HEAVY RAINFALL FROM A STRONGER STORM SYSTEM TUESDAY AND
WEDNESDAY.
&&
.HYDROLOGY...
AN ACTIVE WEATHER PATTERN HAS LEFT MANY OF OUR AREA RIVERS IN
ACTION STAGE, WITH A FEW THAT REACHED FLOOD STAGE. THE
CHOCTAWHATCHEE RIVER AT BRUCE AND THE APALACHICOLA RIVER AT
BLOUNTSTOWN ARE THE ONLY TWO SITES REMAINING IN FLOOD STAGE AND
HAVE BOTH PEAKED AND WILL CONTINUE TO FALL OVER THE NEXT FEW DAYS.
ADDITIONAL RAINFALL TODAY AND TOMORROW IS NOT FORECAST TO CAUSE
ANY FURTHER FLOODING, HOWEVER A ROUND OF HEAVY RAIN ON TUESDAY IN
NORTH FLORIDA MAY CAUSE SOME AREA RIVERS TO RISE TO ACTION OR
FLOOD STAGE BY MID-WEEK NEXT WEEK. CURRENTLY THE MOST VULNERABLE
SITES WOULD BE THE CHOCTAWHATCHEE AT BRUCE AND CARYVILLE AND THE
APALACHICOLA RIVER AT BLOUNTSTOWN AGAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 73 89 69 86 64 / 30 30 20 20 30
PANAMA CITY 74 81 71 79 65 / 20 30 20 30 40
DOTHAN 70 87 64 83 59 / 10 10 10 10 20
ALBANY 70 87 64 81 57 / 30 10 10 10 10
VALDOSTA 71 88 66 82 62 / 40 30 20 20 20
CROSS CITY 73 85 69 84 64 / 30 40 30 40 30
APALACHICOLA 75 83 71 81 68 / 20 40 20 40 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 2 AM EDT SUNDAY FOR COASTAL BAY.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...FOURNIER
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...FOURNIER
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...MOORE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
304 PM EDT SAT APR 25 2015
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING A BROAD RIDGING
PATTERN IN PLACE OVER THE EASTERN GULF OF MEXICO AND FLORIDA
PENINSULA. UPPER LEVEL SHORTWAVE PASSING TO OUR NORTH WILL ACT TO
FLATTEN THE FLOW TO A MORE ZONAL CONFIGURATION BY THIS EVENING AND
THROUGH THE DAY ON SUNDAY. 12Z KTBW SOUNDING PROFILE SHOWED WE
STILL HAVE THE INFLUENCE OF THE RIDGE OVERHEAD WITH A FAIRLY WELL
DEFINED SUBSIDENCE INVERSION SHOWING UP AROUND 800MB. THE
RESULTING CAP IS PRETTY STRONG (AT LEAST OVER THE CENTRAL AND
SOUTHERN ZONES) AND SINCE WE WILL NOT BE SEEING MUCH IN THE WAY OF
HEIGHT FALLS...IT WILL TAKE CONSIDERABLE SURFACE HEATING TO
OVERCOME THIS INHIBITION. THE KJAX SOUNDING STILL SHOWED A BIT OF
A CAP...BUT NOT AS IMPRESSIVE...SO THE INHIBITION DOES WEAKEN
SOMEWHAT TOWARD OUR FAR NORTHERN ZONES.
AT THE SURFACE...
FLOW IS TURNING TO THE SOUTH AND SOUTHWEST AS THE GRADIENT BEGINS
TO TIGHTEN BETWEEN HIGH PRESSURE RIDGING THROUGH THE FLORIDA
STRAITS...AND LOW PRESSURE/WARM FRONTAL FEATURE PASSING WELL TO
OUR NORTH. THE UPPER ENERGY PASSING OVER THE SOUTHEAST CONUS
COMBINED WITH THE LIFT ASSOCIATED WITH THE WARM FRONT IS RESULTING
IN SEVERAL ROUNDS OF STRONG TO SEVERE THUNDERSTORMS ALONG THE
I-10 CORRIDOR OF FLORIDA UP INTO GA. HOWEVER...APPEARS THIS
INCLEMENT WEATHER WILL REMAIN TO THE NORTH OF OUR FORECAST ZONES.
&&
.SHORT TERM...
REST OF TODAY...
SEA BREEZE BOUNDARY PUSHED VERY QUICKLY INLAND TODAY ON THE
STRENGTH OF THE SYNOPTIC SOUTHWESTERLY FLOW. SAW JUST A FEW BRIEF
SHOWERS POP UP ALONG THIS BOUNDARY TO THE SOUTH OF THE I-4
CORRIDOR...BUT THESE ARE NOW EXITING THE FORECAST AREA TOWARD THE
FLORIDA I-95 CORRIDOR. SUBSIDENCE AND THE CAPPING ALOFT WILL
GENERALLY NOW RESULT IN A DRY AND BREEZY REST OF THE AFTERNOON
AND EVENING ACROSS WEST CENTRAL AND SOUTHWEST FLORIDA.
TONIGHT...
MAJORITY OF DIURNAL CONVECTION WILL BE OVER TOWARD THE I-95
CORRIDOR THIS EVENING WITH JUST A SLIGHT CHANCE OF A SHOWER OR
STORM OVER OUR FAR INLAND AREAS...AND THAT THREAT WILL BE ENDING
FAIRLY EARLY. WILL BE A WARM AND HUMID OVERNIGHT PERIOD WITH
STEADY SOUTHWEST FLOW OFF THE GULF OF MEXICO. LATE AT NIGHT WILL
SEE A FRONTAL BOUNDARY SAGGING SOUTHWARD ACROSS AL/GA. THE LOW
LEVEL FLOW AHEAD OF THIS BOUNDARY OVER THE NORTHEAST GULF BETWEEN
1000-850MB BECOMES SLIGHTLY CONVERGENT IN NATURE USING STREAMLINE
ANALYSIS. USUALLY SPEAKING IT DOES NOT TAKE MUCH IN THE WAY OF
FORCING/TRIGGER WITHIN SW FLOW TO GET SOME SHOWERS GOING OVER THE
WATER. THEREFORE WOULD EXPECT THIS LOWER LEVEL FOCUS TO SUPPORT
THE DEVELOPMENT OF A FEW SCT SHOWERS AND PERHAPS A THUNDERSTORM
AFTER MIDNIGHT...THAT WOULD THEN TRANSLATE TOWARD THE NATURE
COAST LATE AT NIGHT. MAY EVEN SEE A FEW SHOWERS AS FAR SOUTH AS
THE TAMPA BAY AREA TOWARD DAWN. WILL HAVE LOW END CHANCE POPS FOR
THE NATURE COAST AND NORTHERN MARINE ZONES...AND A SLIGHT CHANCE
20% POP FURTHER SOUTH TO TAMPA BAY.
SUNDAY...
SURFACE FRONT SETTLES DOWN TOWARD THE I-10 CORRIDOR BY LATE IN THE
DAY. THIS BOUNDARY ALONG WITH SOME SUBTLE UPPER LEVEL SHORTWAVE
ENERGY PASSING THROUGH THE SOUTHEAST CONUS SUGGESTS THE BEST RAIN
CHANCES...IN THE FORM OF SCT SHOWERS / ISOLATED STORMS WILL EXIST
TO THE NORTH OF THE I-4 CORRIDOR. FURTHER SOUTH WHERE THERE WILL
BE LITTLE TO NO SYNOPTIC FORCING FOR LIFT...IT WOULD TAKE THE
SEA-BREEZE TO FORCE CONVECTION...AND EXPECTING THE STRONG
SOUTHWEST FLOW IN THE BL TO PREVENT MUCH OF A DEFINED SEA-BREEZE
FROM FORMING. SO...FORECAST WILL FEATURE CHANCE 30-50% POPS WITH
MOSTLY CLOUDY SKIES NORTH OF THE I-4 CORRIDOR AND SLIGHT CHANCE
20% POPS AND PARTLY CLOUDY FURTHER SOUTH TO AROUND SARASOTA.
FINALLY WILL KEEP RAIN MENTION OUT OF THE FORECAST FOR THE FAR
SOUTH AROUND FORT MYERS. THIS FAR SOUTHERN ZONES WILL HAVE TO WAIT
UNTIL MONDAY...WHEN THE FRONT IS IN CLOSER PROXIMITY...TO SEE
THEIR SHOWER/STORM CHANCES INCREASE.
&&
.LONG TERM (MONDAY THROUGH NEXT SATURDAY)...
AN UPPER LOW INITIALLY NEAR THE FOUR CORNERS AREA TRACKS EAST
THROUGH TUE WITH ZONAL FLOW ALOFT THE GULF REGION...ALLOWING A
FRONTAL BOUNDARY TO MEANDER WEST TO EAST ACROSS FL AND THE
ADJACENT WATERS. BY LATE TUE OR EARLY WED THE UPPER LOW/TROUGH HAS
REACHED THE MISSISSIPPI VALLEY AND SAGGED SOUTH INTO THE GULF...
FORMING A SURFACE LOW IN THE CENTRAL GULF OR GULF COAST. THESE TWO
FEATURES MOVE EAST...WITH A COLD FRONT TRAILING THE SURFACE LOW...
ACROSS THE LOWER EASTERN SEABOARD AND OUT OVER THE ATLANTIC DURING
THU OR EARLY FRI. FOR THE END OF THE PERIOD DEEP LAYER RIDGING
BUILDS IN THE MID CONUS AND BEGINS TO WORK EAST.
THE GLOBAL MODELS CONTINUE IS HAVE DIFFERING SOLUTIONS AND ARE
SUSPECTED OF OVER DOING SOME ELEMENTS. THE ECMWF IS MORE
ROBUST...FASTER...AND WITH A MORE NORTHERLY TRACK THAN THE GFS. IN
ANY CASE THE FORECAST THINKING IS FOR A MOIST TO WET EARLY AND MID
WEEK THEN DRYING OUT GOING TOWARD THE WEEKEND. THE HIGHEST COVERAGE
AND BEST ODDS OF STRONG STORMS AND SOME FLOODING WILL BE TUE INTO
WED. TEMPERATURES NEAR TO ABOVE NORMAL WILL DROP TO NEAR NORMAL BY
THE WEEKEND...THANKS IN PART TO CLOUD COVER...RAINFALL...AND DRIER
COOLER AIR MOVING IN BY THE END OF THE WEEK.
&&
.AVIATION...
SEA BREEZE BOUNDARY HAS PUSHED WELL INLAND LEAVING ALL THE
TERMINALS OF WEST CENTRAL AND SOUTHWEST FLORIDA WITH PREVAILING
VFR CONDITIONS AND LITTLE TO NO CHANCE OF RAIN THE REMAINDER OF
THE DAY. WINDS WILL BE STEADY AND GUSTY AT TIMES FROM THE
SOUTHWEST...WITH THE WINDS BECOME LESS GUSTY AFTER SUNSET. A
BRIEF PERIOD OF MVFR CIGS WILL BE POSSIBLE FOR KSRQ/KPIE/KTPA AND
KLAL EARLY SUNDAY MORNING...HOWEVER POTENTIAL IS LOW ENOUGH AT
THIS POINT TO LEAVE MENTION OUT OF THE CURRENT TAF PACKAGE.
&&
.MARINE...
THE GRADIENT TIGHTENS TODAY ACROSS THE EASTERN GULF OF MEXICO
BETWEEN LOW PRESSURE PASSING TO OUR NORTH AND A RIDGE OF HIGH
PRESSURE THROUGH THE FLORIDA STRAITS. THE GRADIENT WILL BE
TIGHTEST TO THE NORTH OF ENGLEWOOD WHERE CAUTIONARY LEVEL WINDS
ARE EXPECTED TO DEVELOP TONIGHT INTO EARLY SUNDAY MORNING. WINDS
AND SEAS WILL CONTINUE TO FLIRT WITH CAUTIONARY LEVELS THROUGH THE
DAY ON SUNDAY AS A FRONT SLOWLY APPROACHES FROM THE NORTH. THIS
FRONT WILL LIKELY DROP INTO THE NORTHEAST GULF OF MEXICO AND STALL
DURING THE EARLY PORTION OF NEXT WEEK.
&&
.FIRE WEATHER...
SOUTH TO SOUTHWEST WINDS ACROSS WEST CENTRAL AND SOUTHWEST FLORIDA
WILL CONTINUE THROUGH SUNDAY BETWEEN HIGH PRESSURE TO OUR SOUTH AND
A FRONTAL BOUNDARY SINKING SOUTH AND EVENTUALLY STALLING ACROSS
NORTH FLORIDA DURING SUNDAY. WILL SEE AN INCREASING CHANCE OF SHOWERS
AND THUNDERSTORMS ON SUNDAY MAINLY NORTH OF THE I-4 CORRIDOR. AS THIS
FRONT SINKS FURTHER SOUTH INTO THE STATE ON MONDAY...BETTER RAIN
CHANCES WILL ALSO EXPAND SOUTH TO INCLUDE THE REMAINDER OF WEST
CENTRAL AND SOUTHWEST FLORIDA. RELATIVE HUMIDITY VALUES WILL
REMAIN WELL ABOVE CRITICAL LEVELS THROUGH THE EARLY PORTION OF
NEXT WEEK AND OTHER THAN HIGH DISPERSION INDICES SUNDAY
AFTERNOON...NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED.
FOG POTENTIAL...A FEW AREAS OF LATE NIGHT FOG ARE POSSIBLE TONIGHT
AWAY FROM THE IMMEDIATE COAST...HOWEVER NO SIGNIFICANT FOG IS
EXPECTED THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 86 76 83 / 10 30 40 50
FMY 76 90 77 91 / 0 10 10 40
GIF 73 88 73 86 / 0 20 40 50
SRQ 77 84 76 85 / 0 20 40 50
BKV 71 87 70 85 / 20 30 40 50
SPG 77 85 76 83 / 10 20 40 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL
CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA
LONG TERM...09/RUDE
DECISION SUPPORT...09/RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
104 PM CDT SAT APR 25 2015
.UPDATE...
ISSUED AT 1114 AM CDT SAT APR 25 2015
STORM SYSTEM STILL WELL OUT TO THE WEST THIS MORNING AS FIRST
ROUND OF PRECIPITATION SPREAD ACROSS CENTRAL ILLINOIS. A SHORT
BREAK IN THE HEAVIER RAINFALL POSSIBLE, THOUGH SOME SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP, BUT MORE SCATTERED IN
NATURE AS THE LOW TRACKS TOWARDS THE REGION. HRRR AND NAM BOTH
PERSISTENT IN DEVELOPMENT OF SECOND ROUND LATER THIS AFTERNOON
AFTER 18Z. ALTHOUGH THE HEAVIER RAINFALL SEEMS TO BE PROJECTED FOR
SOUTH OF A LINE FROM ROUGHLY SPRINGFIELD TO PARIS...SOME SCATTERED
ACTIVITY NORTH TO THE I-74 CORRIDOR CANNOT BE RULED OUT. SOME
MINOR UPDATES, BUT MAINLY A WET AND SHOWERY AFTERNOON WITH TEMPS
HANGING UP IN THE 50S. BIGGER THREAT FOR POTENTIAL SEVERE
DEVELOPMENT STILL IN THE AFTERNOON HOURS WHEN THE WARM FRONT LIFTS
INTO THE SOUTHERN CWA...BUT THE TREND IN THE MODELS HAS BEEN AN
INCREASINGLY SOUTHERN TRACK FOR THE LOW.
&&
.SHORT TERM...(TODAY)
ISSUED AT 228 AM CDT SAT APR 25 2015
VERTICALLY STACKED SYSTEM CONTINUES TO WEAKEN AS IT MOVES ACROSS THE
PLAINS AND INTO THE MISSISSIPPI VALLEY TODAY. MODELS ARE RELATIVELY
CONSISTENT IN TRACKING THE ASSOCIATED SURFACE LOW JUST SOUTHWEST OF
THE FORECAST AREA ALONG A WARM FRONT THAT IS EXPECTED TO PUSH INTO
SOUTHERN ILLINOIS TODAY. MODELS FROM THE 00Z SUITE CONTINUE TO
REFLECT THAT EVEN OUR SE IL COUNTIES SHOULD REMAIN IN COOL
SECTOR...SUGGESTING THE BIGGEST THREAT WILL BE FROM HAIL AND
POSSIBLY DAMAGING WINDS DEPENDING ON HOW FAR NORTH OF THE WARM FRONT
THE THREATENED AREA DEVELOPS. WILL ALSO HAVE TO WATCH THE PROGRESS
OF THE FRONT AS THERE IS POTENTIAL FOR SUPERCELL DEVELOPMENT ALONG
AND JUST NORTH OF THE BOUNDARY. BULK SHEAR 0-6KM OF 40-50 KTS IS
FORECAST FOR SOUTH OF I-70.
PERIODS OF OVERRUNNING PRECIPITATION WILL PERSIST THROUGH THE DAY
GIVEN OUR POSITION WITH RESPECT TO THE FRONT. BEST LIFT EVIDENT
BETWEEN 12Z AND 16Z. WITH VERY MOIST FLOW ADVECTING INTO THE AREA
(SHV SOUNDING FROM 25/00Z HAD 1.84 IN. OF PRECIPITABLE WATER WHICH
IS NEAR THE RECORD LEVEL FOR THIS TIME OF YEAR) RAINFALL AMOUNTS
WILL LIKELY EXCEED AN INCH THROUGH MOST OF THE FORECAST AREA.
PRECIPITATION AND ABUNDANT CLOUDS SHOULD KEEP TEMPS BELOW NORMAL.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 228 AM CDT SAT APR 25 2015
HAVE LIMITED EVENING THUNDER CHANCES TO THE SOUTHEAST PART OF THE
FORECAST AREA...AS SURFACE LOW SHOULD BE SLIDING ACROSS THE SOUTH
TIP OF THE STATE BY THAT POINT. OTHERWISE...RAIN CHANCES TO QUICKLY
ERODE FROM NORTHWEST TO SOUTHEAST THIS EVENING AS THE LOW PULLS AWAY.
PERSISTENT NORTHEAST FLOW EXPECTED ACROSS THE AREA EARLY NEXT
WEEK...AS AN UPPER LOW SLOWLY MOVES OUT OF THE DESERT SOUTHWEST INTO
THE SOUTHERN PLAINS AND ANOTHER SPINS OVER NEW ENGLAND. SURFACE HIGH
PRESSURE BETWEEN THESE SYSTEMS WILL KEEP THINGS DRY FROM SUNDAY
THROUGH TUESDAY. LONGER RANGE MODELS KEEP THE PRECIPITATION WITH THE
SOUTHERN LOW SOUTH OF OUR AREA THROUGH MID WEEK. HOWEVER, A
SHORTWAVE MOVING THROUGH THE CANADIAN PRAIRIES AND THE NORTH CENTRAL
U.S. WILL BE ENTERING THE MIDWEST BY TUESDAY EVENING. A SMALL PIECE
OF ENERGY MAY CUT OFF IN THIS WAVE...BUT THERE IS NOT GOOD AGREEMENT
IN THE MODELS AS TO WHERE AND HOW STRONG. THE ECMWF IS WETTEST AND
MOST PROGRESSIVE WITH THE WAVE AND PINCHES OFF A LOW IN THE TROUGH
OVER SOUTHERN LAKE MICHIGAN ON WEDNESDAY...WHILE THE GFS AND
CANADIAN MODELS DO THIS ABOUT 18 HOURS EARLIER IN SOUTHWEST
MINNESOTA. ENSEMBLES DO NOT SHOW MUCH AGREEMENT EITHER...SO WILL
KEEP WEDNESDAY DRY AT THIS TIME. THIS FEATURE BASICALLY REPRESENTS
THE BEST CHANCE OF ANY RAIN NEXT WEEK...AS AN UPPER RIDGE BEGINS TO
BUILD ACROSS THE ROCKIES AND INTO THE PLAINS LATE IN THE WEEK. THIS
TREND WILL RESULT IN A GRADUAL WARMING TREND DURING MID TO LATE
WEEK...WITH HIGHS IN THE 70S EXPECTED TO FINALLY RETURN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1251 PM CDT SAT APR 25 2015
CONCERN THROUGH THE NEAR TERM IS THE CONTINUING IFR AND SCATTERED
LIFR CIGS AS THE LOW APPROACHES THE ILX TERMINALS. BRIEF CLEARING
WILL REMAIN POSSIBLE THROUGH PORTIONS OF THE AFTERNOON AS THE
ATMOSPHERE GETS A BIT OF A DIURNAL INFLUENCE...BUT ANY BREAKS WILL
BE BRIEF WITH THE LOW IN SUCH CLOSE PROXIMITY AND CENTRAL ILLINOIS
FIRMLY BACK IN THE COLD AIR. CHANCE FOR SCATTERED THUNDER STILL
POTENTIAL, PARTICULARLY IN THE SOUTHERN TERMINALS AROUND 20Z
THROUGH 00Z. CLEARING FROM WEST TO EAST EXPECTED IN THE OVERNIGHT
HOURS AS THE SYSTEM MOVES OUT OF THE REGION. TOMORROW MORNING
FORECAST ANTICIPATED TO BE MILD...CONCERN STILL REMAINS FOR
POTENTIAL REDUCTION OF VIS WITH THE INCREASED RH IN THE BOUNDARY
LAYER BUT AS IS, THE WINDS SHOULD STAY UP ENOUGH TO COUNTER.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARKER
LONG TERM...GEELHART
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1127 AM CDT SAT APR 25 2015
.UPDATE...
ISSUED AT 1114 AM CDT SAT APR 25 2015
STORM SYSTEM STILL WELL OUT TO THE WEST THIS MORNING AS FIRST
ROUND OF PRECIPITATION SPREAD ACROSS CENTRAL ILLINOIS. A SHORT
BREAK IN THE HEAVIER RAINFALL POSSIBLE, THOUGH SOME SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP, BUT MORE SCATTERED IN
NATURE AS THE LOW TRACKS TOWARDS THE REGION. HRRR AND NAM BOTH
PERSISTENT IN DEVELOPMENT OF SECOND ROUND LATER THIS AFTERNOON
AFTER 18Z. ALTHOUGH THE HEAVIER RAINFALL SEEMS TO BE PROJECTED FOR
SOUTH OF A LINE FROM ROUGHLY SPRINGFIELD TO PARIS...SOME SCATTERED
ACTIVITY NORTH TO THE I-74 CORRIDOR CANNOT BE RULED OUT. SOME
MINOR UPDATES, BUT MAINLY A WET AND SHOWERY AFTERNOON WITH TEMPS
HANGING UP IN THE 50S. BIGGER THREAT FOR POTENTIAL SEVERE
DEVELOPMENT STILL IN THE AFTERNOON HOURS WHEN THE WARM FRONT LIFTS
INTO THE SOUTHERN CWA...BUT THE TREND IN THE MODELS HAS BEEN AN
INCREASINGLY SOUTHERN TRACK FOR THE LOW.
&&
.SHORT TERM...(TODAY)
ISSUED AT 228 AM CDT SAT APR 25 2015
VERTICALLY STACKED SYSTEM CONTINUES TO WEAKEN AS IT MOVES ACROSS THE
PLAINS AND INTO THE MISSISSIPPI VALLEY TODAY. MODELS ARE RELATIVELY
CONSISTENT IN TRACKING THE ASSOCIATED SURFACE LOW JUST SOUTHWEST OF
THE FORECAST AREA ALONG A WARM FRONT THAT IS EXPECTED TO PUSH INTO
SOUTHERN ILLINOIS TODAY. MODELS FROM THE 00Z SUITE CONTINUE TO
REFLECT THAT EVEN OUR SE IL COUNTIES SHOULD REMAIN IN COOL
SECTOR...SUGGESTING THE BIGGEST THREAT WILL BE FROM HAIL AND
POSSIBLY DAMAGING WINDS DEPENDING ON HOW FAR NORTH OF THE WARM FRONT
THE THREATENED AREA DEVELOPS. WILL ALSO HAVE TO WATCH THE PROGRESS
OF THE FRONT AS THERE IS POTENTIAL FOR SUPERCELL DEVELOPMENT ALONG
AND JUST NORTH OF THE BOUNDARY. BULK SHEAR 0-6KM OF 40-50 KTS IS
FORECAST FOR SOUTH OF I-70.
PERIODS OF OVERRUNNING PRECIPITATION WILL PERSIST THROUGH THE DAY
GIVEN OUR POSITION WITH RESPECT TO THE FRONT. BEST LIFT EVIDENT
BETWEEN 12Z AND 16Z. WITH VERY MOIST FLOW ADVECTING INTO THE AREA
(SHV SOUNDING FROM 25/00Z HAD 1.84 IN. OF PRECIPITABLE WATER WHICH
IS NEAR THE RECORD LEVEL FOR THIS TIME OF YEAR) RAINFALL AMOUNTS
WILL LIKELY EXCEED AN INCH THROUGH MOST OF THE FORECAST AREA.
PRECIPITATION AND ABUNDANT CLOUDS SHOULD KEEP TEMPS BELOW NORMAL.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 228 AM CDT SAT APR 25 2015
HAVE LIMITED EVENING THUNDER CHANCES TO THE SOUTHEAST PART OF THE
FORECAST AREA...AS SURFACE LOW SHOULD BE SLIDING ACROSS THE SOUTH
TIP OF THE STATE BY THAT POINT. OTHERWISE...RAIN CHANCES TO QUICKLY
ERODE FROM NORTHWEST TO SOUTHEAST THIS EVENING AS THE LOW PULLS AWAY.
PERSISTENT NORTHEAST FLOW EXPECTED ACROSS THE AREA EARLY NEXT
WEEK...AS AN UPPER LOW SLOWLY MOVES OUT OF THE DESERT SOUTHWEST INTO
THE SOUTHERN PLAINS AND ANOTHER SPINS OVER NEW ENGLAND. SURFACE HIGH
PRESSURE BETWEEN THESE SYSTEMS WILL KEEP THINGS DRY FROM SUNDAY
THROUGH TUESDAY. LONGER RANGE MODELS KEEP THE PRECIPITATION WITH THE
SOUTHERN LOW SOUTH OF OUR AREA THROUGH MID WEEK. HOWEVER, A
SHORTWAVE MOVING THROUGH THE CANADIAN PRAIRIES AND THE NORTH CENTRAL
U.S. WILL BE ENTERING THE MIDWEST BY TUESDAY EVENING. A SMALL PIECE
OF ENERGY MAY CUT OFF IN THIS WAVE...BUT THERE IS NOT GOOD AGREEMENT
IN THE MODELS AS TO WHERE AND HOW STRONG. THE ECMWF IS WETTEST AND
MOST PROGRESSIVE WITH THE WAVE AND PINCHES OFF A LOW IN THE TROUGH
OVER SOUTHERN LAKE MICHIGAN ON WEDNESDAY...WHILE THE GFS AND
CANADIAN MODELS DO THIS ABOUT 18 HOURS EARLIER IN SOUTHWEST
MINNESOTA. ENSEMBLES DO NOT SHOW MUCH AGREEMENT EITHER...SO WILL
KEEP WEDNESDAY DRY AT THIS TIME. THIS FEATURE BASICALLY REPRESENTS
THE BEST CHANCE OF ANY RAIN NEXT WEEK...AS AN UPPER RIDGE BEGINS TO
BUILD ACROSS THE ROCKIES AND INTO THE PLAINS LATE IN THE WEEK. THIS
TREND WILL RESULT IN A GRADUAL WARMING TREND DURING MID TO LATE
WEEK...WITH HIGHS IN THE 70S EXPECTED TO FINALLY RETURN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 605 AM CDT SAT APR 25 2015
SCATTERED HEAVIER PRECIP OVER WESTERN ILLINOIS IS EXPECTED TO
FILL IN OVER THE NEXT FEW HOURS AS STRONG DYNAMICS ASSOCIATED WITH
LEFT EXIT REGION OF JET STREAK OVER THE ARKLATEX REGION. NAM TIME
HEIGHTS INDICATE STRONG DEEP LIFT FOR A PERIOD THIS MORNING WHICH
SHOULD INCREASE RAINFALL RATES AND PLAY HAVOC WITH CIGS. WILL KEEP
PREDOMINATE CIGS MVFR FOR NOW. AS THE WARM FRONT SOUTHWEST OF THE
TERMINALS BEGINS TO SURGE NORTH MAY HAVE LOWERING CIGS THIS
AFTERNOON FOLLOWING THE MAIN PRECIP AREA. WILL TRY TO TREND THIS
POSSIBILITY WITH SO MUCH UNCERTIANTY BY KEEPING MVFR CIGS AND
VSBYS IN PLACE THOUGH THERE COULD BE SPOTS WHERE IFR CIGS WILL BE
POSSIBLE. ONCE THE MAIN WAVE PUSHES EAST OF THE AREA OVERNIGHT MAY
BE SOME PARTIAL CLEARING. NORTHEAST WINDS ARE EXPECTED TO BE
SIGNIFICANT ENOUGH TONIGHT TO LIMIT ANY BR VSBY DROPS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARKER
LONG TERM...GEELHART
AVIATION...BARKER
AREA FORECAST DISCUSSION
NWS JACKSON KY
229 PM EDT SAT APR 25 2015
.UPDATE...
ISSUED AT 230 PM EDT SAT APR 25 2015
ISSUED AN UPDATE TO FURTHER ADJUST THE POPS AND SKY COVER BASED
ON CURRENT TRENDS. WENT A BIT SLOWER ON ERODING CLOUDS IN THE
SOUTH WITH THE NORTH REMAINING WITH CLOUDS BUT THIS WILL CREATE A
HEATING DIFFERENTIAL BOUNDARY BETWEEN NORTHERN AND SOUTHERN
PORTIONS. WITH THIS...EXPECTING SEVERE CONVECTION TO MOVE INTO THE
AREA AFTER 21Z AND MOST LIKELY FROM THE WEST. IT IS UNLIKELY THAT
LIKE THE HRRR SUGGESTS THAT THE STORMS WILL DEVELOP OVER EASTERN
KENTUCKY. HAVE UPDATED THE POPS TO SUGGEST THIS. WILL STILL KEEP
THE TEMPERATURE DIFFERENCES IN PLACE AS WELL. AT THIS
TIME...WARMING CONTINUES IN THE SOUTH AND CONVECTION IN WESTERN KY
IS NEAR OR BEGINNING CONVECTIVE INITIATION. WITH THIS
DEVELOPMENT...WOULD EXPECT THIS ACTIVITY TO MOVE EAST WITH THE
BEST ENVIRONMENT CONVERGING OVER THE HAL ROGERS PARKWAY AND SOUTH.
A NEW ZFP HAS BEEN SENT OUT AND NEW GRIDS HAVE BEEN SENT.
UPDATE ISSUED AT 1130 AM EDT SAT APR 25 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE A SWATH OF SHOWERS
MOVING THROUGH TO THE NORTHEAST ACROSS EASTERN KENTUCKY. AT THIS
TIME...THE WARM FRONT IS DEVELOPING AND SLOWLY MOVING NORTH AND IS
POSITIONED JUST NORTH ALONG THE KY/TN BORDER. CLOUD COVER AT THIS
TIME IS QUITE EXTENSIVE ACROSS THE AREA...THOUGH...SOME PEAKS OF
CLEARING ARE OCCURRING TO THE WEST AND A FEW PEAKS TO THE SOUTH.
HOWEVER...ONGOING CONVECTION ALONG THE GULF COAST SEEMS TO BE
KEEPING CLOUD COVER STREAMING NORTHWARD INTO THE AREA THIS
AFTERNOON. HAVE TIMED A BIT OF CLEARING TO OCCUR OVER SOUTHEAST
KENTUCKY BUT IF THE CLOUD COVER MOVING UP FROM THE SOUTH
CONTINUES...SEVERE CONVECTION WILL BE DRASTICALLY LIMITED INTO
THIS AFTERNOON AND EVENING. LATER THIS EVENING...THE HRRR HINTS AT
AN MCS DEVELOPMENT AND MOVING SOUTH SOUTHEAST INTO THE AREA ALONG
WITH THE SURFACE LOW BY 00Z TONIGHT. AT THIS TIME...THE EVENT MAY
BE TRANSITIONING INTO A HYDRO EVENT. HAVE UPDATED THE ZFP TO TIME
THE THREAT OF SEVERE WEATHER THIS EVENING AND THE PROGRESSION OF
THE WARM FRONT THROUGH THE DAY. IT GOES WITHOUT SAYING THAT THE
NEXT FEW HOURS WILL SAY ALOT ABOUT WHAT TRANSPIRES LATER THIS
AFTERNOON AND INTO THE EVENING.
UPDATE ISSUED AT 13 AM EDT SAT APR 25 2015
BLENDED EARLY MORNING OBS INTO THE FORECAST. NO SUBSTANTIAL
CHANGES WERE MADE.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 411 AM EDT SAT APR 25 2015
AN ACTIVE PERIOD IS IN STORE...WITH EVENTS JUST BEGINNING TO
UNFOLD. AN AREA OF SHOWERS IS EXPECTED TO DEVELOP AND MOVE NE OVER
THE REGION THIS MORNING. HOWEVER...IT IS BEHIND SCHEDULE AS BASED
ON THE 00Z MODELS...WITH A CONVECTIVE SYSTEM OVER MS AND AL
POSSIBLY FOILING THE OUTCOME. THE LATEST HRRR MODEL SUGGESTS IT
WILL STILL HAPPEN...BUT MAY BE MORE FOCUSED ON OUR NORTHERN
COUNTIES.
ONCE THIS PASSES...IT WILL BE A WAITING GAME FOR ADDITIONAL
CONVECTION TO DEVELOP DURING THE AFTERNOON AND EVENING AS A STORM
SYSTEM APPROACHES FROM THE WEST...ALONG A FRONTAL BOUNDARY DRAPED
ACROSS OUR AREA. IT STILL APPEARS THERE WILL BE LARGE SURFACE
BASED INSTABILITY PRESENT IN OUR SOUTHWEST COUNTIES...WITH WEAKER
AND MORE ELEVATED INSTABILITY FURTHER NORTHEAST. SHEAR WILL BE
MORE THAN SUFFICIENT TO SUPPORT ORGANIZED CONVECTION. DRY MID
LEVEL AIR IS ALSO EXPECTED IN OUR SW. THIS WILL PRESENT A THREAT
OF SEVERE WEATHER OVER OUR SW...WITH SUPER CELLS POSSIBLY
PRODUCING LARGE HAIL AND HIGH WINDS...AND A SECONDARY THREAT OF
TORNADOES. EXCESSIVE RAINFALL IS ALSO A CONCERN WITH TRAINING OF
CELLS ALONG THE FRONTAL BOUNDARY. WHERE THIS MAY SET UP IS STILL
UNCERTAIN. ANY HYDRO PROBLEMS LIKELY WOULD NOT ARISE UNTIL THIS
EVENING...AND HAVE OPTED TO LET DAY SHIFT EXAMINE THE 12Z RUN
BEFORE MAKING A DECISION ON A FFA.
THE FRONTAL BOUNDARY WILL MOVE TO OUR SOUTH AS LOW PRESSURE MOVES
EAST THROUGH THE REGION TONIGHT. ANY LINGERING SHOWERS WILL END ON
SUNDAY MORNING AND CLOUDS WILL BREAK UP DURING THE DAY FROM NW TO
SE AS DRY AIR MOVES IN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 AM EDT SAT APR 25 2015
THE MODELS WERE IN GOOD AGREEMENT IN THE EXTENDED. THE PERIOD IS
SET TO BEGIN WITH A LARGE RIDGE OF HIGH PRESSURE MOVE OUT OF THE
NORTH CENTRAL PLAINS AND ACROSS THE LOWER GREAT LAKES AND OHIO AND
TENNESSEE VALLEY REGIONS SUNDAY NIGHT THROUGH TUESDAY. THE PATTERN
IS THEN FORECAST TO CHANGE TUESDAY NIGHT AND WEDNESDAY...AS BOTH
NORTHERN AND SOUTHERN STREAM WEATHER SYSTEMS MAKE THEIR WAY ACROSS
THE GREAT LAKES AND GULF COAST REGIONS. THE SOUTHERN STREAM SYSTEM
APPEARS TO BE THE STRONGER OF THE TWO...AND THEREFORE WOULD HAVE
TO GREATER INFLUENCE ON AREA WEATHER MID WEEK. AS IT STANDS...A
ROUGHLY 60 40 BLEND OF THE ECMWF AND GFS MODELS WAS USED TO CREATE
THE FORECAST FROM TUESDAY NIGHT ONWARD. THE SOUTHERN STREAM
TROUGH IS PROGGED TO BRING MOISTURE OFF THE GULF OF MEXICO
NORTHWARD INTO CENTRAL AND EASTERN KENTUCKY WEDNESDAY AND
WEDNESDAY NIGHT. AS THIS OCCURS...THE NORTHERN STREAM SYSTEM IS
FORECAST TO DIVE SOUTHWARD AND PHASE WITH THE TENNESSEE VALLEY
SOUTHEASTERN CONUS LOW. THE GFS DOES DIFFER SLIGHTLY FROM THE
ECMWF MODEL DURING THIS PERIOD...AS ITS NORTHERN STREAM LOW PUSHES
ON EASTWARD INTO NEW ENGLAND...AS OPPOSED TO PHASING WITH THE
SOUTHERN SYSTEM...AS THE ECMWF IS DEPICTING. THAT BEING
SAID...THIS IS WHERE THE USUALLY MORE CONSISTENT ECMWF MODEL
SOLUTION WAS FAVORED. THERE WILL BE A CHANCE OF RAIN IN THE
FORECAST FOR THE ENTIRE AREA FROM LATE TUESDAY NIGHT THROUGH
THURSDAY NIGHT. HOWEVER...DUE TO THE DIFFERING MODEL
SOLUTIONS...DECIDED TO STAY WITH SLIGHT CHANCE TO CHANCE
POPS...WITH 40 BEING THE HIGH END DURING THE WET PERIOD. FRIDAY
AND FRIDAY NIGHT LOOK TO BE DRY AS THE SOUTHERN STREAM WEATHER
SYSTEM EXITS TO OUR EAST AND ANOTHER RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE SOUTHERN AND SOUTHEASTERN CONUS.
TEMPERATURES NEXT WEEK WILL LIKELY BE BELOW NORMAL THROUGH
THURSDAY...DUE TO THE INFLUENCE OF CLOUD COVER AND PRECIPITATION
AND THE FACT THAT THIS WEEKENDS TEMPERATURES WILL ALSO REMAIN WELL
BELOW NORMAL DUE WIDESPREAD CLOUD COVER AND PRECIPITATION. WHAT
THIS AMOUNTS TO IS THE ATMOSPHERE WILL STARTING OFF BEHIND THE
EIGHT BALL TO START THE WEEK TEMPERATURE WISE...MAKING IT
DIFFICULT FOR THINGS TO WARM UP AS MUCH AS NORMAL DUE TO THE SHORT
BREAK BETWEEN WEATHER SYSTEMS. HIGHS ON FRIDAY SHOULD BE RIGHT
AROUND NORMAL ACROSS THE ENTIRE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 230 PM EDT SAT APR 25 2015
THE SHOWERS THAT HAVE MOVED THROUGH THE NORTHERN HALF OF EASTERN
KENTUCKY THIS MORNING HAS MOVED NORTHEAST OUT OF THE AREA BUT IFR
AND BELOW CIGS AND VIS REMAIN AND HAVE INCLUDED THIS IN THE TAFS
THROUGH THE EVENING HOURS. AS WARM FRONT SLOWLY NUDGES
NORTH...CLOUDS WILL BE ON THE INCREASE IN THE SOUTH AS
THUNDERSTORMS DEVELOP AND MOVE IN FROM THE NORTHWEST. THIS WILL
RESULT IN BELOW FEILD MINS THROUGH THE NIGHT WITH THUNDER NEAR
EACH STATION THROUGH 06Z. AFTERWARD...LOW CIGS AND VIS WILL LINGER
THROUGH THE MORNING HOURS. WINDS WILL REMAIN RELATIVELY LIGHT
THROUGH THE PERIOD OUTSIDE OF THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...HAL
LONG TERM...AR
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
109 PM EDT Sat Apr 25 2015
...Updated Aviation Discussion...
...Forecast Update...
Updated 930 AM EDT Sat Apr 25 2015
Latest guidance including the latest SPC Day 1 Outlook continues to
trend the severe threat slightly to the north. No big changes have
been made to the grids, but have tried to trend the pop forecast a
bit towards the latest hi-res model guidance. Also nudged the area
where severe storms are mentioned slightly further to the north. The
ongoing precipitation has not had any lightning associated with it
so far. However, think we could still see some isolated flashes
through the late morning hours.
Updated 621 AM EDT Sat Apr 25 2015
No major changes needed to the forecast this morning, as it is
largely on track. Still expecting rain showers to continue to
blossom over the region, especially along and north of I-64 this
morning. This is all in response to a low-level jet and isentropic
ascent veering into the region. May see a few rumbles of thunder
especially as we get into the late morning hours, but no severe
weather is expected through noon.
The 06Z NAM has come in further north with the warm frontal
placement late this afternoon, which would bring the I-64 corridor
more into play for severe potential. However, the latest runs of
the HRRR continue to show the warm front stalling south of I-64 and
very close to the current forecast position. Given the HRRR has a
decent handle on ongoing convection, and the support of the other
hi-res guidance in regards to expected frontal position this
afternoon, see no need to adjust things further north based on the
06Z NAM quite yet. Will continue to monitor trends through the
morning hours and especially the 12Z guidance suite.
.SHORT TERM (Now through Saturday Night)...
Issued at 345 AM EDT Sat Apr 25 2015
...Severe Weather Likely This Afternoon and Evening...
Overview
========
The current synoptic setup features a split-flow regime across the
CONUS. The Ohio Valley will be affected by a PV anomaly currently
across eastern Kansas and western MO, which will push through the
region late this afternoon into tonight.
In response to the ejecting PV anomaly out of the southwest flow
aloft, a surface low has formed across portions of eastern KS. This
low will slide east today, but will begin to fill as the overall
system encounters confluent flow over the Ohio Valley. A very sharp
warm front associated with this low pressure system will develop
across the Ohio Valley today.
This Morning
============
With the ejecting wave, isentropic ascent has increased across the
region this morning. This has led to showers breaking out across
the Ohio Valley, and the radar should continue to blossom through
the morning hours as a low-level jet of 40-50 knots veers into the
region towards sunrise. Forecast soundings show limited elevated
instability, so severe weather is not expected. Just some showers
with a few embedded rumbles of thunder appears likely.
This Afternoon/Evening
======================
The placement of the aforementioned sharp warm front will be
absolutely critical to how far north the severe weather threat gets
this afternoon/evening. The 25/00Z guidance shifted this front
south just a bit from previous runs, which would take much of the
I-64 corridor out of the main severe risk. Will cautiously trend
the forecast towards this more southern solution given the support
on almost guidance members, but still am a bit weary this front
could end up surging further north, especially if there is less
showers/storm coverage this morning than expected (less convective
enhancement to the front). This warm front will be the main player
that we will continue to monitor through the day.
At this point, expect the front to align itself roughly along a line
from Owensboro, to north of Elizabethtown, over towards Lebanon
by late this afternoon. To the south of it, a warm and unstable
airmass is likely to materialize given temperatures rising to near
80 and dewpoints in the middle 60s. This low-level environment
coupled with very steep lapse rates aloft will support MLCAPEs
anywhere from 1500-3000 J/kg, with much of that CAPE residing within
the hail growth zone (-10 to -30C).
The evolution of the convection could be rather complex. There
seems to be a decent signal in the hi-res guidance that the strong
warm front may lead to convective initiation, which will likely be
initially discrete in nature. Given 0-6km shear well over 50 knots,
these will be supercellular, if they are to form. The aforementioned
instability coupled with deep-layer shear will lead to a large hail
threat, with golf ball to even baseball-sized hail not out of the
question in some of these storms. Bunker`s RM storm motion vectors
place the motion of these potential supercells almost parallel to
the warm front, which is worrisome because any storm that forms
along this front will have access to enhanced helicity, given the
backed surface winds. Therefore, think there is an enhanced tornado
threat right along this boundary wherever it happens to set up,
perhaps more of a threat than SPC is currently highlighting with
their 5% Tornado risk.
Further south (across far southern KY, near TN border), strong
mixing coupled with the fact that the surface low will be filling
will lead to more veered surface winds, which should cut down
somewhere on the effective SRH. However, with westerly low-level
jet expected to strengthen towards 26/00Z, hodographs will be
long/curved enough to support an isolated tornado threat early this
evening in areas south of the warm front. Coverage of these storms
not tied to the warm front will likely be rather isolated, given a
lack of convergence and the presence of a weak cap in the warm
sector.
By a bit later this evening, the actual surface low will push into
west-central KY. Near the triple point of this low, enhanced
convergence will likely lead to a more concentrated area of
convection, perhaps a mix of bowing segments and supercells which
will push into the I-65 corridor toward 02-04Z. By this time,
daytime instability should be beginning to wane, but still think
this second round will carry a severe threat of large hail, damaging
winds, and isolated tornadoes as it pushes southeast across
south-central KY.
Bust Potential
==============
There remains some potential bust factors with this setup. The
first and most obvious, is the morning convection. We will need
this to clear out and some sunshine to break out south of the warm
front this afternoon for us to destabilize. Given the general
guidance agreement, do have pretty high confidence this will occur
and we will become quite unstable across southern KY late this
afternoon.
The other potential bust factor will if discrete development will
occur late this afternoon/early evening. Warm fronts can be tricky
in initiating surface-based convection, so we could go through the
day not seeing much becoming sustained along the front. In
addition, the weak cap could hold through the rest of the warm
sector giving very little coverage of discrete convection until the
more concentrated line of storms approaches with the surface low
well after peak heating.
Summary
=======
While there is bust potential, have fairly high confidence in severe
weather this afternoon and evening. Think the main threats will be
hail and damaging winds, but an enhanced tornado threat will be
found right along the warm front. This is something we will
continue to monitor closely this afternoon. Even north of the warm
front in Lexington and Louisville, forecast soundings show quite a
bit of elevated instability above the stable boundary layer, so
severe hail will certainly be a possibility even in areas north of
the warm front.
.LONG TERM (Sunday through Friday)...
Issued at 300 PM EDT Sat Apr 25 2015
Overall tranquil weather pattern expected for much of the extended
forecast period. Average flow aloft pattern will be somewhat blocky
and amplified with troughs over the northeastern and western U.S.
and ridging in the central U.S. However, an mid-level low will
meander east over the southern Plains to the south of the ridge.
Models suggest that this system will move east into the Gulf Coast
states and weaken mid to late next week, and not phase with a
northern stream shortwave rotating southeast over the upper Ohio
Valley. As a result, dry weather should prevail through the period.
With cool surface high pressure to the north of our area early in
the week, temperatures will be below normal with highs in the upper
50s to mid 60s Monday afternoon, low-mid 60s Tuesday, and mid-upper
60s Wednesday. Expect lows in the lower 40s in many areas Tuesday
morning (possibly upper 30s in valleys), and 40s Wednesday morning.
For late week into next weekend, the ridge aloft should slide east
resulting in continued dry weather and a moderating trend, with
afternoon highs expected in the 70s Friday and Saturday.
&&
.AVIATION (18Z TAF Update)...
Updated at 107 PM EDT Sat Apr 25 2015
Ceilings lowered to IFR at SDF and LEX this morning as they
remain north of the warm front. This front should stay to the south
of both these terminals. Therefore do not see much improvement in
ceilings, except for perhaps a few hours late this afternoon when
storms are expected to develop. These storms will be hit and miss,
but any that do develop could produce hail. The storms will weaken
after sunset with some showers lingering into the overnight hours in
the wake of a low pressure system crossing the area. IFR ceilings
are expected to persist through much of the night, beginning to lift
around dawn. Winds will shift to northerly to northeasterly as the
low moves through.
BWG is south of the warm front. Ceilings through the afternoon will
likely bounce back and forth between MVFR and VFR as clouds scatter
out from time to time. Strong to possibly severe storms will develop
late this afternoon in the vicinity of BWG. These will move out by
mid to late evening as a cold front moves through. IFR ceilings are
expected to develop in the wake of the front and persist into the
morning hours tomorrow.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........EER/KJD
Short Term.....KJD
Long Term......RAS
Aviation.......EER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1220 PM CDT SAT APR 25 2015
.DISCUSSION...
FOR THE 18Z TAF PACKAGE.
&&
.AVIATION...THUNDERSTORM ACTIVITY IS BEGINNING TO DECREASE AND SHIFT
EAST OF THE AREA...BUT ADDITIONAL CONVECTION IS DEVELOPING OVER THE
MID TEXAS COAST. FOR NOW...BELIEVE THIS WILL MOVE OVER THE WATERS.
LATEST HRRR KEEPS SCATTERED PRECIPITATION OVER LOWER ACADIANA
THROUGH MOST OF AFTERNOON WITH LESS COVERAGE ELSEWHERE. FOR
ARA...WILL HAVE TEMPO THUNDERSTORM ACTIVITY THROUGH MID
AFTERNOON. OTHERWISE WILL HAVE VCTS FOR THE REMAINING SITES.
MOISTURE PROFILE IS CONDUCIVE FOR LOW CLOUDS AND FOG FOR TONIGHT.
WILL KEEP MOST CIGS AND VSBYS IN THE MVFR RANGE. VFR CONDITIONS
ARE FORECASTED BY MID MORNING.
&&
PREV DISCUSSION... /ISSUED 547 AM CDT SAT APR 25 2015/
SYNOPSIS...
LATEST UA ANALYSIS AND WATER VAPOR IMAGERY SHOWS AN UPR LOW OVER
KS...WITH A SHORTWAVE TROF EXTENDING SOUTH ACRS OK AND TX. AMPLE
MOISTURE CONTINUES TO STREAM ACRS THE REGION ON SWLY FLOW ALOFT.
LATEST RADAR MOSAIC SHOWS TWO MAIN CLUSTERS OF CONVECTION...A
COUPLE OF BANDS OF SHOWERS AND TSTMS EXITING THE LOWER MS VALLEY
AND ANOTHER AREA OF STORMS UPSTREAM ACRS THE HILL COUNTRY IN TX.
THIS IS THE NEXT SYSTEM TO MOVE INTO THE AREA...AND WILL BEAR
WATCHING THROUGH THE MORNING AND EARLY AFTN.
DISCUSSION...
LATEST HRRR RUNS SHOW THE CLUSTER OF STORMS ACRS TX MOVING INTO
OUR AREA LIKELY AROUND 9 OR 10 AM THIS MORNING. THIS ACTIVITY WILL
CROSS THE AREA EARLY TODAY...WITH MOST OF THE CONVECTION EXPECTED
TO BE CONCENTRATED ACRS SRN PORTIONS OF THE AREA. IT IS FCST TO
EVENTUALLY EXIT THE OUR S CNTL LA ZONES BETWEEN 1 AND 3 PM. PLENTY
OF MOISTURE IS AVAILABLE WITH PW VALUES RUNNING CLOSE TO 1.8
INCHES...AND LIFT WILL BE HELPED BY THE PRESENCE OF A ROBUST RIGHT
ENTRANCE REGION BENEATH THE UPPER JET. AS A RESULT...SOME STORMS
WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL ALONG WITH A
FEW STRONG STORMS AMIDST MODT LOW LVL SHEAR.
RAIN CHCS WILL GRADUALLY DIMINISH THROUGH THE AFTN AS THE MAIN
ENERGY WITH THE DISTURBANCE MOVES OFF TO THE EAST. A BRIEF BREAK
FROM THE SHOWERS AND TSTMS ARRIVES TONIGHT INTO SUNDAY AS SLIGHTLY
DRIER AIR ALOFT MOVES INTO THE REGION. HOWEVER...THE NEXT
DISTURBANCE UPSTREAM WILL BEGIN TAKING SHAPE AS AN UPR LOW DIVES
SE ACRS THE INTERMOUNTAIN WEST SUNDAY. THIS LOW WILL EJECT INTO
THE SRN PLAINS MONDAY...WITH A MOIST AND DIVERGENT SWLY FLOW
BECOMING RE-ESTABLISHED OVER THE AREA. SFC CYCLOGENESIS WILL ALSO
DEVELOP OVER TX ON MONDAY...WITH A MIDLVL JET TRANSLATING EAST
TOWARD ERN TX. EXPECT SHOWERS AND TSTMS TO DEVELOP OVER TX SUNDAY
NIGHT...THEN SPREAD EAST ACRS THE AREA MONDAY. INSTABILITY WILL
INCREASE ON MONDAY WITH WIND PROFILES SHOWING STRONG VEERING WITH
HEIGHT AND HELICITY VALUES EXCEEDING 200 M2/S2. SPC HAS THE
REGION HIGHLIGHTED IN A SLT RISK FOR SVR STORMS WITH LARGE
HAIL...STRONG WINDS AND EVEN A FEW TORNADOES POSSIBLE. IN
ADDITION...STORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS. LIKELY POPS REMAIN OVER THE AREA MONDAY NIGHT...THEN
GRADUALLY DIMINISH FROM WEST TO EAST TUESDAY AS THE SYSTEM SHIFTS
EAST OVER THE LOWER MS VALLEY.
MEANWHILE...THE SFC LOW OVER TX WILL MOVE EAST NR THE COAST MONDAY
NIGHT INTO TUESDAY. NLY FLOW WILL DEVELOP BEHIND THE SFC
LOW...WITH DRIER NWLY FLOW DEVELOPING ALOFT. THIS WILL FINALLY
BRING AN END TO THE RAIN...WITH DRIER...COOLER AND MORE
COMFORTABLE CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE WEEK.
OVERNIGHT LOWS WEDNESDAY AND THURSDAY MORNING ARE EXPECTED TO FALL
INTO THE 50S...COOLER THAN NORMAL FOR THIS TIME OF YEAR...WHILE
HIGHS WILL BE IN THE 70S. THE DRY WEATHER WILL CONTINUE INTO THE
WEEKEND WITH A GRADUAL WARMING TREND DEVELOPING.
24
MARINE...
A MDT SLY FLOW WILL CONTINUE THROUGH MONDAY WITH HIGH PRES
EAST OF THE REGION AND A SERIES OF LOW PRES SYSTEMS DEVELOPING WEST
OF THE AREA. AN UPR LVL DISTURBANCE MOVING THROUGH THE REGION WILL
KEEP A CHC FOR SHOWERS AND STORMS TODAY. ANOTHER DISTURBANCE WILL
MOVE INTO THE AREA ON MONDAY...BRINGING ANOTHER CHC FOR SHOWERS
AND TSTMS. AS THIS DISTURBANCE CROSSES THE AREA...IT WILL INDUCE
SFC LOW PRES OVER TX. THIS LOW WILL THEN CROSS THE COASTAL WATERS
MONDAY NIGHT...WITH A TRAILING COLD FRONT MOVING THROUGH ON
TUESDAY. SOME OF THE STORMS WITH THIS SYSTEM COULD BE
STRONG...CAPABLE OF PRODUCING GUSTY WINDS AND FREQUENT CLOUD TO
WATER LIGHTNING. ONCE THE FRONT PASSES THROUGH THE AREA...RAIN
CHCS WILL COME TO AN END...WITH MODT TO STRONG NLY WINDS
DEVELOPING POSSIBLY BRINGING SMALL CRAFT ADVISORY CONDITIONS TO
THE WATERS TUESDAY NIGHT INTO WEDNESDAY.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 67 89 66 79 / 10 20 20 60
LCH 70 85 70 81 / 10 20 20 60
LFT 69 88 69 82 / 10 20 20 60
BPT 69 85 70 81 / 10 20 20 60
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...04
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
313 PM EDT SAT APR 25 2015
.SYNOPSIS...
LOW PRESSURE OVER KENTUCKY WILL TRACK EAST THIS AFTERNOON AND
THEN MOVE SOUTHEAST ACROSS THE CAROLINAS TONIGHT AND OFF THE COAST
SUNDAY MORNING. THE LOW REMAINS OFFSHORE AS HIGH PRESSURE
GRADUALLY BUILDS IN FROM THE WEST FOR THE FIRST HALF OF THE WEEK.
ANOTHER LOW MAY IMPACT THE REGION FOR THE LATTER HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
FOR REST OF THIS AFTERNOON...AT 1830Z RADAR SHOWING SOME SCATTERED
RETURNS OVER LOWER SRN MD...BUT THE REMAINDER OF THE CWA WAS
CLOUDY BUT PRECIP FREE MOSTLY. LEADING EDGE OF PRECIP ALONG AN
ELKINS-STAUNTON VA-CHARLOTTESVILLE LINE. THIS AREA IS MOVING EAST
AT A PRETTY GOOD CLIP...AND WILL OVERSPREAD THE REGION IN THE NEXT
2-4 HOURS...EXCEPT NE MD COULD TAKE UNTIL 7-8PM FOR PRECIP TO START.
LOW LEVELS STILL QUITE DRY ACROSS NRN 2/3RDS OF CWA. PRECIP
REACHING SURFACE WILL CREATE LOW LEVEL COOLING...SO TEMPS WILL
KEEP ON THE COOL SIDE REMAINDER OF THIS AFTERNOON ESPECIALLY FOR
THIS LATE IN APRIL.
FOR TONIGHT...PRECIP ASSOCIATED WITH WARM FRONTAL SYSTEM LIFTING
ACROSS THE REGION WILL IMPACT THE REGION MAINLY THROUGH 06Z...THEN
MODELS SUGGEST BULK OF PRECIP WILL LIGHTEN CONSIDERABLY AFTER
THEN. EARLIER TIMING OF PRECIP SUGGESTED LINGERING LIGHT PRECIP
WOULD IMPACT ENTIRE CWA THROUGH 10-12Z SUNDAY MORNING. BUT
GUIDANCE TODAY SUGGESTS A FASTER TIMING WHICH IS REFLECTED IN THE
FORECAST. TEMPERATURES WILL NOT FALL MUCH OVERNIGHT AND BASICALLY
TRENDED MIN TEMPS TO ADJUSTED MET GUIDANCE.
FORECAST RAINFALL AMOUNTS GENERALLY LINE UP PRETTY WELL WITH WPC
QPF AMOUNTS AND WILL BE GENERALLY HEAVIER ACROSS THE SW PORTION
WITH AMOUNTS AROUND ONE HALF INCH...DC METRO AROUND ONE- QUARTER
OF AN INCH...BALTIMORE BETWEEN 1-2 TENTHS.
HI RES CAM MODELS SHOW GOOD AGREEMENT WITH 12Z NAM/GFS/SREF ON
TIMING OF PRECIP ACROSS AREA. LATEST HRRR GUIDANCE SUGGEST THE
PRECIP COULD EVEN BE MORE SCATTERED IN COVERAGE THIS EVENING.
FOR SUNDAY...THERE COULD BE LINGERING LIGHT PRECIP ACROSS THE SRN
TIER OF THE CWA JUST AFTER 12Z...BUT CLOUDS AND PRECIP WILL PUSH
SOUTH AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE GREAT
LAKES. HIGH TEMPS STILL COOL FOR THIS TIME OF YEAR...AND USED A
BLEND OF MOS/ADJ MAV.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
REGION REMAINS POSITIONED UNDER UPPER LVL LOW CENTERED OVER THE
CANADIAN MARITIMES WHILE SFC LOW SETTLES WELL OFFSHORE TO START
THE WORK WEEK. GENERALLY EXPECTING DRY CONDITIONS SUN NIGHT WITH A
BREAK IN THE SHORTWAVE ENERGY...THOUGH A SFC TROF COULD GENERATE
ISO SHOWERS SECOND HALF OF THE NIGHT. TEMPS DROPPING INTO THE 30S
FOR LOWS SUN NIGHT COULD RESULT IN ANY PCPN NEAR DAYBREAK BEING A
RAIN/SNOW OR EVEN ALL SNOW...WITH LITTLE TO NO ACCUM.
THE REGION WILL BE SANDWICHED BETWEEN HIGH PRESSURE OVER THE GREAT
LAKES AND THE LOW OFFSHORE MONDAY...RESULTING IN ELEVATED
WINDS...WITH GUSTS 25-30 MPH. POPS INCREASE AFTR 12Z MON AS NEXT
SHORTWAVE/VORT MAX ROUNDS THE LOW...WITH THE BETTER CHC WESTERN AND
EASTERN FRINGES OF THE CWA. THE STRONG SHORTWAVE WILL EXTEND ACROSS
THE MID ATLANTIC FOR MOST OF THE DAY...PRODUCING SCT SHOWERS.
PCPN TAPERS OFF MON EVENING AS UPPER LVL LOW PIVOTS OFFSHORE. AS THE
HIGH BUILDS IN...EXPECTING TO SEE WARMING TEMPS...WITH TEMPS NEARING
NORMAL BY MON NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
DESPITE THE COOL START AND CONTINUED CAA BEHIND THE COLD
FRONT...TEMPS WILL REBOUND A FEW DEGREES TUE AS DECREASING CLOUDS
ALLOW THE LATE APRIL SUN TO DO ITS WORK. THIS SLOW WARMING TREND
CONTINUES INTO WED...WITH TEMPS BACK TO NEAR NORMAL...AS A WEAK AREA
OF HIGH PRESSURE BUILDS IN.
MODEL DIVERGENCE INCREASES SUBSTANTIALLY BY LATE WED INTO THU WITH
REGARDS TO DEVELOPING LOW OVER GOM. LATEST MODEL GUIDANCE APPEARS TO
SHUNT MAIN IMPACTS TO OUR SOUTH...WITH LITTLE QPF OVER CWA. 12Z GFS
FAR DIFFERENT FROM 00Z ECMWF...AS GFS HAS NO COASTAL LOW OFF THE
CAROLINA COAST AND ECMWF DOES. HAVE LOWERED POPS SOME FOR
THU...ALTHOUGH FOR CONSISTENCY AND TO AVOID JUMPING ON ONE MODEL
CYCLE STILL KEPT CHC POPS...ALTHOUGH THAT MIGHT BE TOO HIGH.
HIGH PRESSURE RETURNS BY FRIDAY...BRINGING NEAR NORMAL TEMPS.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
EXPECT VFR CONDITIONS THROUGH MID TO LATE DAY. PRECIP
WILL MOVE IN AND CIGS WILL LOWER. THIS EVENING EXPECT MVFR TO
LOCALLY IFR CIGS IN PRECIP...EXPECT BWI/IAD/DCA CIGS TO RANGE FROM
2-3 KFT THIS EVENING...LOCALLY DOWN TO 1KFT IN HEAVIER PRECIP.
OVERNIGHT...BWI AND IAD COULD SEE CIGS BLO 1KFT. WINDS WILL BE
UNDER 10 KTS THROUGH THE PERIOD.
VFR CONDITIONS SUN-SUN NIGHT. SUB-VFR CONDITIONS PSBL MON WITH ANY
RAIN SHOWER. GUSTY NW WINDS WITH GUSTS 20-25 KTS PSBL AS WELL
DURING THE DAY MON...DIMINISHING AFTR SUNSET. MVFR CIGS MAY LINGER
THRU MON NIGHT.
NOT EXPECTING AVIATION CONCERNS TUE/WED WITH VFR CONDITIONS.
&&
.MARINE...
WINDS EXPECTED TO BE BELOW 10 KTS ACROSS THE WATERS TODAY AND
VARIABLE IN DIRECTION. RAIN WILL OVERSPREAD THE WATERS THIS
AFTERNOON INTO THIS EVENING. WINDS REMAIN LESS THAN 10 KTS THROUGH
SUN MORNING...INCREASING SUN AFTN. GUSTS COULD BRIEFLY TOUCH 18-20
KTS SUN AFTN WITH NORTHERLY CHANNELING.
SUB-SCA CONDITIONS INITIALLY SUN EVENING...WITH INCRSG
WINDS OVERNIGHT. SCA CONDITIONS WITH GUSTS UP TO 20 KTS AS EARLY AS
THE SECOND HALF OF SUN NIGHT...BCMG MORE LIKELY AFTR DAYBREAK MON.
GUSTS UP TO 30 KTS PSBL ON THE CHESAPEAKE BAY DURING THE DAY. SCA
GUSTS CONTINUE THRU MON NIGHT.
SCA IS POSSIBLE TUE UNTIL THE PRESSURE GRADIENT WEAKENS WITH
DEPARTING LOW. PRESSURE GRADIENT RELAXES ENOUGH FOR A RETURN TO
LIGHT WINDS BY WED.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...SEARS
LONG TERM...MSE
AVIATION...SEARS/MSE/SMZ
MARINE...SEARS/MSE/SMZ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
145 PM EDT SAT APR 25 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 AM EDT SAT APR 25 2015
LIGHT RAIN SCATTERED AROUND THE AREA EARLY THIS MORNING WILL
DIMINISH AND MOVE SOUTH OF THE AREA DURING THE DAY TODAY. SKIES WILL
THEN CLEAR OUT FROM NORTH TO SOUTH LATER IN THE DAY. HIGH PRESSURE
WILL THEN BUILD IN ACROSS THE AREA FOR THE DAY ON SUNDAY...BRINGING
A COOL AND NICE DAY TO THE AREA.
THE FIRST PORTION OF THE UPCOMING WEEK LOOKS TO BE MAINLY DRY. SOME
CLOUDS MAY ROTATE IN FROM THE NE ON MONDAY AS A WAVE OF LOW PRESSURE
MOVES BY JUST EAST OF THE STATE. THE NEXT CHANCE OF RAIN WILL THEN
COME ON WEDNESDAY. TEMPERATURES WILL GRADUALLY MODERATE TO NEAR
AVERAGE...AND POTENTIALLY ABOVE AVERAGE LATE NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1145 AM EDT SAT APR 25 2015
WILL KEEP THE CHANCE OF LIGHT RAIN THIS AFTERNOON LIMITED TO AREAS
SOUTH OF A LINE FROM ROUGHLY HOLLAND TO JACKSON. LATEST SHORT
RANGE GUIDANCE SUCH AS THE HRRR AND RADAR TRENDS SUPPORT THIS
IDEA.
THE CLOUD FCST IS A BIT TRICKY NORTH OF I-96 AS LATEST VISIBLE
IMAGE SHOWS SOME THINNING TAKING PLACE IN THE MID CLOUD DECK. WILL
HAVE SKIES BECOMING PTLY TO MSTLY SUNNY UP NORTH BUT REMAINING
MOSTLY CLOUDY NEAR AND SOUTH OF I-96. WARMEST HIGH TEMPS THIS
AFTERNOON SHOULD WEST OF HIGHWAY 131 AND NORTH OF I-96 WHERE
READINGS MAY APPROACH LATER TODAY 60 DEPENDING ON AMOUNT OF
CLEARING.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 328 AM EDT SAT APR 25 2015
THE ONLY REAL CHALLENGE IN THE SHORT TERM IS DEALING WITH THE RAIN
CHCS DURING THE DAY TODAY WITH THE UPPER SYSTEM TRYING TO MOVE INTO
THE AREA.
THE TREND IN THE LATEST DATA ALL POINTS TOWARD ALMOST ALL
OF THE RAIN MISSING THE CWFA AFTER THE LINGERING LIGHT RAIN EARLY
THIS MORNING. THE UPPER TROUGH DROPPING INTO THE AREA ON THE WRN
FLANK OF THE UPPER LOW NEAR MAINE HAS TRENDED QUICKER/STRONGER AND
IS DEFLECTING THE PLAINS LOW FURTHER SOUTH. LATEST SATELLITE IMAGERY
APPEARS TO SUPPORT THE LIMIT IN NORTHWARD PROGRESS OF THE LOW IN THE
PLAINS. WE HAVE LEFT A SLIGHT CHC OF RAIN FOR THE DAYLIGHT HOURS
ALONG/SOUTH OF I-94.
ONCE THE TROUGH MOVES THROUGH THIS AFTERNOON...SKIES WILL CLEAR OUT
FROM NORTH TO SOUTH ACROSS THE AREA. WE WILL SEE A QUIET AND DRY
PERIOD SETTLE IN FOR TONIGHT THROUGH SUN NIGHT. THIS WILL BRING A
MILDER DAY ON SUN WITH A DECENT AMOUNT OF SUNSHINE. WE COULD BE
LOOKING AT A COUPLE OF NIGHTS/MORNINGS WITH SOME FROST AND POSSIBLE
HEADLINES FOR LOCATIONS IN THE GROWING SEASON ALREADY AS TEMPS WILL
BE DROPPING INTO THE MID 30S. ENOUGH WIND MAY REMAIN UP SUN NIGHT TO
PREVENT FROST DEVELOPMENT.
WE ARE WATCHING FOR THE POTENTIAL TO POSSIBLY NEED TO ADD SOME LOW
CHCS OF PCPN IN FOR THE DAY ON MON. ANOTHER TROUGH WILL ROTATE SOUTH
THROUGH THE ERN PORTION OF THE STATE ON MON. SOME MOISTURE WILL
ADVECT IN ALSO WITH THE TROUGH. MOISTURE WILL BE RATHER SHALLOW IN
NATURE...SO WE ARE THINKING THAT AN INCREASE IN CLOUD COVER RIGHT
NOW FOR THE ERN SECTION OF THE CWFA IS APPROPRIATE AT THIS TIME.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 AM EDT SAT APR 25 2015
THE LONG TERM PERIOD LOOKS TO BE QUITE UNEVENTFUL WITH MODERATING
TEMPERATURES AND VERY LITTLE PRECIPITATION. THE UPPER PATTERN WILL
GRADUALLY TREND TOWARDS HIGHER HEIGHTS AND EVEN RIDGING BY NEXT
WEEKEND. 850MB TEMPERATURES WARM FROM AROUND ZERO C MONDAY
NIGHT...TO NEAR +10 C NEXT FRI/SAT. HIGH TEMPERATURES SHOULD WARM
FROM AROUND 60 ON TUESDAY TO AROUND 70 BY NEXT SATURDAY. NEXT
SUNDAY/S HIGHS COULD BE WELL INTO THE 70S WITH BOTH THE ECWMF AND
THE GFS INDICATING +12 C AT 850MB/S.
HAVE DRY CONDITIONS IN ALL FORECAST PERIODS EXCEPT WEDNESDAY AND
WEDNESDAY NIGHT OF THE UPCOMING WEEK. THE ECWMF STILL BRINGS IN A
SHORTWAVE TROUGH ALOFT ALONG WITH SOME MOISTURE...70-80PCT IN THE
1000-700MB LAYER. ONLY HAVE A 20PCT CHANCE OF LIGHT RAIN SHOWERS WED
AND WED NIGHT AT THIS POINT. WE WILL WATCH TRENDS WITH THIS WEAK
SYSTEM AND NUDGE PROBABILITIES FOR PRECIPITATION ACCORDINGLY.
OVERALL...SURFACE HIGH PRESSURE WILL BE IN PLACE DURING THE LONG
TERM WITH NO SIGNIFICANT LOW PRESSURE SYSTEMS OR FRONTAL PASSAGES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 142 PM EDT SAT APR 25 2015
SKIES ARE CLEARING FROM NORTH TO SOUTH. HOWEVER...SOME
INTERMITTANT MVFR CIGS REMAIN A POSSIBILITY THIS AFTERNOON FOR THE
SOUTHERN TAF SITES WHICH ARE CLOSER TO THE RAIN FALLING ACROSS
NORTHERN INDIANA. THOSE SITES SHOULD EVENTUALLY SCATTER OUT
TONIGHT. VFR CIGS AROUND 5K FT WILL MOVE INTO CENTRAL LOWER SUNDAY
MORNING FROM ONTARIO.
&&
.MARINE...
ISSUED AT 328 AM EDT SAT APR 25 2015
NO MARINE HEADLINES ARE EXPECTED FOR THE NEXT FEW DAYS. WE WILL HAVE
BREEZY CONDITIONS HOWEVER WITH WINDS JUST A NOTCH BELOW SMALL CRAFT
ADVISORY CRITERIA AROUND 15 TO 20 KNOTS LIKELY THROUGH MON. WINDS
SHOULD TEND TO DROP OFF TOWARD THE MID PORTION OF NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 1157 AM EDT SAT APR 25 2015
RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE STEADY OR SLOWLY
FALLING. RAIN IS POSSIBLE ACROSS SOUTHERN LOWER MICHIGAN SOUTH OF
INTERSTATE 96 INTO TONIGHT. ACCUMULATIONS SHOULD BE UNDER A QUARTER
OF AN INCH. DRY WEATHER THEN RETURNS THROUGH THE WEEK. BRIEF RISES
ARE POSSIBLE ON THE SOUTHERN RIVERS... BUT RIVER FLOODING IS NOT
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...DUKE
AVIATION...99
HYDROLOGY...63
MARINE...NJJ
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1118 AM CDT SAT APR 25 2015
.UPDATE...NEWLY ISSUED SEVERE THUNDERSTORM WATCH IS NOW IN EFFECT FOR
MY SOUTHERNMOST COUNTIES GENERALLY EAST OF I-55. THIS IS THANKS TO
ANOTHER COMPLEX OF SHOWERS AND STORMS CURRENTLY MOVING ACROSS SOUTH
CENTRAL LOUISIANA AND TRACKING TO THE EAST/NORTHEAST. IT IS IN THIS
AREA WHERE THE AIRMASS HAS BEEN VIRTUALLY UNTOUCHED BY LAST NIGHTS
STORMS AND SOME OUTFLOW BOUNDARY LIKELY HAS BEEN LAYED OUT OVER THE
REGION. SHORT TERM GUIDANCE INDICATES THAT THERE IS PLENTY OF LAPSE
RATE DOWN IN THIS REGION WITH VERTICAL TOTALS AROUND 28-30C. WHILE
LOWER LEVEL SHEAR ISNT HUGE...DEEP LAYER SHEAR IS SUFFICIENT FOR
ORGANIZED STORMS THAT COULD BRING SOME DAMAGING WIND GUSTS. SEVERE
THUNDERSTORM WARNINGS HAVE ALREADY GONE OUT TO OUR SOUTH WHERE THE
STRONGEST...MOST ORGANIZED CONVECTION CURRENTLY IS AND IS NOT OUT OF
THE QUESTION FOR THIS TO MOVE INTO MY SOUTHEASTERN COUNTIES THROUGH
THE EARLY AFTERNOON HOURS AS DAYTIME HEATING HELPS CONTRIBUTE TO
MAKING THE ATMOSPHERE MORE UNSTABLE. CURRENT LIMITED OUTLOOK IN THE HWO
AND GRAPHICS APPEAR REASONABLE. THE HRRR AGAIN SEEMS TO HANDLE THE
ONGOING ACTIVITY WELL THIS MORNING AND SHOWS A FEW BETTER CONVECTIVE
CELLS IN MY FAR SOUTH THROUGH THE EARLY AFTERNOON BEFORE EXITING
BEFORE 00Z. FURTHER NORTH...THE ATMOSPHERE...WHILE STILL MOIST...IS
MORE STABLE FROM OVERNIGHT CONVECTION AND SHOULD BE LIMITED IN THE
AMOUNT OF STORM ACTIVITY WE SEE. GOING FORECAST HANDLES MUCH OF THIS
WELL AND ONLY INCREASED POPS IN THE SOUTH WHERE RAIN APPEARS
IMMINENT. /28/
&&
.AVIATION...VERY MOIST LOWER LEVELS ARE KEEPING PLENTY OF IFR
CATEGORY STRATUS AROUND THIS MORNING...BUT HEATING SHOULD MIX CIGS
UP INTO VFR CATEGORY THIS AFTERNOON THROUGH THE EVENING AND BRING
THE POTENTIAL FOR ISOLATED TSRA CONTAINING HAIL AND DAMAGING WIND
GUSTS. THE EXCEPTION WILL BE IN THE HBG/PIB AREA WHERE A CONVECTIVE
COMPLEX OVER SRN/CNTRL LA WILL MOVE EAST AND BRING TSRA AND LOWER
CIGS/VSBY DURING THE EARLY/MID AFTERNOON. LATE TONIGHT THROUGH EARLY
SUNDAY MORNING...IFR/LIFR CATEGORY STRATUS WILL REDEVELOP MAINLY
ALONG/S OF THE TVR-JAN-MEI CORRIDOR. THE SHALLOW MOIST LAYER SHOULD
MIX OUT QUICKLY BY MID MORNING. /EC/
&&
.PREV DISCUSSION... /ISSUED 500 AM CDT SAT APR 25 2015/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT...IT HAS BEEN AN ACTIVE
NIGHT...ESPECIALLY NORTH OF INTERSTATE TWENTY...AS RESIDENTS OF THE
LOWER MS VALLEY HAVE HAD TO DEAL WITH A BOWING LINE OF THUNDERSTORMS
WITH POCKETS OF VERY STRONG WINDS. THERE WAS ALSO A HANDFUL OF RADAR
AND REPORTED DAMAGE SIGNATURES SUGGESTIVE OF BRIEF TORNADOES
SPINNING UP WITH SOME OF THE BOWING LINE SEGMENTS...BUT WE WILL HAVE
TO WAIT UNTIL LATER TODAY TO START SURVEY EFFORTS WHICH MAY OR MAY
NOT CONFIRM TORNADO TOUCHDOWNS. AS I WRITE THE TAIL END OF THIS LINE
OF THUNDERSTORMS IS ABOUT TO EXIT INTO ALABAMA WITH A REMNANT
OUTFLOW BOUNDARY SLOWLY SINKING SOUTH TOWARD THE HIGHWAY 84
CORRIDOR. TORNADO WATCH NUMBER 106 STILL IN EFFECT FOR A FEW
COUNTIES IN EAST CENTRAL MS WILL LIKELY BE CANCELLED VERY SHORTLY
AFTER AFOREMENTIONED LINE ENTIRELY CLEARS TO THE EAST.
DESPITE THE BULK OF STORMS EXITING EARLY THIS MORNING THE FORECAST
FOR OUR REGION TODAY WILL BE TRICKY OWING TO THE FACT THAT THE
SOUTHERN FRINGE OF A SOUTHERN STREAM DISTURBANCE STILL HAS TO PASS
THROUGH THE AREA BEFORE EVENING. WINDS THROUGHOUT THE ATMOSPHERE
WILL BE GRADUALLY VEERING THROUGH THE DAY...WHICH IN GENERAL WILL
HAVE THE EFFECT OF LOWERING MOISTURE LEVELS (ALTHOUGH MAYBE NOT
RIGHT AT THE SURFACE). BEST MOISTURE DEPTH AND USABLE INSTABILITY
(WHICH COULD BE QUITE IMPRESSIVE CONSIDERING COLD TEMPS ALOFT) WILL
RESIDE SOUTH OF I-20 WITH THE LINGERING EFFECT OF THE BAROCLINIC
ZONE LEFT IN THE WAKE OF OVERNIGHT STORMS PERHAPS ACTING AS A
TRIGGER FOR CONVECTIVE INITIATION IN THOSE PARTS. ANY DEEP
CONVECTION THAT GETS GOING IN THE UNSTABLE AND SHEARED ENVIRONMENT
WILL POTENTIALLY BE TROUBLE AND WORTH OF KEEPING A MENTION OF SEVERE
POTENTIAL IN SOUTHERN ZONES FOR PRIMARILY THE RISK OF DAMAGING WINDS
AND HAIL. FURTHER NORTH THE DRYING MID LAYERS OF THE ATMOSPHERE WILL
BE A CONSIDERABLE HINDRANCE TO DEEP...VIGOROUS...CONVECTION AND IT
IS MOST LIKELY THOSE AREAS WILL REMAIN DRY LATER TODAY. HOWEVER...IT
IS WORTH NOTING A ONE OR TWO HIRES MODEL RUNS HAS PRODUCED A STRAY
POTENT STORM ACROSS THE NORTH DESPITE THE MOISTURE DEFICIENCIES SO
IT IS AN ASPECT OF THE FORECAST THAT WILL HAVE TO BE MONITORED
CLOSELY THROUGHOUT THE DAY.
EXPECT ALL LINGERING LATE AFTERNOON CONVECTION TO DIE IN THE EARLY
EVENING WITH DRY WEATHER OVERNIGHT. THE ACTUAL COLD FRONT WILL STILL
REMAIN OFF TO OUR NORTH SO TEMPERATURES WILL GENERALLY REMAIN QUITE
MILD.
ON SUNDAY HIGHER CLOUDS WILL BEGIN INCREASING LATER IN THE DAY WITH
THE COLD FRONT TRAILING THE CURRENT SYSTEM FINALLY COMING INTO
NORTHERN ZONES IN THE AFTERNOON. BUT EVEN WITH THE ARRIVAL OF THIS
FRONT TEMPERATURES SHOULD PEAK WELL UP INTO THE 80S IN MOST AREAS
(WHICH SHOULD PROBABLY MAKE FOR THE WARMEST DAY OF THE YEAR SO FAR).
SOME LOCATIONS ALONG AND SOUTH OF THE HIGHWAY 84 CORRIDOR COULD EVEN
MANAGE TO HIT THE 90 DEGREE MARK.
ON SUNDAY NIGHT ANOTHER SOUTHERN STREAM DISTURBANCE MOVING INTO THE
PLAINS WILL BEGIN TRYING TO INITIATE MOISTURE RETURN UP INTO OUR
SOUTHERN ZONES NEAR THE INCOMING FRONT (WHICH SHOULD STALL BY LATER
IN THE NIGHT). A FEW OUTLYING MODEL SOLUTIONS DEPICT DECAYING STORM
CLUSTERS RIDING SOUTHEAST FROM THE RED RIVER VALLEY TOWARD OUR
REGION BEFORE DAYBREAK MONDAY ALONG THIS BAROCLINIC ZONE. POPS KEPT
AT NO MORE THAN 20 PERCENT THOUGH CONSIDERING THE CONSENSUS SOLUTION
IS TO REMAIN MOSTLY DRY UNTIL AT LEAST THE DAYTIME MONDAY. /BB/
LONG TERM...MONDAY THROUGH FRIDAY...MAIN FOCUS IN THE EXTENDED IS
ON RAIN CHANCES DURING THE FIRST HALF OF THE WEEK.
TO BEGIN THE NEW WORK WEEK THE UPPER LEVEL PATTERN WILL FEATURE
BROAD TROUGHING OVER MUCH OF THE CENTRAL AND EASTERN CONUS WITH
RIDGING ALONG THE PACIFIC COAST. A CLOSED OFF MID/UPPER LOW WILL
TRACK SLOWLY FROM THE TX PANHANDLE MONDAY INTO THE MID MS VALLEY BY
WEDNESDAY. WITH THE TROUGH DIGGING RATHER FAR TO THE SOUTH...THE
SURFACE LOW WILL ALSO FOLLOW A MORE SOUTHERLY PATH THAN RECENT
SYSTEMS...DEVELOPING CLOSE TO THE COAST DURING THE DAY MONDAY AND
TRACKING TO THE NORTH CENTRAL GULF OFF THE MS/AL COAST BY TUESDAY
NIGHT.
AS DISTURBANCES PINWHEEL AROUND THE UPPER LOW...SHOWERS WILL SPREAD
BACK INTO THE AREA MONDAY INTO MONDAY NIGHT AHEAD OF THE SYSTEM.
EVEN BETTER RAIN CHANCES LOOK TO EXIST MONDAY NIGHT OVERNIGHT INTO
TUESDAY AS AN INVERTED TROUGH EXTENDING NORTHWARD FROM THE SURFACE
CYCLONE SHIFTS ACROSS THE FORECAST AREA. AS WE REMAIN ON THE NORTH
SIDE OF THE LOW TRACK...SURFACE BASED INSTABILITY WILL BE VERY
LIMITED THOUGH THUNDER WILL REMAIN POSSIBLE THANKS TO ELEVATED
INSTABILITY AND RESPECTABLE DEEP LAYER SHEAR. AS MENTIONED IN
PREVIOUS DISCUSSIONS THERE IS SOME POTENTIAL FOR COASTAL CONVECTION
TO LIMIT ACTIVITY ACROSS OUR AREA DURING A PORTION OF THIS TIME
FRAME.
PRECIP WILL TAPER OFF WEDNESDAY AS THE SYSTEM SHIFTS EAST OF THE
AREA. AS THE UPPER TROUGH SHIFTS TO THE ATLANTIC SEABOARD...GUIDANCE
SHOWS GOOD AGREEMENT ON UPPER RIDGING BUILDING ACROSS THE REMAINDER
OF THE COUNTRY...WITH A BROAD SURFACE HIGH BUILDING OVER OUR AREA
BRINGING DRY WEATHER THROUGH THE END OF THE WEEK. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 85 67 88 61 / 37 11 6 15
MERIDIAN 83 66 87 59 / 43 13 6 12
VICKSBURG 85 66 87 62 / 34 10 7 19
HATTIESBURG 85 68 90 65 / 96 11 6 15
NATCHEZ 85 67 87 64 / 95 8 5 19
GREENVILLE 85 63 82 58 / 14 7 7 19
GREENWOOD 85 62 83 56 / 14 9 6 14
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/EC/BB/DL
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1113 AM CDT Sat Apr 25 2015
.UPDATE...
Issued at 1113 AM CDT SAT APR 25 2015
Have sent a small update to the forecast to account for precipitation
trends and where the best chances for renewed convection may exist
this afternoon. Surface analysis shows the surface low basically over
the KC metro with a warm front extending eastward roughly along the
MO river. This boundary is going to need to be watched for possible
renewed convection. The NAM and the RAP both show strong convergence
along this boundary later today with the NAM showing decent buildup
of instability right along the boundary. Cold 500mb temperatures of
-15C to -17C will aid in stretching any potential updraft. These
parameters are favorable for potential funnels this afternoon.
However there are some weaknesses. The position/orientation of the
surface low nearly under to potentially behind the 500mb low and the
opening of the upper low itself may be problematic for these hard to
predict events. Given the strength of the convergence along the
boundary and the strong shearing associated with boundary, if an
updraft can root on the boundary, I would not be surprised to reports
of funnel clouds stream in. The greatest potential for this will be
roughly along the I-70 corridor in our eastern zones. Have increased
PoPs in this area based short term model trends for the afternoon and
then quickly dissipate them this evening when any surface heating is
lost.
&&
.DISCUSSION...
Issued at 400 AM CDT SAT APR 25 2015
Remnants of Friday`s severe weather across central Kansas is
currently moving through the area, and is rather weak. Scattered
thunderstorms are located across most of northwest Missouri and
northeast Kansas, but lack of any appreciable instability has kept
these storms from becoming more than a brief shower as they roll
through. Surface analysis around 08z indicates that the surface low
is still to the west of the forecast area, and that is also
represented by general southeasterly surface winds across most of
the area. While the sun is still down these showers will remain
relatively light, but as the day wears on and the mid level trough -
which is currently stacked on top of the aforementioned low just
west of here - rolls through the area more scattered showers will
form. There should be a slightly higher level of instability across
the area today, with the cooler temperatures associated with the mid
level trough overhead. So, some storms could grow tall and produce
some small hail. As the mid level trough moves through, it generally
opens up and loses some of its organization. The areas of low
pressure within the column also become a bit disjointed through the
day, so a traditional cold core thunderstorm/funnel day does not
appear to be in the cards, but a few storms through the day could
produce some small hail, and periods of heavy rain and gusty winds.
The focus for thunderstorm activity will be along a sagging cold
front that will drop south along with the surface low. The enhanced
convergence along that boundary should aid in getting storms fired
up. The boundary will initially be located north of the forecast
area, but by noon should be located along/near Interstate 70. By
tonight the cold front will be located south of the area, with a
surface ridge nosing in. This will effectively scour out the
moisture, and end any precipitation chances, likely by tonight.
With the cool dry air working its way into the area the next few
nights could be chilly, with lows in the upper 30s along the IA/MO
border, and 40s farther south. But with good insolation through the
day highs for the rest of the weekend and into next week will follow
a gradual warming trend, with 60s anticipated through early next
week, then well into the 70s by late next week. With shortwave
ridging over the area, despite the warmer and moister air moving in
through the late part of the week mid level ascent will be lacking
and low level convergence triggers will be absent, thus a dry
forecast is on tap throughout the next week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 547 AM CDT SAT APR 25 2015
Scattered showers and thunderstorms will remain in and around the
aviation terminals through at least the mid morning hours before
moving out of the area. Expect ceilings to bounce between MVFR and
VFR through that time period, with a gradual deterioration to
prevailing MVFR conditions up on frontal passage around 16z. Expect
the stratus to remain over the area through the remainder of the
forecast period. Guidance does suggest that CIGs will come down to
IFR levels late in the forecast period, but for now will keep things
in MVFR.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...CDB
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
340 PM PDT SAT APR 25 2015
.SYNOPSIS...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CAN BE
EXPECTED ACROSS THE SOUTHERN GREAT BASIN AND MOJAVE DESERT MAINLY
THIS EVENING. VERY STRONG WINDS ARE ANTICIPATED ACROSS THE WESTERN
MOJAVE DESERT CREATING AREAS OF BLOWING DUST AND HAZE. GUSTY NORTH
WINDS ARE EXPECTED ACROSS THE REGION SUNDAY WITH IMPROVING
CONDITIONS AND A WARMING TREND COMMENCING DURING THE WORKWEEK.
&&
.SHORT TERM...THROUGH SUNDAY NIGHT.
BROKEN LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS HAS DEVELOPED
ALONG A COLD FRONT FROM DEATH VALLEY N.P - BEATTY - NORTHEAST OF
RACHEL IN LINCOLN COUNTY. THIS FRONT IS ASSOCIATED WITH A POTENT
SHORTWAVE TROUGH DIGGING INTO THE SOUTHERN GREAT BASIN/MOJAVE DESERT
THIS AFTERNOON.
LATEST HRRR SHOWS THIS BAND HOLDING TOGETHER AS IT CONTINUES TO MOVE
SOUTHEAST AROUND 20-25 MPH. THAT WOULD PLACE THE LINE THROUGH THE
PAHRUMP VALLEY BETWEEN 4-6 PM AND THE LAS VEGAS VALLEY BETWEEN 5 AND
7 PM. NORTHERN SEGMENT OF THE LINE WILL CONTINUE EAST ACROSS LINCOLN
COUNTY WITH THE LINE FORECAST TO CLEAR LINCOLN COUNTY BETWEEN 6-7
PM. PRECIPITATION WILL BE LAST TO CLEAR THE LAKE MEAD NRA AND MOHAVE
COUNTY WHICH WON`T OCCUR UNTIL AFTER MIDNIGHT.
THUNDERSTORMS CAPABLE OF PRODUCING WIND GUSTS UP TO 40 MPH, SMALL
HAIL AND BRIEF HEAVY RAIN.
HIGH WIND WARNING PANNING OUT IN THE THE WESTERN MOJAVE DESERT OF
SAN BERNARDINO COUNTY AS WE HAVE SEEN WIND GUSTS AT FORT IRWIN AND
BARSTOW-DAGGETT IN EXCESS OF 60 MPH. WILL KEEP HIGH WIND WARNING AND
WIND ADVISORY POSTED UNTIL 11 PM PDT.
AN UPPER LOW WILL FORM OVER NEW MEXICO SUNDAY KEEPING THE REGION
UNDER A COOL NORTH FLOW. IN ADDITION TO THE THOSE WIND PRODUCTS
ALREADY OUT ADDED A WIND ADVISORY FOR POST FRONTAL NORTHWEST WINDS
FOR ESMERALDA/CENTRAL NYE COUNTIES THROUGH SUNDAY AFTERNOON. ALSO,
DECIDED TO ISSUE A LAKE WIND ADVISORY FOR THE LAKE MEAD NRA
SOUTHWARD TO LAKE HAVASU. CAN NOT RULE OUT AN ISOLATED SHOWER OVER
NORTHERN MOHAVE COUNTY WITHIN AN AREA OF WRAP AROUND MOISTURE.
.LONG TERM...MONDAY THROUGH FRIDAY.
ANY LINGERING SHOWERS WOULD BE OVER EXTREME EASTERN LINCOLN COUNTY
AND EASTERN MOHAVE COUNTY EARLY BEFORE DRY CONDITIONS SET IN. EXPECT
GUSTY NORTH WINDS OF 20-30 MPH ACROSS MUCH OF THE AREA, WITH HIGHER
WIND SPEEDS LIKELY ALONG THE COLORADO RIVER VALLEY. WILL KEEP AN EYE
ON THE POTENTIAL FOR A WIND HEADLINE FOR THE RIVER ZONES. BREEZY
NORTH WINDS WILL LINGER INTO MONDAY, YET LIGHTER THAN SUNDAY.
STRONGEST GUSTS WILL REMAIN ALONG THE COLORADO RIVER VALLEY.
WINDS WILL BE WEAKER AND TREND TOWARD TYPICAL DIURNAL DIRECTIONS
TUESDAY AND WEDNESDAY AS HIGH PRESSURE FULLY TAKES CONTROL.
TEMPERATURES WILL ALSO TREND MUCH WARMER THROUGH THE WEEK, WITH
AFTERNOON HIGHS CLIMBING ROUGHLY 10 DEGREES ABOVE NORMAL FOR THE
LATTER HALF OF THE WEEK. THERE REMAINS SOME DIFFERENCE IN STRENGTH
AND TIMING, BUT MODELS CONTINUE TO INDICATE A LOW PRESSURE SYSTEM
MOVING THROUGH THE PACIFIC NORTHWEST /PERHAPS NORTHERN CALIFORNIA/
LATE THURSDAY THROUGH FRIDAY. SOME BREEZY SOUTHWEST WINDS ARE
POSSIBLE THURSDAY AFTERNOON AND AGAIN FRIDAY. BREEZY CONDITIONS MAY
LAST INTO THE WEEKEND, AS SOME WEAK TROUGHING LINGERS ACROSS THE
GREAT BASIN. FOR NOW, IT APPEARS ANY MOISTURE WITH THIS TROUGH IS
EXTREMELY LIMITED AND SHOULD STAY NORTH OF THE FORECAST AREA.
&&
.AVIATION...FOR MCCARRAN...SCATTERED THUNDERSTORMS NEARING THE
PAHRUMP VALLEY WILL CONTINUE TO DEVELOP EAST TOWARD THE LAS VEGAS
VALLEY AFTER 4 PM. SHOWERS AND THUNDERSTORMS WILL CONTINUE AROUND
THE LAS VEGAS VALLEY IMPACTING ALL CORRIDORS THROUGH ABOUT 7 PM THIS
EVENING. THE WIND DIRECTION WILL GET DIFFICULT TO FORECAST WITH NEAR
BY STORMS SO OPTED FOR A VARIABLE GROUPING IN THE TAF. SOME BLOWING
DUST COULD ALSO BRING A REDUCTION IN THE VISIBILITY. NOT CONFIDENT
ENOUGH AT THIS TIME TO MENTION THE LOWER VISIBILITY. AFTER THE
STORMS CLEAR WINDS SHOULD SETTLE INTO A WESTERLY DIRECTION BEFORE
GOING MORE NORTHWESTERLY LATE TONIGHT THROUGH SUNDAY.
.FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...UNSETTLED WEATHER EXPECTED ACROSS THE REGION THIS
EVENING WITH STRONG AND GUSTY WEST-SOUTHWEST WINDS EXPECTED ACROSS
THE MOJAVE DESERT EASTWARD INTO NORTHWEST ARIZONA. WINDS OF 20 TO 30
KTS WITH GUSTS TO 40 EXPECTED WITH EVEN STRONGER WINDS IN THE KDAG
AREA AND FAR WESTERN MOJAVE DESERT WHERE GUSTS WILL EXCEED 50KTS.
AREAS OF BLOWING DUST LIKELY WITH DANGEROUS CROSSWINDS ON NORTH-
SOUTH ORIENTED RUNWAYS. FURTHER NORTH WIDESPREAD SHOWERS AND TSTORMS
LIKELY ACROSS THE SOUTHERN GREAT BASIN MAINLY NORTH OF I-15 THROUGH
00Z. SHOWERS EXPAND ACROSS NORTHWEST ARIZONA AND FAR SOUTHERN NEVADA
AFTER 00Z AS A COLD FRONT MOVES THROUGH AND WINDS SHIFT TO THE
NORTHWEST.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT ACCORDING TO
STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE...PIERCE
SHORT TERM/AVIATION...OUTLER
LONG TERM...PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
546 PM EDT SAT APR 25 2015
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTH AND WILL BE NEAR OR
JUST NORTH OF THE AREA SUNDAY MORNING BEFORE GETTING SHOVED
SOUTHWARD SUNDAY AFTERNOON AND EVENING. A SMALL RISK FOR STRONG TO
SEVERE THUNDERSTORMS WILL REMAIN INTO SUNDAY. DRY HIGH PRESSURE
WILL RETURN MONDAY INTO TUESDAY BEFORE A STORM SYSTEM IMPACTS THE
AREA DURING THE MIDDLE OF NEXT WEEK. DRY HIGH PRESSURE IS EXPECTED
TO RETURN BY FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 530 PM SATURDAY...BASED ON LATEST 88D RADAR MOSAIC TRENDS
AND LATEST VIS AND IR SAT IMAGERY TRENDS AND LATEST 18Z VARIOUS
MODEL RUNS...HAVE UPDATED EVENING AND OVERNIGHT POPS AND SKY
CONDITIONS. BASICALLY LOWERING POPS TRENDS THIS EVENING AND
OVERNIGHT TO LOW CHANCE/SLIGHT CHANCE/ISOLATED. IN ADDITION...HAVE
SKY CONDITIONS IN THE CLOUDY/MOSTLY CLOUDY/VARIABLY CLOUDY TREND
FOR THE EVENING THRU OVERNIGHT. IF SKIES PARTIALLY CLEAR
ENOUGH...FOG COULD BECOME AN ISSUE DURING THE PRE-DAWN SUNDAY
HOURS.
PREVIOUS........................................................
AS OF 300 PM SATURDAY...SEVERE THREAT HAS BECOME REMOTE FOR THE
DAYLIGHT HOURS. GUIDANCE AND OBSERVATIONS SHOW A STABLE ATMOSPHERE
WITH A SHIELD OF LIGHT AND COOL STRATIFORM RAIN MOVING EAST ACROSS
THE FORECAST AREA AND OUT TO SEA. AT THE SURFACE A DIFFUSE QUASI-
STATIONARY FRONT IS WAVERING ABOUT WHILE A WARM FRONT MOVES UP
FROM THE SOUTH. OVERALL SURFACE PATTERN IS NOT WELL DEFINED AND
ALTHOUGH THERE ARE DIFFERENCES AMONG GUIDANCE THE GENERAL TREND IS
TOWARDS WEAKER THAN ANTICIPATED CONVECTION AND SPARSER COVERAGE.
NAM AND GFS MOS GUIDANCE HAVE SLIGHT CHANCE FOR OVERNIGHT POPS.
CONSIDERING OTHER GUIDANCE ON HAND AND GENERAL UNCERTAINTY WILL
KEEP IN SLIGHT CHANCE TO CHANCE POPS FOR THE OVERNIGHT PERIOD.
BUFKIT AND OTHER DATA SHOW BETTER INSTABILITY SHOWING UP THIS
EVENING AND OVERNIGHT SO MAKING CHARACTER OF PRECIP MORE
CONVECTIVE IN NATURE AND WILL INCLUDE SLIGHT CHANCE FOR THUNDER.
THE HRRR HAS BEEN VERY HELPFUL TODAY IN DEPICTING COVERAGE AND
TRENDS SO WILL CONTINUE TO LEAN ON ITS GUIDANCE FOR THE NEAR TERM.
THIS MODEL HAS ISOLATED TO SCATTERED SHOWERS FOR THE REMAINDER OF
THE AFTERNOON WITH PERHAPS A MORE MODERATE LINE OF CONVECTION
MOVING THROUGH AROUND MIDNIGHT. EXTENSIVE CLOUD COVER AND WARM
FROPA WILL KEEP TEMPS OVERNIGHT ON THE MODERATE SIDE...IN VARIOUS
SHADES OF THE 60S. THIS IS NOT MUCH DIFFERENT THAN TODAYS DAYTIME
READINGS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...A WARM FRONT WILL BE SITUATED VERY NEAR OR
JUST N OF THE AREA SUNDAY MORNING. MODEL PROFILES SHOW A DEEP
WESTERLY FLOW WITH SIGNIFICANT MOISTURE RELEGATED TO THE LOWEST 3
KFT OR SO IN THE WARM SECTOR. A 50 KT JET WILL BE LOCATED 3-5 KFT
AGL SUNDAY. THE GFS SHOWS LITTLE IN THE WAY OF INSTABILITY ON SUN
WHILE THE NAM PORTRAYS MIXED LAYER CAPE VALUES UP TO AROUND 1500
J/KG AND THIS SEEMS MUCH MORE REASONABLE. THE INSTABILITY WILL BE
SHRINKING SOUTHWARD WITH TIME AS THE LAST OF THE WEAK WAVES OF LOW
PRESSURE MOVES OFFSHORE TO CONSOLIDATE AND STRENGTHEN WELL OFF
THE NC COAST. MODEL SOUNDINGS ACTUALLY SHOW A STRONG FRONTAL
INVERSION DEVELOPING FROM N TO S...LASTLY ACROSS THE SOUTHERN
GRAND STRAND AND SOUTH SANTEE RIVER AREAS BY MID AFTERNOON SUN.
CONFIDENCE IN TIMING IS NOT HIGH...BUT TRENDS LOOK TO BE ON THE
RIGHT TRACK. GIVEN MAGNITUDE OF DRY AIR IN STRONG AND DEEPENING
WESTERLY FLOW ALOFT...WOULD EXPECT COVERAGE OF CONVECTION TO BE
ISOLATED TO SCATTERED. CAN NOT RULE OUT AN ISOLATED STRONG OR
SEVERE THUNDERSTORM TO INCLUDE HAIL AND/OR STRONG TO DAMAGING WIND
GUSTS. THE SEVERE WEATHER RISK WILL BE PRIMARILY ACROSS THE
SOUTHERN REACHES OF OUR FORECAST AREA...WHERE INSTABILITY WILL BE
GREATEST...AS WELL AS PERHAPS WHERE SEABREEZE INTERACTS WITH THE
FRONT. ANY SEVERE WEATHER WILL INCLUDE STRONG TO DAMAGING WIND
GUSTS WILL SHOW POPS TRENDING LOWER FROM N TO S LATE IN THE
AFTERNOON AND THROUGH THE EVE HOURS.
A SERIES OF SHORTWAVE TROUGHS ROUNDING A RETROGRADING AN UPPER LOW
OFF THE NEW ENGLAND COAST WILL HELP TO REINFORCE THE COOLER AND
DRIER AIR ADVECTING INTO THE FORECAST AREA MON AND MON NIGHT. A
GOOD DEAL OF SUNSHINE MON WILL BE BATTLING THE COOL NW FLOW WITH
850 MB TEMPS DROPPING TO AROUND 3 DEG C.
HIGHS SUN WILL LIKELY VARY FROM N TO S AND DEPENDING ON CLOUD
COVER...THERE COULD BE A SIGNIFICANT TEMP GRADIENT ACROSS THE
AREA. WILL FORECAST LOWER TO MID 80S ACROSS THE SOUTH SANTEE
RIVER AREA WITH MID AND UPPER 70S ELSEWHERE. HOWEVER...THE
NORTHERN REACHES OF THE AREA COULD BE STYMIED IN THE LOWER 70S
GIVEN THEIR PROXIMITY TO THE BOUNDARY AND GREATER CLOUD COVER.
HIGHS ON SUN WILL BE IN THE LOWER 70S FOR THE MOST PART...ONE TO
TWO CATEGORIES BELOW NORMAL FOR THE WANING DAYS OF APRIL. AFTERNOON
RELATIVE HUMIDITY LEVELS WILL BE FALLING THROUGH THE 40S AND 30S
ON MON AS DRY AND COOL HIGH PRESSURE TO THE NW BUILDS INTO THE
EASTERN CAROLINAS. THE COOLEST NIGHT...MON NIGHT...WILL BE IN THE
MID AND UPPER 40S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY....MEDIUM RANGE GUIDANCE CONTINUES TO
STRUGGLE WITH THE EVOLUTION OF A MID LEVEL SYSTEM THAT WILL AFFECT
THE AREA TO SOME EXTENT FOR MIDWEEK. SEVERAL MODELS KEEP THE
TROUGH MORE PROGRESSIVE WHILE OTHERS PHASE THE SYSTEM WITH
NORTHERN STREAM ENERGY CREATING A MORE DYNAMIC SYSTEM AND PROLIFIC
RAIN MAKER FOR OUR AREA. UNTIL THE MODELS CONVERGE ON A DEPENDABLE
SOLUTION...PRUDENCE CALLS FOR KEEPING POPS IN THE FORECAST FROM
LATE TUESDAY THROUGH THURSDAY. NO CHANGES TO TEMPERATURE FORECAST
WHICH WILL BE A LITTLE BELOW CLIMATOLOGY.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...LIGHT RAIN HAS SPREAD OVER MOST OF THE CWA. THE PRECIP
IS STRATIFORM WITH NO CONVECTION IN THE REGION AT THIS TIME. SOME
ISOLATED CONVECTION IS POSSIBLE OVER OUR EXTREME SOUTHERN
BOUNDARIES...WITH MAINLY MVFR CEILINGS LATER THIS AFTERNOON AS THE
PRECIPITATION INDUCED CEILINGS LOWER. TONIGHT...MOST OF THE RAIN
WILL END... WITH LOWER CEILINGS EXPECTED. RATHER LOW CONFIDENCE ON
CEILINGS AND PRECIP FOR SUNDAY AS FRONTAL BOUNDARY REMAINS NEARLY ON
TOP OF US. SHOULD SEE A GOOD WESTERLY WIND TOWARD THE END OF THE
FORECAST PERIOD WITH LOW PRESSURE CENTERED JUST TO OUR NORTH.
EXTENDED OUTLOOK...VFR MONDAY AND TUESDAY. SHOWERS POSSIBLE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 530 PM SATURDAY...LATEST MODEL RUNS NOT ALL THAT CONVINCING
ENOUGH TO CHANGE THE CURRENT FORECAST WINDS AND SIGNIFICANT SEAS
TRENDS FOR THIS EVENING AND OVERNIGHT. WILL HOLD ONTO WHAT IS
CURRENTLY ADVERTISED...INCLUDING HOLDING OUT WITH THE ISSUANCE OF
A POSSIBLE SCEC.
PREVIOUS...................................................
AS OF 300 PM SATURDAY...SOUTH WINDS THIS AFTERNOON WILL BECOME SW
TONIGHT AS A WARM FRONT MOVES NORTH ACROSS THE WATERS. WINDS WILL
STAY IN THE GENERAL 10 TO 15 KT RANGE WITH 2 TO 4 FT OF SEAS FOR
MOST OF THE PERIOD. HOWEVER...THERE MAY BE A BRIEF PERIOD OF
HIGHER WINDS AND SEAS TONIGHT AS THE WARM FRONT APPROACHES THE
WATERS. IF SO...EXERCISE CAUTION HEADLINES MAY BE NEEDED.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...THE WIND DIRECTION WILL BE FROM THE W OR
SW SUN MORNING...THEN VEER TO THE NW AND N AS A FRONT SINKS BACK
TO THE S THROUGH THE DAY. THE FRONT MAY NOT MOVE S OF THE
SOUTHERNMOST WATERS TIL LATE AFTERNOON. THERE WILL BE A MODEST
SURGE SUN NIGHT AND THEN A SLIGHTLY STRONGER ONE MON NIGHT AS A
SERIES OF SHORTWAVE TROUGHS ROTATE AROUND UPPER LOW RETROGRADING
OFF THE NEW ENGLAND COAST. WINDS WILL BE STRONGEST WHEN THE WIND
DIRECTION IS FROM THE N OR NNW...UP TO 15 TO 20 KT MON NIGHT.
SEAS WILL BE 2 TO 4 FT MOST OF THE TIME. HOWEVER...EXPECT SEAS TO
BUILD UP TO 5 FT DURING THE SURGES...WITH THE GREATEST COVERAGE OF
5 FT SEAS MON NIGHT.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...DESPITE AN INTERESTING AND POSSIBLY
DYNAMIC SYNOPTIC WEATHER SCENARIO AT THE MID LEVELS...THE SURFACE
FEATURES DRIVING THE WINDS AND SEAS WILL BE RATHER BENIGN IN
COMPARISON. HIGH PRESSURE TO THE NORTH WILL MAINTAIN A NORTH TO
NORTHEASTERLY FLOW ACROSS THE WATERS THROUGH WEDNESDAY WITH SPEEDS
GENERALLY TEN KNOTS OR LESS. FORECAST CHALLENGE THEN ARISES AS
MODELS ARE STILL UNSURE HOW TO HANDLE LOW PRESSURE IN THE GULF OR
UP THE EAST COAST BOTH IN A PLACEMENT AND STRENGTH PERSPECTIVE.
WILL MAINTAIN THE MODEST OFFSHORE FLOW FOR THURSDAY DUE TO
UNCERTAINTY. SIGNIFICANT SEAS WILL BE 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH/REK
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
255 PM EDT SAT APR 25 2015
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTH AND WILL BE NEAR OR
JUST NORTH OF THE AREA SUNDAY MORNING BEFORE GETTING SHOVED
SOUTHWARD SUNDAY AFTERNOON AND EVENING. A SMALL RISK FOR STRONG TO
SEVERE THUNDERSTORMS WILL REMAIN INTO SUNDAY. DRY HIGH PRESSURE
WILL RETURN MONDAY INTO TUESDAY BEFORE A STORM SYSTEM IMPACTS THE
AREA DURING THE MIDDLE OF NEXT WEEK. DRY HIGH PRESSURE IS EXPECTED
TO RETURN BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SATURDAY...SEVERE THREAT HAS BECOME REMOTE FOR THE
DAYLIGHT HOURS. GUIDANCE AND OBSERVATIONS SHOW A STABLE ATMOSPHERE
WITH A SHIELD OF LIGHT AND COOL STRATIFORM RAIN MOVING EAST ACROSS
THE FORECAST AREA AND OUT TO SEA. AT THE SURFACE A DIFFUSE QUASI-
STATIONARY FRONT IS WAVERING ABOUT WHILE A WARM FRONT MOVES UP
FROM THE SOUTH. OVERALL SURFACE PATTERN IS NOT WELL DEFINED AND
ALTHOUGH THERE ARE DIFFERENCES AMONG GUIDANCE THE GENERAL TREND IS
TOWARDS WEAKER THAN ANTICIPATED CONVECTION AND SPARSER COVERAGE.
NAM AND GFS MOS GUIDANCE HAVE SLIGHT CHANCE FOR OVERNIGHT POPS.
CONSIDERING OTHER GUIDANCE ON HAND AND GENERAL UNCERTAINTY WILL
KEEP IN SLIGHT CHANCE TO CHANCE POPS FOR THE OVERNIGHT PERIOD.
BUFKIT AND OTHER DATA SHOW BETTER INSTABILITY SHOWING UP THIS
EVENING AND OVERNIGHT SO MAKING CHARACTER OF PRECIP MORE
CONVECTIVE IN NATURE AND WILL INCLUDE SLIGHT CHANCE FOR THUNDER.
THE HRRR HAS BEEN VERY HELPFUL TODAY IN DEPICTING COVERAGE AND
TRENDS SO WILL CONTINUE TO LEAN ON ITS GUIDANCE FOR THE NEAR TERM.
THIS MODEL HAS ISOLATED TO SCATTERED SHOWERS FOR THE REMAINDER OF
THE AFTERNOON WITH PERHAPS A MORE MODERATE LINE OF CONVECTION
MOVING THROUGH AROUND MIDNIGHT. EXTENSIVE CLOUD COVER AND WARM
FROPA WILL KEEP TEMPS OVERNIGHT ON THE MODERATE SIDE...IN VARIOUS
SHADES OF THE 60S. THIS IS NOT MUCH DIFFERENT THAN TODAYS DAYTIME
READINGS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...A WARM FRONT WILL BE SITUATED VERY NEAR OR
JUST N OF THE AREA SUNDAY MORNING. MODEL PROFILES SHOW A DEEP
WESTERLY FLOW WITH SIGNIFICANT MOISTURE RELEGATED TO THE LOWEST 3
KFT OR SO IN THE WARM SECTOR. A 50 KT JET WILL BE LOCATED 3-5 KFT
AGL SUNDAY. THE GFS SHOWS LITTLE IN THE WAY OF INSTABILITY ON SUN
WHILE THE NAM PORTRAYS MIXED LAYER CAPE VALUES UP TO AROUND 1500
J/KG AND THIS SEEMS MUCH MORE REASONABLE. THE INSTABILITY WILL BE
SHRINKING SOUTHWARD WITH TIME AS THE LAST OF THE WEAK WAVES OF LOW
PRESSURE MOVES OFFSHORE TO CONSOLIDATE AND STRENGTHEN WELL OFF
THE NC COAST. MODEL SOUNDINGS ACTUALLY SHOW A STRONG FRONTAL
INVERSION DEVELOPING FROM N TO S...LASTLY ACROSS THE SOUTHERN
GRAND STRAND AND SOUTH SANTEE RIVER AREAS BY MID AFTERNOON SUN.
CONFIDENCE IN TIMING IS NOT HIGH...BUT TRENDS LOOK TO BE ON THE
RIGHT TRACK. GIVEN MAGNITUDE OF DRY AIR IN STRONG AND DEEPENING
WESTERLY FLOW ALOFT...WOULD EXPECT COVERAGE OF CONVECTION TO BE
ISOLATED TO SCATTERED. CAN NOT RULE OUT AN ISOLATED STRONG OR
SEVERE THUNDERSTORM TO INCLUDE HAIL AND/OR STRONG TO DAMAGING WIND
GUSTS. THE SEVERE WEATHER RISK WILL BE PRIMARILY ACROSS THE
SOUTHERN REACHES OF OUR FORECAST AREA...WHERE INSTABILITY WILL BE
GREATEST...AS WELL AS PERHAPS WHERE SEABREEZE INTERACTS WITH THE
FRONT. ANY SEVERE WEATHER WILL INCLUDE STRONG TO DAMAGING WIND
GUSTS WILL SHOW POPS TRENDING LOWER FROM N TO S LATE IN THE
AFTERNOON AND THROUGH THE EVE HOURS.
A SERIES OF SHORTWAVE TROUGHS ROUNDING A RETROGRADING AN UPPER LOW
OFF THE NEW ENGLAND COAST WILL HELP TO REINFORCE THE COOLER AND
DRIER AIR ADVECTING INTO THE FORECAST AREA MON AND MON NIGHT. A
GOOD DEAL OF SUNSHINE MON WILL BE BATTLING THE COOL NW FLOW WITH
850 MB TEMPS DROPPING TO AROUND 3 DEG C.
HIGHS SUN WILL LIKELY VARY FROM N TO S AND DEPENDING ON CLOUD
COVER...THERE COULD BE A SIGNIFICANT TEMP GRADIENT ACROSS THE
AREA. WILL FORECAST LOWER TO MID 80S ACROSS THE SOUTH SANTEE
RIVER AREA WITH MID AND UPPER 70S ELSEWHERE. HOWEVER...THE
NORTHERN REACHES OF THE AREA COULD BE STYMIED IN THE LOWER 70S
GIVEN THEIR PROXIMITY TO THE BOUNDARY AND GREATER CLOUD COVER.
HIGHS ON SUN WILL BE IN THE LOWER 70S FOR THE MOST PART...ONE TO
TWO CATEGORIES BELOW NORMAL FOR THE WANING DAYS OF APRIL. AFTERNOON
RELATIVE HUMIDITY LEVELS WILL BE FALLING THROUGH THE 40S AND 30S
ON MON AS DRY AND COOL HIGH PRESSURE TO THE NW BUILDS INTO THE
EASTERN CAROLINAS. THE COOLEST NIGHT...MON NIGHT...WILL BE IN THE
MID AND UPPER 40S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY....MEDIUM RANGE GUIDANCE CONTINUES TO
STRUGGLE WITH THE EVOLUTION OF A MID LEVEL SYSTEM THAT WILL AFFECT
THE AREA TO SOME EXTENT FOR MIDWEEK. SEVERAL MODELS KEEP THE
TROUGH MORE PROGRESSIVE WHILE OTHERS PHASE THE SYSTEM WITH
NORTHERN STREAM ENERGY CREATING A MORE DYNAMIC SYSTEM AND PROLIFIC
RAIN MAKER FOR OUR AREA. UNTIL THE MODELS CONVERGE ON A DEPENDABLE
SOLUTION...PRUDENCE CALLS FOR KEEPING POPS IN THE FORECAST FROM
LATE TUESDAY THROUGH THURSDAY. NO CHANGES TO TEMPERATURE FORECAST
WHICH WILL BE A LITTLE BELOW CLIMATOLOGY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...LIGHT RAIN HAS SPREAD OVER MOST OF THE CWA. THE PRECIP
IS STRATIFORM WITH NO CONVECTION IN THE REGION AT THIS TIME. SOME
ISOLATED CONVECTION IS POSSIBLE OVER OUR EXTREME SOUTHERN
BOUNDARIES...WITH MAINLY MVFR CEILINGS LATER THIS AFTERNOON AS THE
PRECIPITATION INDUCED CEILINGS LOWER. TONIGHT...MOST OF THE RAIN
WILL END... WITH LOWER CEILINGS EXPECTED. RATHER LOW CONFIDENCE ON
CEILINGS AND PRECIP FOR SUNDAY AS FRONTAL BOUNDARY REMAINS NEARLY ON
TOP OF US. SHOULD SEE A GOOD WESTERLY WIND TOWARD THE END OF THE
FORECAST PERIOD WITH LOW PRESSURE CENTERED JUST TO OUR NORTH.
EXTENDED OUTLOOK...VFR MONDAY AND TUESDAY. SHOWERS POSSIBLE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SATURDAY...SOUTH WINDS THIS AFTERNOON WILL BECOME SW
TONIGHT AS A WARM FRONT MOVES NORTH ACROSS THE WATERS. WINDS WILL
STAY IN THE GENERAL 10 TO 15 KT RANGE WITH 2 TO 4 FT OF SEAS FOR
MOST OF THE PERIOD. HOWEVER...THERE MAY BE A BRIEF PERIOD OF
HIGHER WINDS AND SEAS TONIGHT AS THE WARM FRONT APPROACHES THE
WATERS. IF SO...EXERCISE CAUTION HEADLINES MAY BE NEEDED.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...THE WIND DIRECTION WILL BE FROM THE W OR
SW SUN MORNING...THEN VEER TO THE NW AND N AS A FRONT SINKS BACK
TO THE S THROUGH THE DAY. THE FRONT MAY NOT MOVE S OF THE
SOUTHERNMOST WATERS TIL LATE AFTERNOON. THERE WILL BE A MODEST
SURGE SUN NIGHT AND THEN A SLIGHTLY STRONGER ONE MON NIGHT AS A
SERIES OF SHORTWAVE TROUGHS ROTATE AROUND UPPER LOW RETROGRADING
OFF THE NEW ENGLAND COAST. WINDS WILL BE STRONGEST WHEN THE WIND
DIRECTION IS FROM THE N OR NNW...UP TO 15 TO 20 KT MON NIGHT.
SEAS WILL BE 2 TO 4 FT MOST OF THE TIME. HOWEVER...EXPECT SEAS TO
BUILD UP TO 5 FT DURING THE SURGES...WITH THE GREATEST COVERAGE OF
5 FT SEAS MON NIGHT.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...DESPITE AN INTERESTING AND POSSIBLY
DYNAMIC SYNOPTIC WEATHER SCENARIO AT THE MID LEVELS...THE SURFACE
FEATURES DRIVING THE WINDS AND SEAS WILL BE RATHER BENIGN IN
COMPARISON. HIGH PRESSURE TO THE NORTH WILL MAINTAIN A NORTH TO
NORTHEASTERLY FLOW ACROSS THE WATERS THROUGH WEDNESDAY WITH SPEEDS
GENERALLY TEN KNOTS OR LESS. FORECAST CHALLENGE THEN ARISES AS
MODELS ARE STILL UNSURE HOW TO HANDLE LOW PRESSURE IN THE GULF OR
UP THE EAST COAST BOTH IN A PLACEMENT AND STRENGTH PERSPECTIVE.
WILL MAINTAIN THE MODEST OFFSHORE FLOW FOR THURSDAY DUE TO
UNCERTAINTY. SIGNIFICANT SEAS WILL BE 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...REK/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
204 PM EDT SAT APR 25 2015
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTH TODAY AND TONIGHT
BRINGING SHOWERS AND POTENTIALLY A FEW STRONG THUNDERSTORMS. THE
FRONT WILL STALL BEFORE BEING PUSHED SOUTH AS A COLD FRONT LATE
SUNDAY. DRY HIGH PRESSURE WILL RETURN MONDAY INTO TUESDAY BEFORE
ANOTHER STORM SYSTEM IMPACTS THE AREA THROUGH MID WEEK. DRY HIGH
PRESSURE IS EXPECTED TO RETURN BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM SATURDAY...SEVERE THREAT HAS BECOME REMOTE FOR THE
DAYLIGHT HOURS. GUIDANCE AND OBSERVATIONS SHOW A STABLE ATMOSPHERE
WITH A SHIELD OF LIGHT AND COOL STRATIFORM RAIN MOVING EAST ACROSS
THE FORECAST AREA AND OUT TO SEA. AT THE SURFACE A DIFFUSE QUASI-
STATIONARY FRONT IS WAVERING ABOUT WHILE A WARM FRONT MOVES UP
FROM THE SOUTH. OVERALL SURFACE PATTERN IS NOT WELL DEFINED AND
ALTHOUGH THERE ARE DIFFERENCES AMONG GUIDANCE THE GENERAL TREND IS
TOWARDS WEAKER THAN ANTICIPATED CONVECTION AND SPARSER COVERAGE.
NAM AND GFS MOS GUIDANCE HAVE SLIGHT CHANCE FOR OVERNIGHT POPS.
CONSIDERING OTHER GUIDANCE ON HAND AND GENERAL UNCERTAINTY WILL
KEEP IN SLIGHT CHANCE TO CHANCE POPS FOR THE OVERNIGHT PERIOD.
BUFKIT AND OTHER DATA SHOW BETTER INSTABILITY SHOWING UP THIS
EVENING AND OVERNIGHT SO MAKING CHARACTER OF PRECIP MORE
CONVECTIVE IN NATURE AND WILL INCLUDE SLIGHT CHANCE FOR THUNDER.
THE HRRR HAS BEEN VERY HELPFUL TODAY IN DEPICTING COVERAGE AND
TRENDS SO WILL CONTINUE TO LEAN ON ITS GUIDANCE FOR THE NEAR TERM.
THIS MODEL HAS ISOLATED TO SCATTERED SHOWERS FOR THE REMAINDER OF
THE AFTERNOON WITH PERHAPS A MORE MODERATE LINE OF CONVECTION
MOVING THROUGH AROUND MIDNIGHT. EXTENSIVE CLOUD COVER AND WARM
FROPA WILL KEEP TEMPS OVERNIGHT ON THE MODERATE SIDE...IN VARIOUS
SHADES OF THE 60S. THIS IS NOT MUCH DIFFERENT THAN TODAYS DAYTIME
READINGS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...ALTHOUGH FRONT WILL BE DRAPED FROM WEST
TO EAST ACROSS THE CAROLINAS...POSSIBLY BISECTING THE LOCAL
FORECAST AREA EARLY SUNDAY...SHORTWAVE WILL BE EXITING OFF INTO
THE OFF SHORE WATERS WITH A STRONG WESTERLY DOWNSLOPE FLOW IN
PLACE ABOVE THE SURFACE. WARM SECTOR TO THE SOUTH OF FRONT WILL BE
IN SOUTHWEST FLOW AT THE SFC WHILE LIGHT NORTHERLY WINDS WILL
PREVAIL TO THE NORTH OF THE BOUNDARY. LOW CLOUDS SHOULD BE PRESENT
TO THE NORTH OF THE BOUNDARY WHERE BETTER ISENTROPIC LIFT AND MORE
STABLE COOLER AIR WILL BE PRESENT. TO THE SOUTH OF THE BOUNDARY
SHOULD SEE DRIER AIR PRESENT AND MORE IN THE WAY OF SUNSHINE.
MODELS HAVE BEEN FAIRLY CONSISTENT WITH KEEPING NORTHERN HALF OF
FORECAST AREA CLOUDIER WHILE MOST OF SOUTH CAROLINA WILL SEE FAIR
AMOUNT OF SUNSHINE. LOOKING AT MOISTURE PROFILES AND SOUNDING
DATA...SHALLOW MOISTURE LOCKED IN EARLY SUNDAY SHOULD BREAK UP AS
MID CLOUDS MOVE IN. TRICKY FORECAST IN TERMS OF CLOUDS AND TEMPS
AS FRONT SHOULD BISECT PORTION OF THE FORECAST AREA WITH WARMER
AIR AND MORE SUNSHINE TO THE SOUTH AND CLOUDIER AND COOLER AIR TO
THE NORTH. THIS FRONT WILL ALSO GET PUSHED SOUTH FAIRLY QUICKLY ON
SUNDAY AS SHORTWAVE DIGS DOWN PUSHING COLD FRONT SOUTH. LATEST
MODELS KEEP BEST SHORTWAVE ENERGY TO THE NORTH OF FORECAST AREA.
EXPECT BEST CHC OF PCP AS FRONT DROPS SOUTH THROUGH THE DAY ON
SUNDAY...BUT LIMITED MOISTURE WILL BE PRESENT WITH PCP WATER
VALUES ONLY REACHING JUST OVER AN INCH ALONG BOUNDARY BY SUN EVE
AND THEREFORE DO NOT EXPECT MUCH IN THE WAY OF QPF. CAN NOT RULE
OUT A POSSIBLE HEAVIER SHOWER CLOSER TO THE SHORE WHERE BETTER
MOISTURE COMBINES WITH ENHANCED CONVERGENCE ALONG SEA BREEZE
BOUNDARY. TEMPS SHOULD REACH INTO THE 80S SOUTH OF FRONT AND
REMAIN CLOSER TO 70 NORTH OF THE FRONT. GFS REMAINS SLOWER TO DROP
FRONT SOUTH AND THEREFORE IS MORE OPTIMISTIC IN TERMS OF SUNSHINE
AND WARMER TEMPS ACROSS A GOOD PORTION OF THE AREA SUNDAY WHILE
THE NAM KEEPS CLOUDS AND BRINGS COOLER AIR SOUTH QUICKER LEAVING
COOLER TEMPS OVER MUCH OF AREA EXCEPT EXTREME SOUTHERN PORTION.
ONCE FRONT DROPS SOUTH...EXPECT DRY AND COOLER AIR TO ADVECT IN
AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH SUN NIGHT INTO MONDAY.
850 TEMPS DROP FROM 14C SUN MORNING DOWN TO 3 C BY MON NIGHT AS
HEIGHTS LOWER AS DEEP TROUGH PASSES ACROSS THE EAST COAST. EXPECT
TEMPS CLOSER TO 70 ON MONDAY AS SUNSHINE TRIES TO OFFSET THE CAA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 330 AM SATURDAY...A DEEP N-NW FLOW WILL REMAIN IN PLACE
THROUGH TUES AS WEAK HIGH PRESSURE HOLDS ON. BY TUES NIGHT INTO
WED A SOUTHERN STREAM LOW MOVES ACROSS THE SOUTHEAST SPREADING
CLOUDS AND PCP NORTH. BEST CHC OF PCP SHOULD COME WED IN INCREASED
LIFT AND MOISTURE. THIS LOW WILL TRACK OFF THE COAST ON THURS WITH
LINGERING CLOUDS AND PCP UNTIL DRY HIGH PRESSURE BUILDS DOWN THURS
NIGHT INTO FRI...LEAVING SUNNY AND MORE SEASONABLE WEATHER HEADING
INTO NEXT WEEKEND. TEMPS REMAIN BELOW NORMAL THROUGH MOST OF THE
PERIOD WITH WARMER AND MOISTER AIR MASS RETURNING ON THURS AS AN ON
SHORE FLOW MAY COME AROUND TO THE SOUTH AS LOW MOVES SOUTH OF
AREA.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 18Z...LIGHT RAIN HAS SPREAD OVER MOST OF THE CWA. THE PRECIP
IS STRATIFORM WITH NO CONVECTION IN THE REGION AT THIS TIME. SOME
ISOLATED CONVECTION IS POSSIBLE OVER OUR EXTREME SOUTHERN
BOUNDARIES...WITH MAINLY MVFR CEILINGS LATER THIS AFTERNOON AS THE
PRECIPITATION INDUCED CEILINGS LOWER. TONIGHT...MOST OF THE RAIN
WILL END... WITH LOWER CEILINGS EXPECTED. RATHER LOW CONFIDENCE ON
CEILINGS AND PRECIP FOR SUNDAY AS FRONTAL BOUNDARY REMAINS NEARLY ON
TOP OF US. SHOULD SEE A GOOD WESTERLY WIND TOWARD THE END OF THE
FORECAST PERIOD WITH LOW PRESSURE CENTERED JUST TO OUR NORTH.
EXTENDED OUTLOOK...VFR MONDAY AND TUESDAY. SHOWERS POSSIBLE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 2 PM SATURDAY...SOUTH WINDS THIS AFTERNOON WILL BECOME SW
TONIGHT AS A WARM FRONT MOVES NORTH ACROSS THE WATERS. WINDS WILL
STAY IN THE GENERAL 10 TO 15 KT RANGE WITH 2 TO 4 FT OF SEAS FOR
MOST OF THE PERIOD. HOWEVER...THERE MAY BE A BRIEF PERIOD OF
HIGHER WINDS AND SEAS TONIGHT AS THE WARM FRONT APPROACHES THE
WATERS. IF SO...EXERCISE CAUTION HEADLINES MAY BE NEEDED.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...FRONT WILL BE BISECTING THE COASTAL
WATERS FROM WEST TO EAST EARLY SUNDAY. SW WINDS ON SOUTH SIDE OF
FRONT WILL PUSH SEAS UP TO 3 TO 5 FT THROUGH MUCH OF SUNDAY BEFORE
SHIFTING AROUND TO THE NW AND NORTH AS LOW PRESSURE MOVES OFF TO
THE EAST AND COLD FRONT MOVES SOUTH THROUGH THE WATERS LATER IN
THE DAY. THE LATEST WNA KEEPS SEAS JUST BELOW SCA THRESHOLDS WITH
PEAK IN SEAS SUN AFTN INTO EARLY EVE. COULD SEE A BRIEF NORTHERLY
SURGE LATE SUN AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH KEEPING
SEAS UP THROUGH SUN NIGHT BUT OVERALL EXPECT NORTHERLY FLOW TO
DIMINISH THROUGH MONDAY....LEAVING SEAS DOWN TO 2 TO 4 FT. WILL
SEE ANOTHER BRIEF SURGE IN N-NW WINDS MON NIGHT WITH A MINOR SPIKE
IN SEAS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY... NORTHERLY FLOW WILL PERSIST THROUGH
TUESDAY BEFORE WINDS BEGIN TO VEER AROUND TO THE EAST BY TUES
NIGHT AS LOW PRESSURE BEGINS TO MIGRATE EAST FROM THE GULF COAST.
EXPECT SEAS TO REMAIN 2 TO 4 FT THROUGH TUES...WITH A SLIGHT ON
SHORE PUSH BY TUES NIGHT. WINDS SHOULD SHIFT AROUND TO THE SE-S
ON WED AS LOW MOVES ACROSS THE SOUTHEAST POSSIBLY PASSING DIRECTLY
ACROSS LOCAL WATERS WED NIGHT. SEAS WILL RISE TO 3 TO 5 FT LATE
WED IN INCREASED ON SHORE TO SOUTHERLY PUSH AS LOW MOVES BY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...REK
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...REK/DL
MARINE...REK/MJC/RGZ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1255 PM CDT SAT APR 25 2015
.UPDATE...
ISSUED AT 1255 PM CDT SAT APR 25 2015
MAIN ISSUE FOR THE EARLY AFTERNOON UPDATE WAS TEMPERATURES AND SKY
COVER. LOWERED TEMPERATURES ACROSS THE WEST AND SOUTH. LOOKS LIKE
WARMEST AREA COULD BE THE NORTH CENTRAL WHERE SKIES HAVE CLEARED
AND COULD GET A BIT OF AFTERNOON SUNSHINE BEFORE CLOUDING UP
LATER. LOWERED SKY COVER OVER THE NORTH CENTRAL THIS AFTERNOON.
WILL KEEP THE MENTION OF ISOLATED THUNDER FAR WEST THIS AFTERNOON
BUT THINK ITS A LONG SHOT LATEST WRF SHOWS SHOWERS...MAYBE SOME
THUNDER DISSIPATING AS PRECIPITATION MOVES INTO FAR WESTERN NORTH
DAKOTA 23-02 UTC.
UPDATE ISSUED AT 1023 AM CDT SAT APR 25 2015
SOUTHEAST FLOW CONTINUES OVER MOST OF THE FORECAST AREA INTO AN
LOW PRESSURE TROUGH SITUATED OVER EASTERN MONTANA. LATEST
MESOSCALE MODELS AND NEW NAM INDICATE LOW LEVEL MOISTURE HANGING
AROUND TODAY...WITH SHOWERS SLOW TO REACH THE WESTERN BORDER. WILL
BUMP UP SKY COVER AND PUSH BACK POPS CHANCES IN THE WEST UNTIL 21
UTC. LOWERED TEMPERATURES JUST A BIT. MAY NEED TO RE-VISIT
TEMPERATURES WITH THE EARLY AFTERNOON UPDATE.
UPDATE
ISSUED AT 627 AM CDT SAT APR 25 2015
NO MAJOR EDITS TO THE GOING FORECAST. STRATUS CONTINUES TO EXPAND
ACROSS THE REGION WITH A MOIST/EASTERLY UPSLOPE FLOW. MODELS TRY
TO ERODE THE CLOUDS AS WE PROGRESS THROUGH THE MORNING...BUT
CLOUDY CONDITIONS THROUGHOUT THE DAY SEEM LIKELY. AREAS OF FOG
PERSIST...WITH LOCALLY DENSE FOG SOUTHWEST WHERE A SPECIAL WEATHER
STATEMENT IS IN EFFECT THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT APR 25 2015
THE MAIN FOCUS FOR THE SHORT TERM THIS MORNING IS LOW CLOUD COVER
AND FOG...LEADING TO AVIATION ISSUES. THE FOCUS THEN TURNS TO
PRECIPITATION ACROSS THE WEST THIS AFTERNOON/EVENING.
EASTERLY UPSLOPE SURFACE FLOW IS BRINGING IN LOW LEVEL MOISTURE
AND RESULTING IN VERY LOW STRATUS AND FOG DEVELOPMENT. CURRENTLY
ABOUT 2/3 OF NORTH DAKOTA IS COVERED. THE STRATUS DECK SHOULD MAKE
IT ALL THE WAY TO MONTANA THIS MORNING. THE LATEST HRRR AND RAP
INDICATE CLOUD COVER AND FOG WILL CONTINUE THROUGH THE EARLY
AFTERNOON HOURS. AS FORCING BECOMES FOCUSED ACROSS WESTERN NORTH
DAKOTA THIS AFTERNOON AND MID-LEVEL FLOW INCREASES AHEAD OF THE
AN UPPER-LEVEL SHORTWAVE TROUGH...CLOUD CEILINGS SHOULD LIFT AND
BEGIN TO SCATTER OUT.
THE LATEST TREND IN THE MODELS IS TO DELAY PRECIPITATION FROM
ENTERING NORTH DAKOTA UNTIL LATE THIS AFTERNOON. CONTINUED THE
TRENDS FROM EARLIER FORECAST UPDATES AND PUSHED PRECIP CHANCES
EVEN FURTHER WESTWARD AND DELAYED ONSET. HOWEVER...UNLIKE
PREVIOUSLY THOUGHT IT DOES APPEAR THAT THERE COULD BE A FEW
ISOLATED THUNDERSTORMS. THE 00 AND 06 UTC MODELS BRING AN AXIS OF
INSTABILITY ACROSS WESTERN NORTH DAKOTA AS FAR NORTH AS THE
CANADIAN BOARDER. AS SUCH INCLUDED THE MENTION OF THUNDERSTORMS
IN THE FORECAST FOR WESTERN NORTH DAKOTA LATE THIS AFTERNOON.
TONIGHT A BAND OF RAIN WILL SLOWLY MOVE ACROSS WESTERN NORTH
DAKOTA...INTO CENTRAL NORTH DAKOTA BY TOMORROW MORNING. WITH VERY
LITTLE PROGRESSION OF THE MAIN FEATURES (SURFACE LOW...LONG WAVE
TROUGH OUT WEST...ETC.) EXPECTED OVER THE NEXT DAY...SEVERAL HOURS
OF MUCH NEED LIGHT RAIN APPEARS LIKELY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT APR 25 2015
AN UNSETTLED WEATHER PATTERN SLOWLY SPREADING FROM WEST TO EAST
SATURDAY THROUGH MONDAY HIGHLIGHTS THE EARLY PORTION OF THE
EXTENDED PERIOD. A SPLIT FLOW REGIME WITH TWO SIGNIFICANT
SHORTWAVE TROUGHS WILL AFFECT THE NORTHERN PLAINS.
FOR SUNDAY-SUNDAY NIGHT...LOW LEVEL MOISTURE WILL CONTINUE TO
SPREAD ACROSS THE REGION. EMBEDDED S/WV IMPULSE ORIGINATING FROM
A DEEP UPPER LOW OVER THE SOUTHERN ROCKIES WILL ROTATE NORTH
ACROSS THE CENTRAL HIGH PLAINS...THEN GETS CAUGHT UP IN THE
NORTHERN STREAM AND SLOWLY MOVES ACROSS MY WEST LIFTING NORTHEAST
BY MONDAY 12Z. BEST VERTICAL MOTION WILL OCCUR ALONG A QUASI-
STATIONARY FRONT INITIALLY ACROSS WESTERN NORTH DAKOTA...AND WILL
MAINTAIN ELEVATED POPS THERE SUNDAY DAYTIME. FRONT STARTS TO
ORIENTATE SOUTHWEST TO NORTHEAST...ALLOWING SHOWERS TO CONTINUE
WEST AND SPREAD INTO THE NORTH CENTRAL SUNDAY NIGHT. SHOULD BE
MAINLY DRY FOR THIS PERIOD ACROSS MY SOUTHEAST.
FOR EARLY MONDAY THROUGH MONDAY NIGHT...NORTHERN STREAM TROUGH
APPROACHES AND PUSHES EAST ACROSS THE STATE...RE-ENERGIZING THE
SURFACE COLD FRONT AND PRODUCING ANOTHER ROUND OF SHOWERS
SPREADING FROM WEST TO EAST. IT WILL BE DURING THIS TIME PERIOD
THAT THE HIGHEST PROBABILITY FOR RAIN WILL OCCUR IN CENTRAL NORTH
DAKOTA.
TOTAL RAINFALL AMOUNTS STILL LOOK LIKE A HALF INCH TO ONE INCH
WEST WITH AROUND A QUARTER OF AN INCH CENTRAL THROUGH MONDAY
NIGHT.
TUESDAY THROUGH FRIDAY...MAINLY DRY AND WARM CONDITIONS AS A
MID/UPPER LEVEL RIDGE SLOWLY MOVES EAST ACROSS THE ROCKIES AND
INTO THE GREAT PLAINS. AFTERNOON HIGHS WEDNESDAY AND THURSDAY
WILL MOSTLY BE IN THE 70S...WITH POSSIBLY SOME LOWER 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1255 PM CDT SAT APR 25 2015
A MOIST SOUTHEAST FLOW WILL CONTINUE OVER THE FORECAST AREA
THROUGH THIS EVENING OVER WESTERN NORTH DAKOTA...THEN BECOMING
LIGHT AND VARIABLE AS A COLD FRONT MOVES INTO WESTERN NORTH DAKOTA
AND BECOMES NEARLY STATIONARY. SOUTHEAST FLOW WILL CONTINUE OVER
CENTRAL NORTH DAKOTA THROUGH 18Z SUNDAY. MVFR-IFR CEILINGS ARE
EXPECTED ACROSS THE FORECAST AREA THROUGH 18Z SUNDAY. SHOWERS WILL
REMAIN OVER KDIK-KISN THROUGH TONIGHT...THEN SPREAD EAST TO KMOT
AND PROBABLY JUST WEST AND NORTH OF KBIS 12-18Z SUNDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...NH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1210 PM CDT SAT APR 25 2015
.UPDATE...
ISSUED AT 927 AM CDT SAT APR 25 2015
LOOKING AT THE TRENDS IN THE 25.12Z RAP AND 25.13Z HRRR IT APPEARS
ANY CHANCES FOR RAIN TODAY WILL BE LIMITED TO THE VERY SOUTHERN
PARTS OF THE AREA. THE RAP INDICATES THERE IS A WEAK SHORT WAVE
TROUGH ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW THAT COULD
PRODUCE SOME WEAK FORCING OVER THE AREA BEFORE SHIFTING OFF TO THE
EAST DURING THE MID AND LATE AFTERNOON HOURS. SOME WEAK
FRONTOGENESIS IN THE 850-700 MB LAYER COULD ALSO ROTATE BACK NORTH
INTO THE AREA AROUND 18Z. TRIMMED THE NORTHERN EXTENT OF THE RAIN
CHANCES FOR THE REST OF THE DAY TO CONFINE THEM TO THE FAR
SOUTHERN AREAS. ALSO LOWERED THEM DOWN FROM THE 60 TO 70 PERCENTS
TO ABOUT 30 OR 40 PERCENT. THE RAP SHOWS ALL THE CAPE REMAINING
WELL TO THE SOUTH WITH NO ELEVATED CAPE IN EITHER THE KDBQ OR KBLR
FORECAST SOUNDINGS SO HAVE DROPPED THE THUNDER MENTION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT SAT APR 25 2015
FORECAST FOCUS IN THE SHORT TERM IS THE RAIN THREAT TODAY. CLOSED
CIRCULATION SPINNING THROUGH KS EARLY THIS MORNING...HEADING EAST
AND WEAKENING THROUGH THE DAY TODAY. DEFORMATION AND FRONTOGENETIC
FOCUS ON THE NORTHERN EDGE OF THIS SYSTEM WILL SPREAD RAIN AND
EMBEDDED THUNDERSTORMS ACROSS IA AND NORTHERN IL. MAIN DILEMMA IS
HOW FAR NORTH RAIN WILL GET. VARIOUS MODEL SOLUTIONS OVER THE PAST
SEVERAL DAYS HAD BEEN SUGGESTING RAIN WOULD SPREAD NORTH AS FAR
AS THE I-90 CORRIDOR. BUT THE LAST FEW RUNS HAVE NOW SHIFTED THAT
FOCUS FURTHER SOUTH. LOOKING AT THE FORCING AND THE INFLUX OF MORE
DRY LOW LEVEL AIR ON EAST/NORTHEAST WINDS SUPPORT A TIGHTER
RAIN/NO-RAIN GRADIENT AND THE SOUTHWARD SHIFT. THIS TREND IS
ALREADY BORNE OUT LOOKING AT OVERNIGHT RADAR LOOPS SHOWING THE
DIMINISHING TREND. SO MOVED THE FORECAST IN THIS DIRECTION FOR
TODAY. RAIN THREAT WILL END BY SUNSET AS HIGH PRESSURE OVER MB/ONT
BUILDS SOUTHWARD INTO THE REGION. AIRMASS DRIES AND BOUNDARY LAYER
TEMPERATURES TUMBLE. A CHILLY NIGHT IS ON TAP...ESPECIALLY OVER
OUR TYPICAL COOL AREAS OF CENTRAL WI.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT APR 25 2015
LOOKING INTO THE LONGER TERM...UPPER FLOW PATTERN REMAINS BLOCKED
THANKS TO THE EAST COAST CLOSED LOW WHICH PERSISTS INTO AT LEAST
TUESDAY. THIS KEEPS SURFACE HIGH PRESSURE AND DRY EASTERLY FLOW
POURING INTO THE AREA. A WEAK SHORT WAVE TROUGH DROPS INTO THE
BACK SIDE OF THE UPPER LOW LATE ON TUESDAY. THIS COULD BRING A FEW
LIGHT SHOWERS TO PARTS OF THE AREA...BUT WITH A VERY DRY
ATMOSPHERE THE CHANCES WILL BE QUITE LOW. THE PATTERN TRANSITIONS
TO MORE OF AN OMEGA LOOK BY LATE IN THE WEEK...PUTTING THE AREA
MORE IN THE UPPER RIDGE. THUS...A WARMING TREND IS ON TAP WITH
TEMPERATURES BACK ABOVE NORMAL. THE NEXT SIGNIFICANT CHANCE FOR
ANY RAINFALL LOOKS TO BE NEXT WEEKEND AS THE PERSISTENT SOUTHERLY
FLOW FINALLY GETS ENOUGH MOISTURE INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1210 PM CDT SAT APR 25 2015
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. HIGH PRESSURE OVER
ONTARIO WILL REMAIN NEARLY STATIONARY INTO SUNDAY AFTERNOON BUT
BECOME STRONGER ENABLING THE RIDGE AXIS TO EXTEND OVER THE AREA.
THE HIGH WILL CONTINUE TO BRING IN DRIER AIR WHICH WILL ALLOW THE
CLOUDS TO SCATTER OUT THROUGH THE AFTERNOON AND BECOME CLEAR EARLY
THIS EVENING. THE EAST WINDS WILL DROP TO LESS THAN 10 KNOTS AS
THE RIDGE AXIS STRENGTHENS AND REMAIN LIGHT THROUGH SUNDAY
MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...04
SHORT TERM...MW
LONG TERM...MW
AVIATION...04