Area Forecast Discussion
Issued by NWS Hastings, NE

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000
FXUS63 KGID 102356
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
656 PM CDT THU JUL 10 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 423 PM CDT THU JUL 10 2014

PRIMARY FORECAST CONCERNS LIE WITH THUNDERSTORM CHANCES
TONIGHT...THEN AGAIN LATE TOMORROW AFTERNOON.

QUIET CONDITIONS IN PLACE ACROSS THE CWA TODAY...WHICH REMAINS UNDER
THE INFLUENCE OF NORTHWESTERLY FLOW IN THE UPPER LEVELS THANKS TO
HIGH PRESSURE ANCHORED ROUGHLY OVER NM/CO...AND A BROAD TROUGH
WORKING ITS WAY TOWARD THE EAST COAST. THE NRN HALF OF THE CWA HAS
BEEN UNDER A LOW LEVEL CU FIELD MUCH OF THE DAY...BRINGING
PARTLY/MOSTLY CLOUDY SKIES...WHILE THE SOUTH HAS SEEN PLENTY OF SUN.
SOUTHERLY WINDS HAVE BEEN IN PLACE THROUGH THE DAY...AS HIGH
PRESSURE SITS OVER THE GREAT LAKES AND A TROUGH OF LOW PRESSURE LIES
ALONG THE HIGH PLAINS. 3 PM TEMPS RANGE FROM THE UPPER 70S IN THE
NORTH TO UPPER 80S IN THE SOUTH.

SEEING SOME THUNDERSTORM ACTIVITY DEVELOPING OVER THE PANHANDLE OF
NEBRASKA THIS AFTERNOON...AND SOME QUESTION LINGERS EVEN NOW HOW
MUCH OF THE CWA WILL BE AFFECTED BY THUNDERSTORMS LATER THIS
EVENING/TONIGHT AS A WEAK UPPER LEVEL DISTURBANCE SLIDES EAST.
OUTSIDE OF THE GFS...THE 12Z RUN OF MODELS AND RECENT RUNS OF THE
HRRR/RAP WERE IN PRETTY GOOD AGREEMENT SHOWING THE BETTER CHANCES
SLIDING TO OUR NORTH...PERHAPS CLIPPING OUR FAR NRN COUNTIES
OVERNIGHT. THEY SHOWED A CAPPED ATMOSPHERE WITH 700MB TEMPS IN THE
12-15C RANGE...AND BETTER LIFT/CONVERGENCE ALONG THE NOSE OF AN
INCREASING SRLY LOW LEVEL JET ALONG/JUST NORTH OF OUR NRN COUNTIES.
DID NOT COMPLETELY REMOVE POPS TONIGHT...BUT DID SLOW DOWN THE ONSET
AND TRIMMED THE SOUTHERN AREA SO THAT LOCATIONS SOUTH OF HIGHWAY 6
ARE DRY THROUGH THE OVERNIGHT HOURS. SHOULD THUNDERSTORMS AFFECT THE
CWA...HAIL NEAR THE SIZE OF NICKELS AND GUSTY WINDS WILL BE
POSSIBLE...THOUGH MODELS SHOW DIMINISHING MUCAPE VALUES
OVERNIGHT...POTENTIALLY COULD HAVE MODEST VALUES IN PLACE...WITH
DEEP LAYER SHEAR VALUES ARND 25-30KTS. WILL SEE IF THE CAPPING HOLDS
AND WHERE THE PLACEMENT OF THAT BETTER LLJ LIFTING ENDS UP.

KEPT THE MORNING HOURS DRY ON FRIDAY...THOUGH THERE IS SOME HINT
THAT THERE COULD BE SOME LINGERING ACTIVITY FOR A FEW HOURS. WOULD
LIKE TO SEE HOW THINGS ACTUALLY EVOLVE BEFORE INSERTING ADDITIONAL
POPS. OUTSIDE OF THAT...EXPECTING DRY CONDITIONS INTO THE AFTERNOON
HOURS AHEAD OF THE NEXT DISTURBANCE THAT WILL BE AFFECTING THE
REGION. AT THE SURFACE...LOW PRESSURE SETS UP OVER THE NRN KS/CO
BORDER BY MID AFTERNOON...WITH MODELS IN GOOD AGREEMENT SHOWING A
WARM FRONT EXTENDING E/NE THROUGH THE CENTRAL/NRN PORTIONS OF THE
CWA. INHERITED SOME LOW POPS DURING THE LATE AFTERNOON HOURS...AND
KEPT THEM GOING IN THE WEST WHICH WOULD BE STARTING TO COME UNDER
THE INFLUENCE OF INCREASING LIFT...BUT CONFIDENCE IN ANYTHING
OCCURRING PRIOR TO 00Z IS NOT HIGH AS MODELS CONTINUE TO SHOW A
HEALTHY CAP IN PLACE OVER THE CWA. EXPECTING GUSTY SOUTH WINDS SOUTH
OF THE FRONT WITH HIGHS CLIMBING WELL INTO THE 90S /100 DEGREES
POSSIBLE IN NC KS...WITH MORE EASTERLY WINDS NORTH OF THE FRONT AND
TEMPS STRUGGLING TO GET MUCH ABOVE THE UPPER 80S/NEAR 90. JUST A
LITTLE UNCERTAINTY ON WHERE EXACTLY THAT FRONT WILL SET UP.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 PM CDT THU JUL 10 2014

STARTING WITH THIS BIG-PICTURE OF THIS 6-DAY PERIOD...THERE ARE
REALLY TWO DISTINCT WEATHER REGIMES HERE. THE FIRST REGIME...WHICH
GENERALLY COVERS THE FRIDAY NIGHT THROUGH MONDAY TIME
FRAME...INVOLVES A CONTINUATION OF SEASONABLY WARM TEMPERATURES
AND VARIOUS THUNDERSTORM CHANCES...ALONG WITH WHAT COULD VERY WELL
BE A FEW MORE CHANCES FOR SEVERE STORMS. THE SECOND REGIME...WHICH
LARGELY DEFINES MONDAY NIGHT THROUGH THURSDAY...INVOLVES A RETURN
TO PREDOMINANTLY DRY AND COOLER WEATHER ALONG WITH LOWER
DEWPOINT/HUMIDITY LEVELS...INCLUDING A FEW DAYS CURRENTLY CENTERED
TUESDAY-WEDNESDAY TIME FRAME DURING WHICH HIGH TEMPERATURES ARE
ONLY FORECAST TO REACH THE 70S ACROSS MOST ALL OF THE CWA OR
ROUGHLY 10-15 DEGREES BELOW NORMAL/AVERAGE FOR MID-JULY.
OFFICIALLY...HAVE CLOSELY FOLLOWED THE DEFAULT MULTI-MODEL BLEND
WE USE TO POPULATE THE DAY 4-7 TIME FRAME TO LINGER SOME SMALL
20-30 POPS WITHIN ROUGHLY THE SOUTHWEST HALF OF THE CWA FROM
MONDAY NIGHT- TUESDAY...BUT EVEN THESE POPS COULD BE ON SHAKY
GROUND...AND WE ALREADY HAVE THE TUESDAY NIGHT-THURSDAY TIME FRAME
VOID OF ANY MENTIONABLE PRECIP CHANCES (AT LEAST FOR NOW).

THE MAJOR FEATURE THAT WILL DEFINE THE TRANSITION BETWEEN THESE
TWO MAIN AFOREMENTIONED WEATHER REGIMES WILL BE THE PASSAGE OF A
RATHER DEEP/COOL LARGE SCALE TROUGH FOR THIS TIME OF YEAR THAT
WILL DIVE SOUTH-SOUTHEASTWARD FROM SOUTH CENTRAL CANADA THIS
WEEKEND INTO THE GREAT LAKES/NORTHEASTERN CONUS THROUGH THE
EARLY-MID PART OF NEXT WEEK. ALTHOUGH THE LOCAL PLAINS AREA WILL
RESIDE ALONG THE SOUTHWESTERN PERIPHERY OF SIGNIFICANT INFLUENCE
FROM THIS MAJOR TROUGH...THE EFFECTS OF THE FAIRLY STRONG COLD
FRONT SLATED TO PASS THROUGH DURING THE MONDAY-MONDAY NIGHT TIME
FRAME WILL STILL BE QUITE NOTICEABLE.

GOING INTO SOME BRIEF COMMENTS ON INDIVIDUAL 12-24 HOUR PERIODS:

FRIDAY EVENING/NIGHT...WILL HAVE TO WATCH FOR A SLIGHT RISK OF
SEVERE STORMS MAINLY WITHIN THE NORTHERN 1/2 TO 1/3 OF THE
CWA...ALTHOUGH SPC HAS THE OFFICIAL DAY 2 SLIGHT RISK AREA ALL THE
WAY DOWN TO THE STATE LINE AREA. WITH THE CWA LYING NEAR THE NORTHERN
PERIPHERY OF THE SUBTROPICAL RIDGE BUILDING IN FROM THE
SOUTH...EXPECT SOUTHERN ZONES TO BE MORE CAPPED WHILE FAR NORTHERN
ZONES NEAREST THE PRIMARY WEST-EAST SURFACE FRONT WILL BE MORE
FAVORED FOR STORMS...AND THUS HAVE POPS RANGING FROM 20S FAR SOUTH
TO 40S NORTH. ALTHOUGH MESOSCALE DETAILS ARE FAR FROM
CERTAIN...THE COMBO OF DECENT INSTABILITY AND DEEP-LAYER SHEAR
COULD SUPPORT A FEW SUPERCELLS AND/OR SEVERE QUASI-LINEAR
STRUCTURES IN THE NORTHERN CWA.

SATURDAY DAYTIME-SATURDAY NIGHT...THE INITIAL...WEAK COLD FRONTAL
PUSH THIS WEEKEND WORKS SOUTHWARD ACROSS THE AREA...AS DEEP LAYER
SHEAR STRENGTHENS A BIT AS STRONGER UPPER LEVEL WINDS WORK
SOUTHWARD INTO THE AREA. CONFIDENCE IN THE DETAILS REMAINS QUITE
LOW...BUT 20-30 POPS CONTINUE AREA-WIDE DURING THIS TIME
FRAME...WITH EVEN SOUTHERN ZONES COMING MORE INTO PLAY AS THE
SURFACE FRONT SETTLES FARTHER SOUTH. AGAIN COULD SEE A SEVERE
RISK...AND WOULD NOT BE SURPRISED TO SEE AT LEAST PORTIONS OF THE
CWA UPGRADED TO A FORMAL SLIGHT RISK BY SPC ON UPCOMING DAY 2/DAY
1 OUTLOOKS. HIGH TEMPS AIMED FROM MID 80S NORTH-MID 90S
SOUTH...AND A FEW FAR SOUTHERN AREAS COULD FLIRT WITH 100 DEGREE
HEAT INDEX VALUES BUT ARE EXPECTED TO FALL JUST SHORT.

SUNDAY DAYTIME-SUNDAY NIGHT...VARIOUS DISTURBANCES RIPPLE THROUGH
THE INCREASINGLY-NORTHWESTERLY FLOW...KEEPING SLIGHT POPS IN PLACE
FOR ALL AREAS DURING THE DAY AND IN WESTERN ZONES SUNDAY NIGHT.
PER THE GFS...THESE SUNDAY NIGHT POPS MAY NEED EXPANDED TO COVER
MORE OF THE AREA. AGAIN WILL HAVE TO MONITOR FOR A SLIGHT RISK OF
SEVERE STORMS IN SOME AREAS. HIGH TEMPS AIMED MID 80S NORTH-LOW
90S SOUTH.

MONDAY DAYTIME-MONDAY NIGHT...COOLER AND DRIER AIR RUSHES IN
BEHIND THE PRIMARY STRONG COLD FRONT...BUT WITH 30 POPS ALL AREAS
DURING THE DAY ASSOCIATED WITH FRONTAL PASSAGE...AND 20S IN
SOUTHWEST AREAS AT NIGHT. HIGHS UPPER 70S FAR NORTH-NEAR 90 FAR
SOUTH.

TUESDAY DAYTIME-TUESDAY NIGHT...DESPITE THE POPS IN SOUTHWEST
ZONES DURING THE DAY...THESE 24 HOURS ARE PROBABLY TRENDING DRY
ALTOGETHER AS STRONG/SEASONABLY COOL HIGH PRESSURE MOVES IN. HIGHS
ONLY MID-UPPER 70S.

WEDNESDAY DAYTIME-WEDNESDAY NIGHT...CONTINUED DRY ALTHOUGH MAY
HAVE TO WATCH THE FAR SOUTHWESTERN CWA FOR SOME POSSIBLE EVENTUAL
INCLUSION OF SLIGHT POPS. HIGHS MID-70S TO NEAR 80.

THURSDAY DAYTIME...STILL LOOKING DRY FOR NOW...AND SLIGHTLY WARMER
AS BREEZES BECOME MORE ESTABLISHED FROM THE SOUTH AGAIN. HIGHS
AIMED LOW-MID 80S WHICH IS STILL 5+ DEGREE BELOW NORMAL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 656 PM CDT THU JUL 10 2014

VFR CONDITIONS TO START THE TAF PERIOD...WITH MVFR CONDITIONS
POSSIBLE 08-13Z...FOLLOWED BY VFR CONDITIONS 13Z ONWARD. LOW LEVEL
WIND SHEAR WILL ALSO BE POSSIBLE 08-13Z.

OCCASIONAL CLOUD COVER NEAR 15000FT AGL WILL BE POSSIBLE AT BOTH
SITES THROUGH MUCH OF THE TAF PERIOD. A LOWER TROPOSPHERIC WIND
FIELD...PERSISTING FROM THE SOUTHEAST...WILL RESULT IN MOISTURE
FLUX ACROSS THE REGION TONIGHT THUS PRESENTING THE POSSIBILITY OF
FOG AND/OR DRIZZLE TOWARDS SUNRISE FRIDAY. MULTIPLE SETS OF
GUIDANCE SUGGEST MVFR CONDITIONS WILL BE REALIZED AND AS A
RESULT...WENT AHEAD WITH A VISIBILITY RESTRICTION OF 5SM IN BR AND
-DZ 08-13Z. THE AXIS OF A ~40KT LOWER TROPOSPHERIC JET AXIS...JUST
ABOVE THE BOUNDARY LAYER...MAY ALSO PROMOTE ENOUGH THERMAL
ADVECTION FOR STRATUS FORMATION...WITH SOME SETS OF GUIDANCE
SUGGESTING A CEILING NEAR 2000FT AGL WILL RESULT. THE STRENGTH OF
THIS JET AXIS...AS WELL AS THE MAGNITUDE OF RESULTANT THERMAL
ADVECTION...IS SOMEWHAT QUESTIONABLE HOWEVER DUE TO SEVERAL
DIFFERING MODEL SOLUTIONS SO FOR NOW...WILL ONLY GO WITH A
SCATTERED DECK NEAR 2000FT AGL 08-13Z AND LET FUTURE SHIFTS ADJUST
THE TAFS AS NECESSARY. THE AFOREMENTIONED LOWER TROPOSPHERIC JET
AXIS MAY ALSO PROMOTE A PERIOD OF LOW LEVEL WIND SHEAR AT BOTH TAF
SITES. AGAIN...THE STRENGTH OF THIS JET AXIS IS SOMEWHAT
QUESTIONABLE...BUT JUST ENOUGH CONFIDENCE EXISTS TO GO AHEAD WITH
LOW LEVEL WIND SHEAR AT GRI AND EAR 08-13Z. FINALLY...THERE IS A
VERY LOW CHANCE FOR SHOWER AND THUNDERSTORM ACTIVITY TONIGHT AT
BOTH TAF SITES...BUT AT THIS TIME THE PROBABILITY OF SUCH ACTIVITY
BEING REALIZED IS TOO LOW FOR INCLUSION IN THE TAFS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...ADO
LONG TERM...PFANNKUCH
AVIATION...BRYANT



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