000
FXUS63 KGID 311728
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1228 PM CDT THU JUL 31 2014

.UPDATE...
ISSUED AT 653 AM CDT THU JUL 31 2014

THE HOURLY FCST HAS BEEN UPDATED THRU 2 PM. OTHER THAN SHORT-TERM
ADJUSTMENTS TO TEMPS/DWPTS/WINDS...THE MAIN CHANGE WAS TO REMOVE
POPS FOR MOST OF THE MORNING.

FCST IS EVOLVING AS ANTICIPATED. THICK CIRROSTRATUS IS MOVING THRU
WITH PATCHES OF BEEFY ALTOCU /ACCAS/ INDICATING THE MID-LVL
INSTABILITY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT THU JUL 31 2014

...AFTER ANOTHER PLEASANT STRETCH OF COOLER TEMPS WE RETURN TO
NORMAL TODAY AS WE CLOSE OUT A COOLER AND FAIRLY DRY JULY FOR
MOST OF THE REGION...

ALOFT: NO CHANGE. NW FLOW WILL CONT TO DOMINATE. THERE IS A VERY
SMALL TROF OVER SD /BEST SEEN AT 700 MB/. THIS TROF WILL CONT
DROPPING S...CROSSING NEB TODAY AND TONIGHT.

SURFACE: HIGH PRES CONTS TO ENCOMPASS MOST OF THE ERN USA.
EMBEDDED IN THIS HIGH WAS A VERY WEAK LOW OVER SD...ASSOCIATED
WITH THE MID-LVL TROF. THIS LOW WILL CONT MOVING S...CROSSING NEB
ALONG WITH ITS MID-LEVEL FORCING...TO BE LOCATED NEAR CONCORDIA KS
AT DAYBREAK TOMORROW.

LOOKING AT VIS SATELLITE AND RADAR LOOPS FROM WED AFTERNOON...A
FEW ISOLATED/SMALL SHWRS DEVELOPED AROUND THE SRN FRINGE OF THE SD
LOW. THERE WAS ONLY ONE CG LIGHTNING STRIKE. 00Z UNR/ABR SOUNDINGS
SHOW MOISTURE IS LACKING. THE OBSERVED ABR SOUNDING IS VERY
SIMILAR TO WHAT THE NAM BUFKIT SHOWED 24 HRS AGO...WITH
SBCAPE/MLCAPE ONLY 340 J/KG WITH A VERY THIN CAPE PROFILE. SO THE
SREF FCST OF 750-1000 J/KG LOOKS WAY OVERDONE. I ORIGINALLY WAS
NOT PLANNING ON PUTTING THUNDER IN THE FCST...BUT BETWEEN 1 AM-3
AM CLOUD TOPS HAVE BEEN COOLING OVER ERN SD WITH NEW SHWRS
FORMING. THERE HAVE BEEN A COUPLE STRIKES. SO THUNDER HAS BEEN
MAINTAINED FROM THE 4 PM FCST.

THE SAMPLE TOOL SHOWS CLOUD TOP TEMPS AROUND -30C AT 330 AM WHICH
TRANSLATES TO TOPS OF 27K FT. WEAK UPDRAFTS WILL BE THE LIMITER OF
LIGHTNING POTENTIAL.

THE FCST OF SHWRS/TSTMS WILL MAKE THE POTENTIAL SOUND WORSE THAN
IT REALLY IS. WOULD PREFER THE FCST WORDED AS SLIGHT CHANCE OF
SHWRS AND POSSIBLY A RUMBLE OF T. MITCHELL SD /MHE/ DID MEASURE
.03" BETWEEN 2-3 AM. IF ISOLATED SHWRS ARE DEVELOPING OVERNIGHT
THERE SHOULD BE NO PROBLEM POPPING A FEW WITH DAYTIME HEATING.

THE NAM CONTS THE LEADER ON THIS SHWR POTENTIAL BUT THE 00Z GEM/
GFS HAVE COME AROUND WITH THEIR QPF. THE 12Z/00Z EC RUNS DUMP
SOME LIGHT QPF AS WELL...BUT ONLY NE OF THE FCST AREA.

TODAY: LARGE PATCHES OF THICK CIRROSTRATUS WILL DEPART FROM W-E
THIS MORNING. DAYTIME HEATING WILL RESULT IN WIDESPREAD CU ACROSS
S-CNTRL NEB...SOME OF WHICH WILL END UP AS EMBRYOS FOR SHWR
ACTIVITY.

THE 4 KM NAM NESTS ARE HANDLING THE OVERNIGHT SHWR ACTIVITY VERY
WELL VS REALITY AT 3 AM. THEY SUGGEST THAT WHILE AN ISOLATED SHWR
MIGHT DEVELOP BEFORE NOON...THE MAIN INITIATION WILL BE IN THE 2-4
PM TIME FRAME...POSSIBLY IN A BROKEN ARC OF SHWRS THAT TRACKS SE
THRU EARLY EVENING. MORNING POPS MAY BE SCALED BACK OR REMOVED
ALTOGETHER LATER THIS MORNING.

DEWPOINTS REALLY DROPPED YESTERDAY AFTERNOON S OF I-80. SO I USED
A 50-50 BLEND OF THE NAM 2M DWPTS AND MAV MOS /FOR 21Z-03Z/ WHICH
HAVE BEEN VERIFYING THE BEST OVER THE LAST WEEK. 30F SFC DWPT
SPREADS AND CLOUD BASES NEAR 7K FT COULD RESULT IN GUSTY SHWRS.
WOULD NOT BE SURPRISED TO SEE AN ISOLATED GUST OR TWO UP TO 40
MPH.

FCST CONFIDENCE: HIGH

TONIGHT: PARTLY-MOSTLY CLOUDY IN THE EVENING AS SHWRS FADE WITH
LOSS OF HEATING. CANT ENTIRELY RULE OUT AN ISOLATED SHWR SURVIVING
UNTIL MIDNIGHT S AND E OF THE TRI-CITIES. GRADUAL CLEARING FROM
NW-SE AS DIURNAL CLOUDS DISSIPATE AND LEFTOVER CLOUD DEBRIS
DEPARTS TO THE SE.

FCST CONFIDENCE: MEDIUM

USED BIAS CORRECTED CONSENSUS OF MODEL 2M TEMPS FOR BOTH TODAY AND
TONIGHT.

POPS WERE AN EVEN BLEND OF THE 18Z/00Z NAM AND 15Z/21Z SREF...CROSS
CHECKED WITH THE HI-RES NAM NESTS. VERY SHORT-TERM POPS WILL NEED
TO BE INCREASED AS RADAR TRENDS UNFOLD LATER TODAY.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 344 AM CDT THU JUL 31 2014

GUIDANCE SUGGESTS NORTHWESTERLY UPPER TROPOSPHERIC FLOW WILL BE
NOTED OVER THE CENTRAL PLAINS TO START THE LONG TERM FORECAST
PERIOD...AND WILL PERSIST THROUGH SUNDAY OR MONDAY OF NEXT WEEK.
BY EARLY NEXT WEEK...THE WESTERN CONUS UPPER TROPOSPHERIC RIDGE IS
EXPECTED TO BUILD INTO THE CENTRAL CONUS...ALLOWING FOR WEAKENING
UPPER TROPOSPHERIC FLOW...WITH A MORE ZONAL FLOW THEN EXPECTED BY
THE END OF THE LONG TERM FORECAST PERIOD AS AN UPPER TROPOSPHERIC
SHORT WAVE MOVES SOUTH/SOUTHEAST FROM SOUTHERN CANADA.

ALTHOUGH MOST MODEL OUTPUT SUGGEST AN OVERALL LACK IN OMEGA WILL
PRESENT DRY CONDITIONS TO THE AREA UNTIL AT LEAST THE MIDDLE PART
OF NEXT WEEK...THE NAM DOES SUGGEST PRECIPITATION PRODUCTION COULD
BE REALIZED OVER PORTIONS OF THE CWA LATE FRIDAY NIGHT INTO
SATURDAY AS A SUBTLE UPPER TROPOSPHERIC PERTURBATION CLEARS THE
AREA WITHIN THE MEAN NORTHWESTERLY FLOW. SINCE THE NAM IS THE ONLY
MODEL TO SUGGEST PRECIPITATION WILL BE REALIZED OVER OUR
AREA...OPTED TO GO AHEAD WITH A DRY FORECAST FRIDAY THROUGH MONDAY
AND WAIT TO SEE IF OTHER MODELS JOIN THE NAM SOLUTION. HEADING
INTO TUESDAY AND WEDNESDAY...GUIDANCE SUGGESTS OMEGA WILL INCREASE
ACROSS THE REGION AS THE AFOREMENTIONED UPPER TROPOSPHERIC SHORT
WAVE APPROACHES FROM THE NORTH/NORTHWEST. ALLBLEND RESPONDED BY
PROVIDING 20-40% POPS TO MUCH OF THE CWA TUESDAY THROUGH WEDNESDAY
AND THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.

LITTLE IF ANY CHANGE IN THE LOWER TROPOSPHERIC AIR MASS SHOULD
PROMOTE SIMILAR TEMPERATURE READINGS ACROSS THE AREA FROM DAY TO
DAY THROUGH THE LONG TERM FORECAST PERIOD...WITH AFTERNOON HIGHS
IN THE 80S TO NEAR 90 AND OVERNIGHT LOWS IN THE 60S EXPECTED FOR
THE MOST PART.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1220 PM CDT THU JUL 31 2014

PREVAILING VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH
INCREASING MID LEVEL CLOUDS AND A VCSH OR EVEN VCTS POSSIBLE LATER
THIS AFTERNOON THROUGH THE EARLY EVENING HOURS...AS AN AREA OF
SURFACE LOW PRESSURE TRACKS ACROSS CENTRAL NEBRASKA. THEREAFTER...
SKIES ARE EXPECTED TO CLEAR OVERNIGHT AS ANY SHOWER ACTIVITY
SHOULD DISSIPATE AROUND SUNSET...WITH SOUTHERLY WINDS NEAR 10KTS
THIS AFTERNOON EVENTUALLY BECOMING LIGHT AND VARIABLE
OVERNIGHT...BEFORE INCREASING AGAIN OUT OF THE EAST DURING THE
MORNING HOURS FRIDAY.

&&

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

$$

UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...BRYANT
AVIATION...ROSSI