[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 201710
SWODY2
SPC AC 201708

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1208 PM CDT THU MAY 20 2004

VALID 211200Z - 221200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 WSW
HSE 40 NE CLT LEX 35 ESE RFD 20 NW DSM 30 S HSI 15 E AIA 35 S 81V 30
SSE MLS 65 NNE OLF ...CONT... 50 NNW MOT 30 ESE BIS 50 WSW AXN 45
ENE OSC 15 E BUF 45 ENE EKN 40 ESE ORF.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 ESE JAX 40 S GNV
40 SW AGR 55 WNW MIA 20 SSE MIA ...CONT... 30 ESE 7R4 45 SW MLU 15
NW LIT 50 ESE VIH 20 NNE UIN 30 E CNK 30 E P28 45 SW SPS 15 NNW DRT
...CONT... 75 S MRF 35 ENE HOB 60 SSW LBL 45 SW GLD 20 NNW SNY 40
NNE CPR 35 NNW RIW 20 WNW EVW 30 NE ELY 50 N DRA 45 SSW BIH 30 E SCK
10 SW UKI 35 NE ACV 45 N LMT 35 NE RDM 50 SE OLM 15 NNE BLI
...CONT... 40 N ART BOS.

...THERE IS A SLGT RISK OF SVR TSTMS WRN SD/NEB E ACROSS THE MID MS
VLY TO LOWER GREAT LAKES...

...SYNOPSIS...
PERSISTENT UPPER TROUGH OVER THE WRN PARTS OF THE NATION WILL SHOW
SIGNS OF WEAKENING AND EJECTING NEWD BY LATE FRIDAY AS NEXT IMPULSE
DROPS DOWN ERN SIDE OF A RIDGE OVER AK.  DOWNSTREAM RIDGE WILL
BROADEN AND EDGE EWD ACROSS THE SERN PARTS OF THE COUNTRY. 
COMBINATION OF EJECTING WRN CONUS TROUGH AND FLATTENING RIDGE WILL
MAINTAIN MODEST SWLY BELT OF MIDLEVEL FLOW ARCING FROM THE SRN
ROCKIES ACROSS THE PLAINS AND UPPER MS VLY TO NEW ENGLAND.

AT THE SURFACE...WAVY FRONT WILL BE SITUATED FROM NEW ENGLAND ACROSS
THE SRN GREAT LAKES AND INTO THE NRN HIGH PLAINS AT THE START OF THE
PERIOD.  ERN PORTION OF THE FRONT WILL REMAIN NEARLY STATIONARY...
WHILE WRN PORTION MOVES NORTH AS A WARM FRONT ACROSS THE UPPER MS
VLY AHEAD OF EJECTING UPPER TROUGH.  THIS FRONT WILL BE THE FOCUS
FOR TSTM CLUSTERS THAT WILL TRAVERSE FROM THE PLAINS INTO THE MIDDLE
ATLANTIC THROUGH THE NEXT 48 HOURS.

...WRN SD/NEB THROUGH MID MS VLY TO LWR GRT LKS/MID ATL...
TIMING AND LOCATION OF TSTM COMPLEXES WILL CONTINUE TO BE DIFFICULT.
 UNCERTAINTIES WILL ARISE OWING TO THE PRECISE TIMING OF LOW
AMPLITUDE IMPULSES AND INFLUENCES OF THE ELEVATED MIXED LAYER
CAPPING ALONG THE FRONT.  WHILE A SIGNIFICANT SEVERE EVENT MAY BE
POSSIBLE ANYWHERE ALONG THE FRONT...IT IS TOO EARLY/ UNCERTAIN TO
HONE IN ON A SPECIFIC SIGNIFICANT PROBABILITY THREAT.

A FEW MCS/S MAY BE ONGOING TO START THE PERIOD: /1/ MID-UPPER OH
VLY.../2/ UPPER MS VLY AND /3/ ALONG-N OF THE MO RVR IN THE DAKS. 
THE STRONGEST TSTM CLUSTERS WITH HAIL/GUSTY WINDS WILL PROBABLY BE
LOCATED IN THE UPPER MS VLY AND THE NRN PLAINS ALONG THE NOSE OF
50-55 KT LLJ AXES. THESE TSTMS WILL LIKELY BE ELEVATED WITH AMPLE
CLOUD LAYER SHEAR/INSTABILITY TO SUPPORT PERIODIC SEVERE THREATS
CONTINUING FROM LATE IN THE DAY 1 PERIOD.

SURFACE BASED TSTMS WILL LIKELY DEVELOP ALONG FRONT/OUTFLOW
BOUNDARIES ACROSS THE OH VLY/MID-ATLANTIC FRIDAY AFTERNOON. 
STRONGEST DEEP LAYER SHEAR WILL REMAIN NORTH OF THE MASON-DIXON
LINE.  BUT...MIDLEVEL LAPSE RATES SHOULD HAVE RECOVERED TO 6.5-7.0
C/KM SUGGESTING A FEW STORMS MAY POSE A HAIL/DAMAGING WIND THREAT.

MEANWHILE...PORTION OF THE FRONT ACROSS THE UPPER MIDWEST /WRN
OH-SRN LOWER MI-NRN IND/ INTO THE UPPER MS VLY /WI/ COULD BE A FOCUS
FOR SURFACE BASED TSTMS.  CINH WILL BE GREATER ALONG THIS PORTION OF
THE FRONT...BUT IF DEVELOPMENT CAN OCCUR...VERTICAL SHEAR OF 45
KTS...MODEST DIRECTIONAL/SPEED SHEAR IN THE LOWER LEVELS...AND 8
C/KM MIDLEVEL LAPSE RATES WILL BE FAVORABLE FOR LARGE
HAIL...DAMAGING WINDS AND A TORNADO OR TWO.

FARTHER WEST...SURFACE BASED TSTM DEVELOPMENT IS EVEN MORE UNCERTAIN
ACROSS IA/MN/ERN NEB.  H7 TEMPERATURES NEAR 10C AND WEAK CONVERGENCE
ALONG THE FRONT/OUTFLOW SUGGESTS THAT TSTMS MAY HAVE A DIFFICULT
TIME INITIATING.

TSTMS ARE ALSO EXPECTED TO INITIATE ACROSS THE NRN HIGH PLAINS /WRN
SD-WRN NEB/ ALONG A LEE-TROUGH/WARM FRONT.  FORECAST SOUNDINGS
SUGGEST THAT COMBINATION OF STRONG HEATING...MOIST LOW LEVEL UPSLOPE
FLOW AND CONVERGENCE ALONG THE FRONT WILL BE FAVORABLE FOR TSTM
INITIATION BY MID AFTERNOON.  SUPERCELLS ARE LIKELY GIVEN VERTICAL
SHEAR OF 45-50 KTS AND NEARLY DRY-ADIABATIC LAPSE RATES.  DURING THE
EVENING...ACTIVITY SHOULD CONGEAL INTO A MCS AND COULD FORWARD
PROPAGATE RAPIDLY INTO THE MID MO VLY OVERNIGHT WITH DAMAGING
WINDS/HAIL.  IT IS CONCEIVABLE THAT THIS COMPLEX COULD JOIN WITH THE
ACTIVITY THAT DEVELOPS ALONG THE LLJ ACROSS THE UPPER MS VLY BY
EARLY SATURDAY MORNING.

...SRN HIGH PLAINS...
ALL ETAKF MEMBERS OF THE 09Z SREF SUGGEST THAT ISOLD TSTMS COULD
DEVELOP ALONG THE DRYLINE ACROSS SWRN KS/WRN OK AND W TX FRIDAY
AFTERNOON/EVENING. THE RSM/ETA/OPNL ETA DO NOT CONVECT. STRONGEST
CONVERGENCE APPEARS THAT IT WILL BE ACROSS THE KS/OK/NW TX PORTION
OF THE DRYLINE.  GIVEN STRONG HEATING THE CAP COULD BE BREACHED
WHERE CONVERGENCE IS SUFFICIENT.  VERTICAL SHEAR WILL BE ENOUGH FOR
SUPERCELLS AND LARGE HAIL COULD OCCUR WITH THESE STORMS.  WILL
MAINTAIN LOW PROBABILISTIC SEVERE ALL THE WAY TO THE SWRN TX
MOUNTAINS...THOUGH THE HIGHEST THREAT WILL LIKELY REMAIN ALONG NRN
PORTION OF THE DRYLINE.

..RACY.. 05/20/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.