MESOSCALE DISCUSSION 2049
NWS STORM PREDICTION CENTER NORMAN OK
0346 PM CDT THU AUG 19 2004
AREAS AFFECTED...PORTIONS ERN ORE...EXTREME SERN WA...SWRN ID...NERN
NV...EXTREME NWRN UT
CONCERNING...SEVERE THUNDERSTORM POTENTIAL
VALID 192046Z - 192315Z
WIDELY SCATTERED TSTMS WILL CONTINUE TO DEVELOP -- PRIMARILY OVER
HIGHER TERRAIN -- AND MOVE GENERALLY SEWD WITH POTENTIAL FOR
OCCASIONAL STRONG-SEVERE GUSTS AND HAIL. WW NOT ANTICIPATED ATTM
BECAUSE OF MARGINAL AND LOOSELY ORGANIZED CHARACTER OF SEVERE
THREAT.
MOISTURE CHANNEL IMAGERY INDICATES SHORTWAVE TROUGH WITH TWO
MID/UPPER LEVEL VORTICITY MAXIMA -- ONE OVER NWRN ORE AND THE OTHER
OVER NWRN MT. THESE FEATURES WILL MOVE SEWD ACROSS NRN PART OF
DISCUSSION AREA THROUGH REMAINDER AFTERNOON AND...IN COMBINATION
WITH INSOLATION...CONTRIBUTE TO FAVORABLE DESTABILIZATION. MODIFIED
12Z RAOBS AND RUC SOUNDINGS INDICATE STEEP LOW-MIDLEVEL LAPSE RATES
8-9 DEG C/KM ABOVE WELL-MIXED...INVERTED-V THERMODYNAMIC PROFILE IN
BOUNDARY LAYER. MAX INSTABILITY SHOULD REMAIN WITHIN ABOUT 50-60 NM
EITHER SIDE OF LINE FROM ALW...BKE...50 SW BOI...ENV. SFC DEW
POINTS COMMONLY RANGE FROM MID 40S TO UPPER 50S F...WITH MLCAPE
REACHING 1000-1500 J/KG NEAR INSTABILITY AXIS. VERTICAL WIND SHEAR
WILL REMAIN LIMITED GIVEN RELATIVELY WEAK LOW-MIDLEVEL WIND FIELDS
OF BELOW 20 KT...HOWEVER BOUNDARY/OROGRAPHIC ENHANCEMENTS TO
NEAR-SFC KINEMATIC FIELDS MAY AUGMENT BOUNDARY LAYER SHEAR PROFILES
AND CONTRIBUTE TO CONVECTIVE INTENSITY LOCALLY.
..EDWARDS.. 08/19/2004
ATTN...WFO...SLC...PIH...MSO...BOI...LKN...OTX...PDT...MFR...
40681463 41181607 41921753 42271963 43431841 44512039
45411858 45591820 45891792 46291756 46351714 46141663
45541633 45091626 44201667 43361687 42751593 42161440
41951354 41661338 41261343 40911380 40701429
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