Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 AM CDT Sun Apr 02 2017 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF THE SOUTH CENTRAL PLAINS INTO THE OZARKS... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE TUESDAY NIGHT ACROSS PARTS OF THE CENTRAL GULF COAST STATES... ...SUMMARY... Strong thunderstorm activity is possible across parts of the south central Plains into the Ozarks late Tuesday afternoon into Tuesday night, and across parts of the central Gulf Coast states late Tuesday night, accompanied by some risk for severe weather. ...Synopsis... Mid/upper flow across the U.S. appears likely to remain progressive through this forecast period, but models suggest that the pattern may undergo increasing amplification across the Pacific Coast into the Plains by 12Z Wednesday. This is expected to occur as a large upper trough develops near the leading edge of a strong mid-latitude Pacific jet, and approaches the Canadian/U.S. Pacific coast. Within split downstream westerlies, a vigorous southern branch impulse is forecast to turn east of the southern Rockies, with significant surface cyclogenesis continuing northeast of the Texas Panhandle region through the south central Plains. At the same time, northern stream troughing may dig east of the Canadian Rockies through the Canadian Prairies and adjacent international border area, but the two streams are expected to remain out of phase through this period. Farther downstream, a deamplifying short wave impulse appears likely to accelerate east of the upper Ohio Valley, and off the north Atlantic coast. Renewed surface cyclogenesis is possible commencing early in the period near northern Mid Atlantic and southern New England coastal areas, with considerable low-level drying in its wake, across the mid/southern Atlantic Seaboard. Guidance does appear increasingly suggestive that substantive boundary layer moisture return to Gulf coastal areas is possible by late Tuesday night, but moistening within the warm sector of the Plains cyclone is expected to remain much more modest through at least this forecast period. ...South central Plains into the Ozarks... Despite limited moisture return, steepening lapse rates associated with strong mid/upper forcing for ascent and differential thermal advection is expected to contribute to at least weak CAPE near the slowly deepening surface cyclone center by late Tuesday afternoon. In the presence of strong shear, vigorous convection accompanied by a risk for severe weather appears possible, perhaps including a couple of supercells, and could spread into the Ozarks Tuesday night. ...Central Gulf States... Deterministic guidance appears more bullish than the ensemble output (particularly the NCEP SREF) suggests concerning low-level moisture return and potential for vigorous thunderstorm development prior to 12Z Wednesday. If this occurs, it will probably do so in the presence of strengthening shear supportive of some severe weather potential, including a risk for supercell development. ..Kerr.. 04/02/2017Read more
from SPC Forecast Products http://ift.tt/GAMjPN
No comments:
Post a Comment