![]() An expansive cold front will extend southwestward from this low, stretching through the Upper OH Valley through the Mid-South and into South TX early Saturday morning. Secondary shortwave will likely progress eastward/southeastward across central/southern MO and into TN Valley.Īt the surface, an occluded low associated with the primary shortwave will likely begin the period over southwestern Ontario before then moving northeastward through eastern Ontario and southern Quebec. The primary shortwave is forecast eastward through southwestern Ontario before turning more northeastward as it moves over the Lower Great Lakes and St. Primary shortwave trough is expected to be over Lower MI early Saturday morning, with another weaker shortwave farther west over the Lower MO Valley. Isolated severe thunderstorms are possible Saturday across much of the Southeast, and from the Edwards Plateau into the Rio Grande Valley in Texas. Valid 201200Z - 211200Z THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE SOUTHEAST…AND FROM THE EDWARDS PLATEAU INTO THE RIO GRANDE VALLEY IN TEXAS. Outlook Imagesĭay 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Fri May 19 2023 Outlook for Saturday, May 20 Outlook Summary NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z ← back to overview The severe threat is on the lower margins for any probabilities, and this area will continue to be re-evaluated today. Inverted-V profiles, DCAPE of 750-1000 J/kg, and MLCAPE of 500-1000 J/kg will support some potential for strong outflow gusts with a cluster of storms this evening. Lingering low-level moisture, surface heating in cloud breaks, and midlevel flow from the northeast at 15-20 kt will allow convection over the Mogollon Rim to spread southwestward into the lower deserts over west central AZ. The severe threat is low with these storms, but there is still some potential for a Marginal risk area in later updates. Vertical shear will be rather weak, but multicell clusters could produce isolated strong outflow gusts and small hail later this afternoon from crest of the Cascades into north central OR. Forcing for ascent appears to be nebulous, so terrain circulations will be the primary driver of thunderstorm development this afternoon near the crest of the Cascades. Modest low-midlevel moisture will persist in a south-southwesterly flow regime again today across OR/WA. The hail/wind threat will slowly diminish by 03-06z as the low levels stabilize and convective inhibition increases. ![]() Storms will persist into this evening and at least early tonight, developing southward toward the Hill Country in TX, and east-southeastward into western AR. Thus, there will be some potential for a supercell or two across east central OK this afternoon, given sufficient surface heating in cloud breaks. Lapse rates and surface heating will be weaker into eastern OK, but vertical shear will be a little stronger along the south flank of the primary MCV. Vertical shear across TX will be in the range supporting multicell clusters and some transient supercells, capable of producing large hail and occasional damaging outflow gusts. As a result, the steeper low-midlevel lapse rates are expected across TX, where afternoon temperatures near 90 F and boundary-layer dewpoints at least in the mid 60s will contribute to MLCAPE in excess of 3000 J/kg. Lingering clouds add some uncertainty to the degree of surface heating today in OK, with stronger surface heating and more cloud breaks likely with southward extent into TX. Weakening outflow could persist through the day across OK into central TX, with storm development possible along the lingering outflow as well as the cold front. The primary MCV will likely persist through the day across north central/northeast OK, while a surface cold front (in the wake of the MN shortwave trough) will move southeastward into the I-44 corridor across OK and northwest TX by late afternoon. Within a generally weak flow regime between a northern stream shortwave trough over MN and subtropical ridging over northern Mexico, a couple of MCVs are moving eastward over OK/southern KS this morning. Eastern OK/western AR into central TX this afternoon/evening Strong/locally severe storms are expected this afternoon and evening from parts of the southern Plains eastward into parts of Arkansas. Valid 191300Z - 201200Z THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR CENTRAL TX INTO EASTERN OK/WESTERN AR Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0753 AM CDT Fri May 19 2023
0 Comments
Leave a Reply. |