- -URGENT - IMMEDIATE BROADCAST REQUESTED -Tornado Watch Number 163 -NWS Storm Prediction Center Norman OK -135 PM CDT Tue Apr 30 2024 - -The NWS Storm Prediction Center has issued a - -* Tornado Watch for portions of - Southern and Western Iowa - Eastern Nebraska - -* Effective this Tuesday afternoon and evening from 135 PM until - 1000 PM CDT. - -* Primary threats include... - A few tornadoes possible - Scattered damaging winds and isolated significant gusts to 80 - mph likely - Scattered large hail and isolated very large hail events to 2.5 - inches in diameter likely - -SUMMARY...Severe thunderstorms will develop this afternoon over -eastern Nebraska and track eastward across the watch area through -the evening. - -The tornado watch area is approximately along and 60 statute miles -north and south of a line from 50 miles north northwest of Lincoln -NE to 35 miles east of Knoxville IA. For a complete depiction of the -watch see the associated watch outline update (WOUS64 KWNS WOU3). - -PRECAUTIONARY/PREPAREDNESS ACTIONS... - -REMEMBER...A Tornado Watch means conditions are favorable for -tornadoes and severe thunderstorms in and close to the watch -area. Persons in these areas should be on the lookout for -threatening weather conditions and listen for later statements -and possible warnings. - -&& - -AVIATION...Tornadoes and a few severe thunderstorms with hail -surface and aloft to 2.5 inches. Extreme turbulence and surface wind -gusts to 70 knots. A few cumulonimbi with maximum tops to 500. Mean -storm motion vector 27035. - -...Hart - --Read more -]]> -
- -STATUS REPORT ON WW 163 - -THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. - -..LYONS..04/30/24 - -ATTN...WFO...DMX...OAX...FSD... - - -STATUS REPORT FOR WT 163 - -SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS - -IAC001-003-007-009-015-025-027-029-039-047-049-051-053-071-073- -077-085-093-099-117-121-123-125-129-133-135-137-145-153-155-157- -159-161-165-169-173-175-179-181-185-193-302040- - -IA -. IOWA COUNTIES INCLUDED ARE - -ADAIR ADAMS APPANOOSE -AUDUBON BOONE CALHOUN -CARROLL CASS CLARKE -CRAWFORD DALLAS DAVIS -DECATUR FREMONT GREENE -GUTHRIE HARRISON IDA -JASPER LUCAS MADISON -MAHASKA MARION MILLS -MONONA MONROE MONTGOMERY -PAGE POLK POTTAWATTAMIE -POWESHIEK RINGGOLD SAC -SHELBY STORY TAYLOR -UNION WAPELLO WARREN -WAYNE WOODBURY - - -NEC021-023-025-037-039-043-053-055-109-119-131-141-151-153-155- -159-167-173-177-302040- - --Read more -]]> -
- -Mesoscale Discussion 0576 -NWS Storm Prediction Center Norman OK -0235 PM CDT Tue Apr 30 2024 - -Areas affected...parts of eastern Kansas - -Concerning...Severe potential...Watch possible - -Valid 301935Z - 302130Z - -Probability of Watch Issuance...60 percent - -SUMMARY...Intensifying thunderstorm development is probable through -4-7 PM CDT, including a few supercells with potential to produce -large hail, locally damaging wind gusts and a risk for tornadoes. - -DISCUSSION...To the south of a strong, broadly cyclonic mid/upper -jet nosing east of the Front Range, toward the the middle Missouri -Valley, warm elevated mixed-layer air remains inhibitive to -convective development in the presence of weak to negligible -mid/upper forcing for ascent. However, where the cold front is -overtaking a sharpening dryline across the Salina vicinity of north -central Kansas, more notable deepening of convective development is -ongoing. - -Aided by a corridor of stronger pre-frontal boundary-layer heating, -including surface temperatures exceeding 90F along an axis across -northwestern Oklahoma into the Salina vicinity, mixed-layer CAPE now -appears in excess of 2000 J/kg along the sharpening dryline. With -additional insolation, it appears that low-level forcing near the -cold front/dryline intersection may become sufficient to support -sustained thunderstorm development as early as 21-22Z. In the -presence of moderate but veering flow with height in the 850-500 mb -layer, vertical shear will be conducive to supercell development, at - least initially, and perhaps an upscale growing line with -persistent supercell development along its southern flank, gradually -approaching the Wichita area through early evening. - -..Kerr/Hart.. 04/30/2024 - -...Please see www.spc.noaa.gov for graphic product... - -ATTN...WFO...EAX...TOP...ICT...OUN...DDC... - -LAT...LON 38499761 39979640 39699511 37819607 36929748 37309836 - 38499761 - --Read more -]]> -
- -Mesoscale Discussion 0575 -NWS Storm Prediction Center Norman OK -0229 PM CDT Tue Apr 30 2024 - -Areas affected...parts of eastern South Dakota...Northern Iowa and -southern Minnesota - -Concerning...Severe potential...Watch possible - -Valid 301929Z - 302130Z - -Probability of Watch Issuance...40 percent - -SUMMARY...Scattered thunderstorms over eastern SD may grow upscale -into a more organized line/cluster with time. Damaging winds and -hail are possible, but the coverage and severity are uncertain. A -Severe Thunderstorm Watch is possible. - -DISCUSSION...Ahead of the advancing shortwave trough, thunderstorms -have initiated along a pre-frontal trough/convergence zone across -parts of eastern SD and northeastern NE. North of a modifying -outflow boundary/effective warm front, the air mass has slowly -moistened and warmed into the low 60s F. While not overly unstable, -heating through scattered cloud breaks and further moistening will -continue to allow for destabilization with SPC mesoanalysis showing -~500-1000 J/kg of MUCAPE. Effective straight-line hodographs will -favor a linear/cluster mode with further upscale growth from storm -interactions likely. Given the storm mode and modest buoyancy, -damaging winds appear to be the most likely threat. However, -occasional hail and a brief tornado will also be possible with any -embedded supercell/bowing structures able to develop. Buoyancy -decreases farther east indicating some uncertainty on the coverage -and timing of the severe risk. Still, mesoscale trends suggest -further destabilization is likely and a downstream severe risk may -develop. With this in mind, a Severe Thunderstorm Watch is possible. - -..Lyons/Hart.. 04/30/2024 - -...Please see www.spc.noaa.gov for graphic product... - -ATTN...WFO...ARX...MPX...DMX...FSD...OAX... - -LAT...LON 42249290 42419701 42539722 43629719 44289665 44089414 - 43779337 43299248 43179231 42969236 42399253 42309263 - 42249290 - --Read more -]]> -
-Day 1 Convective Outlook -NWS Storm Prediction Center Norman OK -1129 AM CDT Tue Apr 30 2024 - -Valid 301630Z - 011200Z - -...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON -AND EVENING ACROSS PARTS OF WESTERN IOWA...SOUTHEAST -NEBRASKA...NORTHEAST KANSAS...AND NORTHWEST MISSOURI... - -...SUMMARY... -The greatest threat for severe weather (large hail, severe gusts, -and a few tornadoes) is from western and central Iowa to -northeastern Kansas. - -...Eastern NE/Western IA/Northwest MO/Northeast KS... -Water vapor loops show a fast-moving shortwave trough and associated -mid/upper level speed max moving across the central Rockies into the -Plains. Ahead of this trough, southerly low-level winds are -transporting moisture northward with dewpoints in the 60s now as far -north as southeast NE. Continued daytime heating and moisture -advection will lead to a narrow corridor of moderate CAPE over -eastern NE by mid-afternoon. A consensus of morning model guidance -indicated that thunderstorms will form in this regime, with other -intense storms developing southward along the surface cold front -into northeast KS by late afternoon. Forecast soundings show shear -profiles favorable for supercell structures capable of very large -hail and a few tornadoes. After dark, these storms are expected to -congeal into one or more bowing structures that will track eastward -into central IA/northern MO with a greater risk of damaging wind -gusts along with hail and perhaps tornadoes. - -...Eastern KS/Western OK/Northwest TX... -The surface dryline will extend southward from northeast KS into -northwest OK and northwest TX. Isolated intense storms are expected -from roughly Wichita northward, with decreasing confidence from -there southward. Weak large scale forcing, rising mid level -heights, and generally warming temperatures at 700mb suggest any -storms that form along the dryline will be widely scattered. -However, large CAPE values, steep mid level lapse rates, and -sufficient vertical shear will support supercell structures capable -of all severe hazards in any storm that can form/sustain. Will -maintain the ongoing SLGT/MRGL areas at this time, but will -reevaluate at 20z. - -...NY/PA... -Strong daytime heating is occurring over areas from central NY into -central PA, where dewpoints are in the upper 50s. Forecast -soundings suggest afternoon MLCAPE values of 500-1000 J/kg, leading -to scattered afternoon thunderstorms. Low-level winds are -relatively weak/veered, but sufficient winds aloft and steep -low-level lapse rates could contribute to a risk of gusty/damaging -wind gusts and hail in the strongest cells this afternoon. - -..Hart/Lyons.. 04/30/2024 - --Read more -]]> -
-Day 2 Convective Outlook -NWS Storm Prediction Center Norman OK -1234 PM CDT Tue Apr 30 2024 - -Valid 011200Z - 021200Z - -...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN A PART OF -SOUTHWEST KS TO NORTHWEST OK... - -...SUMMARY... -Scattered severe thunderstorms are possible across parts of the -central and southern Great Plains from Wednesday afternoon into -Wednesday night. A few tornadoes, very large hail, and damaging -winds are anticipated. - -...Synopsis... -In the wake of a vigorous shortwave trough moving across the Upper -Great Lakes to the Saint Lawrence Valley, an upstream shortwave -impulse will gradually shift east from the northern Rockies to the -northern High Plains. The initial cold front on D1 over the central -Great Plains will stall and advance north as a warm front Wednesday -night. Convective outflows from residual D1/early D2 convection -should exist south of this boundary in parts of OK. - -...Central Great Plains... -Consensus of guidance continues to trend south with the placement of -the quasi-stationary front expected to be lying across southern KS -at 12Z Wednesday. A pronounced low-level jet should restrengthen -during the day, which will probably yield a swath of elevated -convection spreading northeast across the Mid-MO Valley with perhaps -a marginal severe hail threat. How far north the front will advance -during the day is uncertain with above-average spread across -guidance, but near its intersection with the surface dryline in the -southwest to west-central KS vicinity should be the most favorable -combination of the thermodynamic/kinematic environment. With -near-neutral mid-level height change through early evening, -convergence along the dryline will be necessary for late afternoon -thunderstorm development. Guidance largely suggests convective -coverage will remain isolated at most. But within a highly favorable -environment for supercells, tornadoes and very large hail will be -possible. - -On Wednesday evening into the night, the plume of returning -low-level moisture coupled with increasing large-scale ascent -downstream of the northern Rockies to High Plains should lead to -largely elevated storms developing in the CO/NE/KS border vicinity. -Much of this convection should remain north-northwest of the surface -warm front and likely remain elevated until very late in the period. -But with very steep lapse rates aloft, a strong low-level jet and -strong forcing for ascent, an elevated MCS capable of producing both -large hail and severe surface wind gusts remains possible. - -...Southern Great Plains... -Strong heating will occur near the dryline, where an uncapped and -very unstable air mass will develop with MLCAPE of 3000-3500 J/kg. -Bulk of guidance suggests appreciable convective development will -occur in west TX, where a minor mid-level impulse may emerge within -the modest southern-stream flow regime. More isolated dryline storms -should form farther north, perhaps intersecting with residual -outflows from remnant convection in OK on Wednesday morning. - -Deep-layer shear compared to early May climo will be relatively -modest, but the ample buoyancy coupled with numerous storms should -yield a mixed cluster and transient/slow-moving supercell mode. -Large to significant severe hail and sporadic severe wind gusts will -be possible. Potential will exist for upscale growth into -slow-moving clusters that move east into central parts of TX during -the evening and likely linger overnight, with a gradually subsiding -severe threat during these time frames. - -..Grams.. 04/30/2024 - --Read more -]]> -
-Day 1 Fire Weather Outlook -NWS Storm Prediction Center Norman OK -1123 AM CDT Tue Apr 30 2024 - -Valid 301700Z - 011200Z - -Trimmed the northeast portion of the Elevated area based on forecast -frontal position today. Otherwise, the forecast remains on track. -See previous discussion below. - -..Bentley.. 04/30/2024 - -.PREV DISCUSSION... /ISSUED 0110 AM CDT Tue Apr 30 2024/ - -...Synopsis... -A belt of enhanced mid-level flow will spread across the Northern -Rockies from an upper low across the northwestern US today. A -cold frontal passage will bring rainfall across much of eastern -Montana and Wyoming this morning. Behind the cold front, a dry -continental air mass will overspread this region into the western -Dakotas, with relative humidity dropping as low as 15 percent amid -sustained winds 20-25 mph. Fuels within southern Montana into the -western Dakotas, where less rainfall is forecast, are sufficiently -dry to carry risk of Elevated fire weather concerns. - -...Please see www.spc.noaa.gov/fire for graphic product... - --Read more -]]> -
-Day 2 Fire Weather Outlook -NWS Storm Prediction Center Norman OK -0202 PM CDT Tue Apr 30 2024 - -Valid 011200Z - 021200Z - -...CRITICAL FIRE WEATHER AREA FOR EASTERN NEW MEXICO INTO THE FAR -WESTERN OK/TX PANHANDLES... - -No changes. See previous discussion below. - -..Bentley.. 04/30/2024 - -.PREV DISCUSSION... /ISSUED 0151 AM CDT Tue Apr 30 2024/ - -...Synopsis... -Dry and breezy conditions are expected across the southern High -Plains on Wednesday in response to a development of a lee cyclone, -as increasing mid-level flow overspreads the Rockies. Deeply mixed -profiles by the afternoon will yield single-digit relative humidity -amid sustained winds 20 to 25 mph across portions of eastern New -Mexico into the northern Texas Panhandle. Little recent rainfall -across this area has sufficiently dried fuels, with ERCs forecast to -be in the 75th percentile. This will support Critical fire weather -concerns, with broader Elevated fire weather concerns extending into -southeastern Colorado and the western Oklahoma Panhandle. - -...Please see www.spc.noaa.gov/fire for graphic product... - --Read more -]]> -