Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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355 FXUS61 KPBZ 221055 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 655 AM EDT Sat Jun 22 2024 .SYNOPSIS... Dangerous heat will continue today. Showers and thunderstorms return Sunday with a crossing cold front. A few of these storms could be severe. Temperatures closer to seasonable levels are expected behind the front on Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... KEY MESSAGES: - Dangerous heat continues today - Excessive Heat Warning and Heat Advisory remain in effect ------------------------------------------------------------------- Update... Reduced the coverage of the patchy fog this morning, based on recent satellite and surface observations. Previous discussion... The upper high remains across much of the South Central and Southeast CONUS, with the Upper Ohio Valley region on the northern periphery of the high. The high, along with low and mid level ridging, will keep most of the area dry today. There could be isolated afternoon showers and thunderstorms that develop north of I 70 as convective temperatures are reached, though the more likely scenario will be cumulus cloud formation. Dry air aloft should make it difficult for shower/thunderstorm development to occur, though areas closer to I 80 could see a slightly higher potential as the lake breeze moves south. The main story today will be the heat. 500mb heights will be similar to Friday, before beginning to fall slightly later in the day. 850 mb temperatures are progged to be near, or slightly higher than Friday, peaking near 20 deg C. Overall, with the mostly sunny skies and very little if any convection, high temperatures should be similar to Friday`s readings. Heat indices are expected to range from 95 to 100, outside of the higher terrain of WV. Will maintain the current heat headlines through 8 PM. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... KEY MESSAGES: - Crossing cold front brings showers and thunderstorms Sunday - Severe storms possible Sunday - Return to seasonable temperatures on Monday ------------------------------------------------------------------- Very warm temperatures will continue tonight as cloud cover and southwest wind increase tonight ahead of an approaching cold front. A shortwave trough, and the associated cold front, is expected to approach the region Sunday. Most available model output indicates a prefrontal trough will cross the region from mid morning through early afternoon, with the cold front crossing through the late afternoon/evening. Increasing instability and shear is progged through the day, with ensemble based mean MU CAPE 1500-2000 j/kg by Sunday afternoon/evening, with the max surface based CAPE 2000-3000 j/kg. 0-6km bulk shear values also increase to 35-40kt, with dry mid level air enhancing downdraft CAPE. A low level jet from 35-40kt at 850mb will also enhance the damaging wind potential. Curved hodographs in the lower levels also indicate some rotation/isolated tornado potential. The Storm Prediction Center has placed much of western PA in a Slight Risk for severe storms. The main hazard is expected to be damaging wind, though with the curved hodographs and shear isolated tornadoes are also possible. The Slight Risk area is surrounded by a Marginal Risk, where FROPA timing and shear profiles are slightly less favorable for severe storms. The cold front will complete its passage Sunday evening, with showers and thunderstorms ending from W-E. Surface high pressure is expected to build under a crossing upper trough on Monday. This should return mainly dry, and more seasonable weather to the region. && .LONG TERM /TUESDAY THROUGH FRIDAY/... KEY MESSAGES: -Above average temperatures return -Mainly dry to start and end the work week, with shower and thunderstorms for mid week ------------------------------------------------------------------- An upper ridge, ahead of an approaching Midwest trough, will maintain dry weather on Tuesday. Rising 1000-500mb heights and warm advection will drive temperatures from 5 to 10 degrees above average. The trough, and its associated surface cold front, will approach and cross the region late Tuesday night through Wednesday evening, with shower and thunderstorm chances returning. Building high pressure will return dry weather for Friday, with temperatures closer to average. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... High probability for VFR to persist through the TAF period under the influence of high pressure. Warm, dry air aloft should limit convective initiation and keep probabilities very low of terminal impact with an afternoon thunderstorm. Approach of an upper level shortwave and associated cold front will increase thunderstorm chances at the end to after the TAF period. .Outlook... Showers and thunderstorms are likely, with associated restrictions, along and ahead of an advancing cold front Sunday. Timing favors near to after 18z Sunday (2pm EDT) through 06z Monday (2am EDT). High pressure and northerly flow aloft will establish dry and more seasonable conditions for the start of the next work week. && .CLIMATE... The area has the potential to break various heat-related records. There is low probability that climate sites approach the highest temperatures recorded in the 21st century: Pittsburgh, PA: 98F (7/7/2012) Wheeling, WV: 98F (7/7/2012) Morgantown, WV: 101F (7/7/2012) New Philadelphia, OH: 101F (7/7/2012) Zanesville, OH: 101F (7/7/2012) DuBois, PA: 101F (7/22/2011) There is a low probability many June all-time temperature records may be at stake: PIT: 98F (1988) HLG: 100F (1933) MGW: 99F (1893) PHD: 99F (1988) ZZV: 101F (1988,1934) DUJ: 92F (1969) *RECORD TIED ON 6/18/24* Daily high maximum (left) and high minimum (right) temperature records are at stake for: Saturday, June 22nd Pittsburgh, PA: 98F (1988) 75F (1988) Wheeling, WV: 95F (1923) 72F (2011) Morgantown, WV: 96F (1923,1988)73F (1988) New Philadelphia, OH: 97F (1988) 71F (1997) Zanesville, OH: 99F (1988) 71F (1997) DuBois, PA: 91F (2022) 68F (2022) && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...Heat Advisory until 8 PM EDT this evening for PAZ007>009-013- 015-016-022-031-074-076>078. Excessive Heat Warning until 8 PM EDT this evening for PAZ014- 020-021-029-073-075. OH...Heat Advisory until 8 PM EDT this evening for OHZ039>041- 048>050-057>059-068-069. WV...Heat Advisory until 8 PM EDT this evening for WVZ001>004-012- 021-509>511. && $$ SYNOPSIS...WM NEAR TERM...WM SHORT TERM...WM LONG TERM...WM AVIATION...Frazier CLIMATE...