####018003539#### FXUS63 KUNR 032245 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 445 PM MDT Fri May 3 2024 .KEY MESSAGES... -Rain shifting east out of the forecast area this evening. -Warmer and breezy this weekend. -Strong storm system early next week with the potential for several hazards: locally heavy rain Monday/Tuesday (northeastern Wyoming/northwestern South Dakota), high winds Tuesday/Wednesday, some snow for the Black Hills Tuesday/Wednesday. && .DISCUSSION...(This Evening Through Friday) Issued at 144 PM MDT Fri May 3 2024 Cold upper low across southern Canada continues to lift out of the region this afternoon. Southern periphery impulse along the stalled baroclinic zone has supported rain/snow across the southeast half today and will continue to shift ESE with the associated FGEN area. Expect rain to develop and shift SE across scentral SD this afternoon and taper off by evening. Skies will clear out across most places tonight with dry air spreading into the region. This will allow for a cool night with lows in the 20s/30s and some teens in the Black Hills. Warmer and dry Sat with highs generally in the 60s. Strong western CONUS upper trough will then shift east into the Rockies and support pressure falls over the region Sun. This will force increasing SE winds, becoming quite breezy by afternoon across the NW SD plains where adv winds are likely. Pos theta-e adv with a weakening cap may allow for a thunderstorm or two over NE WY in the afternoon. However, better chances for more widespread rains will arrive Sunday night with the main moisture surge and WAA. Strong storm system will then move onto the plains Monday, with the sfc trough/dryline shifting east across southwest through scentral SD. Current progs suggest that the severe threat will remain south and east of the FA, but if things slow down some, there may be a small window for severe weather across far scentral SD. Further west, deformation rains will spread into the region along with gusty NW winds. Adv to low end warning winds will be possible Monday across much of western SD, with the bulk of wind in NW SD. However, rains may limit mixing and gust potentials. As the upper low stalls and then slowly migrates east, winds, rain, and cool weather will persist through Wed night. Rain will change to snow in the higher elevations of the Black Hills Monday night with some light accums possible. However, the better chance for snow accums looks to be Tue night into Wed when colder air advects into the region. Things will begin to slowly warm up and dry out toward next weekend as the upper low finally exits the region. && .AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening) Issued At 439 PM MDT Fri May 3 2024 Showers are slowly moving out of southwestern and south central SD and will continue to exit the forecast area from west to east through 06z. Locally MVFR/IFR conditions associated with this precip can be expected in southwestern and south central SD, especially near the stronger showers. VFR conditions expected elsewhere in the forecast area. Gradual improvement to VFR area wide will occur overnight and persist through the TAF period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...JC AVIATION...Wong ####018004873#### FXUS61 KBGM 032248 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 648 PM EDT Fri May 3 2024 .SYNOPSIS... High pressure will give way to a slow moving frontal boundary that will push through the area Sunday. High pressure looks to be short lived early next week before another frontal boundary and areas of low pressure move through most of next week. && .NEAR TERM /THROUGH SATURDAY NIGHT/... 645 PM Update... There was not much to change with this update. Sky cover was lowered some, at least until the showers from the west move in. The slow moving showers are expected to move in later this evening, so PoPs were left untouched for now. Temperatures and dew points were touched up based on the latest conditions. Most locations are still in the 70s. Otherwise, conditions remain quiet for now as we monitor the showers in western NY and PA. Previous Discussion... High pressure in place across our region will attempt to slow down a cold front approaching from the Great Lakes. This should keep most of the showers with the front west and south of the region through most of Saturday. Though a few of the models have a glancing blow from some light showers in NE PA and west of the Finger Lakes in NY. Coverage of showers should ramp up Saturday night given increasing moisture and lift ahead of the frontal boundary. QPF through Saturday night looks to be a half inch or less, so no concern for flooding issues. Instability also looks to be very little if any does happen to develop. Temperatures tonight look to be a few degrees warmer due to clouds only falling to around 50 then struggle to rise into the low 60's on Saturday. Lows look to end up a few degrees cooler Saturday night. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... 120 PM Update... Zonal flow pattern aloft keeps conditions relatively active during this period. Rain showers are expected to continue on Sunday as an occluded front slowly moves eastwards. Meanwhile a low pressure system over the Great Lakes drags a cold front into our region by Sunday evening. This will bring more showers with a few thunderstorms possible in the evening hours. Rainfall amounts are up to a quarter inch but any evening thunderstorms that develop could drop an inch of rain. Instability parameters are weak on model guidance, therefore not expecting much concern with these storms. Temperatures cool on Sunday with highs ranging in the low 50s to low 60s. Overnight temperatures are not expected to deviate far off of daytime highs. Lows will range in the upper 40s to mid 50s. A secondary cold front could bring some scattered rain showers Monday through Monday night. Not expecting a lot of rain with this system as the levels remain relatively dry. Precip chances are more favorable to the south of our region. Otherwise once this weak system moves thorough conditions remain dry overnight with brief high pressure building in over the Great Lakes. Temperatures on Monday will climb into the upper 60s to mid 70s in the afternoon and fall into the upper 40s to low 50s overnight. && .LONG TERM /TUESDAY THROUGH FRIDAY/... 120 PM Update... A warm front draped over the midwest approaches the region on Tuesday. Model guidance shows some timing differences in the arrival of this system. Regardless showers are expected to move in at least by the evening time frame and last overnight. This should leave most of Tuesday precipitation free. As of now Tuesday appears to be the driest day during this period. Warm front passes sometime Wednesday through Thursday bringing in more rain showers with afternoon thunderstorms. Similar pattern continues into Friday as well with yet another disturbance moving into the region. Otherwise temperatures during this period will remain mild with highs in the upper 60 to upper 70s and lows in the upper 40s to mid 50s. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... VFR throughout the TAF period with southerly winds 10 knots or less. Some lowering of ceilings late in the TAF period. Outlook... Saturday afternoon through Sunday night...A couple passing frontal boundaries will result in scattered showers and restrictions, especially Saturday night onward. Isolated thunderstorms will also be possible. Monday... Mainly VFR. Monday Night through Wednesday...VFR then increasing chance of rain and restrictions Tuesday afternoon through night. Embedded thunder also possible late Tuesday. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MWG NEAR TERM...BTL/MWG SHORT TERM...ES LONG TERM...ES AVIATION...MPK