Area Forecast Discussion
Issued by NWS North Platte, NE
Issued by NWS North Platte, NE
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788 FXUS63 KLBF 020929 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 429 AM CDT Thu May 2 2024 .KEY MESSAGES... - A break from the rain today, before precipitation chances return tomorrow, late this weekend, and into early next week. - Very gusty winds this afternoon, especially across the Sandhills, where gusts could exceed 40 miles per hour. Elevated fire weather conditions expected across the western Sandhills and Panhandle this afternoon. - Temperatures remain near seasonal through the weekend into next week. && .SYNOPSIS... Issued at 425 AM CDT Thu May 2 2024 Upper air analysis and satellite imagery show a upper level trough over Wyoming, with another shortwave off the coast of Washington. A line of showers and thunderstorms are observed over eastern Nebraska and eastern Kansas. At the surface, a low pressure system is located over north central Kansas, with a warm front extending along the Kansas-Nebraska state border and a cold front sweeping back across the Oklahoma Panhandle. A second low pressure system is located over western South Dakota, with a cold front extending through the Nebraska Panhandle to near Denver, Colorado. && .SHORT TERM /THROUGH FRIDAY/... Issued at 425 AM CDT Thu May 2 2024 The cold front across the Panhandle will continue to push east this morning and afternoon. The cold front is relatively dry in nature, which will contribute to lowering relative humidity this afternoon as well as clouds clearing out behind the front. Not expecting too much impact to temperatures with this front, as temperatures are generally expected to be in the 60s across the region this afternoon. As the cold front passes through the region, winds will shift from the northeast, and have potential to become quite gusty. In fact, the environment looks very similar to Tuesday this week, where strong gusts were observed across western and north central Nebraska. BUFKIT soundings this morning show a very strong potential for deep mixing this afternoon, with potential for winds around 600 mb to mix down to the surface. This will also help contribute to the dry out behind the front, as much lower humidities in the upper levels are mixed down. Given the very similar set up to Tuesday, went ahead and trended up winds and wind gusts this afternoon. The prime locations for strongest mixing appear to be over the Sandhills and portions of north central Nebraska, where gusts could very well exceed 40 miles per hour this afternoon. Further to the east, roughly along a line from Hayes Center to O`Neill, the forecast soundings still show prolific mixing, but not quite to the extent across the Sandhills. Expect that in these areas, gusts could exceed 30 miles per hour. With the combination of low relative humidities and strong wind gusts this afternoon, elevated fire weather conditions are possible across the Panhandle and western Sandhills this afternoon. Of most concern will be areas that have not received as much rainfall in the past few storms. As the evening sets in, the boundary layer will begin to decouple, allowing surface winds to calm. For Friday, the shortwave currently off the coast of Washington will have trekked eastward over Wyoming, generating another low pressure system and associated cold front. As this system forms, a plume of moisture advection is expected ahead of the system, setting the stage for another round of rain and thunderstorms. Latest CAM guidance is in generally solid agreement for storms to form in the afternoon across the Panhandle and sweep across Nebraska throughout the day. As for the severe weather potential, there is still a bit of uncertainty in the models, particularly in how much CAPE will be available in the environment. For now, the Storm Prediction Center has southwest Nebraska in a Marginal risk for Friday, with wind and hail being the primary concerns at this time. This is likely to be further refined as models come into better consensus on fine details in the environment. Additionally, the Weather Prediction Center has placed a Marginal risk for Excessive Rainfall across southwest Nebraska. Given the decent plume of moisture ahead of the storm system, these storms could be prolific rain producers, so locally heavy rainfall is also expected with these storms Friday afternoon into Saturday morning. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Issued at 425 AM CDT Thu May 2 2024 As the storms move out to the east Saturday morning, a low amplitude ridge is expected to set up over western Nebraska. This will provide another slight break in the rain over the weekend. However, the break is not a long lasting one. A deeper upper level trough begins brings another low pressure system, generating more chances of showers and thunderstorms Sunday afternoon. As the upper level low deepens, the main question will be where the low and upper air dynamics set up on Monday. There is general agreement in the low being over Wyoming/western Nebraska, but some variation remains in the placement of the upper level jet streaks. However, with the upper level support and expected track of the surface system, Monday looks promising for additional rain and thunderstorms. The Storm Prediction Center is already highlighting portions of north central, central, and eastern Nebraska in a 15 percent chance for severe weather on Monday. At this time, there remains some question on the type of severe threat, as a lot depends on how the models begin to resolve some of the finer scale features. Given the potential set up, though, it will be well worth keeping an eye on how this system develops. Beyond Monday, the upper level low is expected to track over the Dakotas, bringing the area under the influence of an upper level trough. Precipitation chances are not looking too robust at this time, generally less than 20 percent on Tuesday. Ensemble guidance does suggest potential for some showers Wednesday into Thursday, around 30 percent, but those numbers drop off to around 10 percent for amounts greater than one tenth of an inch. Temperatures for this period look to remain around seasonal, with highs generally in the 60s and to low 70s. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1240 AM CDT Thu May 2 2024 Poor flight conditions early, then improving to VFR Thursday morning with potential for gusty winds. Low pressure passing by to our southeast will pull the lingering precipitation eastward with it. KVTN is already on the backside of the precipitation and expect KLBF will also be in about another 2 hours. However as the precipitation ends, the boundary layer will stratify and low clouds/fog will develop with IFR/LIFR conditions expected at TAF sites thorugh daybreak, though improvement will be rapid with a return to VFR later Thursday morning. VFR conditions will then persist through the end of the valid period. Winds will generally be light overnight, then become westerly/northwesterly by midmorning with gusty conditions developing. There is a lot of wind at the top of the mixed layer that may reach the surface if mixing is deep enough, so will be watching closely to see how the clearing and heating develop this morning. For now will keep gusts at 30kt for KLBF and 35kt at KVTN this afternoon, but if mixing is robust and allows winds to reach maximum potential, could be looking at gusts 10kt or more above the current TAF values this afternoon especially at KVTN. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Richie SHORT TERM...Richie LONG TERM...Richie AVIATION...MBS