####018006262#### FXUS65 KPIH 280931 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 331 AM MDT Thu Mar 28 2024 .SHORT TERM...Today through Friday Night. Plenty of moisture is already moving through eastern Idaho this morning as evidenced by both satellite and radar returns. At this point, we are seeing snow up in the mountains and rain at the lower elevations as expected. More precipitation will spread eastward through the morning as this first wave of energy and associated cold front are ejected from the low sitting off the coast of the PNW. This is a fairly quick moving system as the Central Mountains will be drying out already by the late afternoon/early evening period and the Eastern Highlands will mostly be done with snow by 9 PM. Some minor increases in snow totals tipped the scales in favor of Winter Weather Advisories for the Island Park/Centennial Mountains and Bear River Range areas until 9 PM this evening. Snow totals will be around 4 to 8 inches around the Island Park areas with totals closer to the 6 to 8 inch range at Raynolds and Targhee Passes. Down south, snow totals near Emigration Summit will also be in the 4 to 8 inch range, though there is about a 30 to 40 percent chance totals will be closer to 10 inches at the top of the summit there. In the Magic Valley and Snake Plain, precipitation will generally remain all rain (up to about three tenths of an inch), but some snow could mix in at times. If temperatures cool a few degrees more, snow totals could push towards an inch. There is about a 30 percent chance of at least an inch in Pocatello and Idaho Falls by Friday morning. The valley towns in the Southeastern Highlands will be an area to watch today with the potential to over-perform. Again, much of the precipitation type is variable by a degree or two having a big impact on potential totals. Snow totals around 2 to 4 inches seem most likely for these areas (think Lava Hot Springs, Soda Springs, Georgetown, etc.), but there remains about a 30 percent chance that totals could exceed 5 inches of snow. The wind will also play a role today with gusts of 25 to 35 mph across almost the entire CWA. For areas seeing snow, this will create some blowing and drifting snow which could impact travel conditions. Out across the Arco Desert/INL area there is a 30 percent chance for gusts to exceed 40 mph. There is just enough instability across eastern Idaho today thanks to the passing cold front that the HREF shows a 10 to 20 percent chance for a few rumbles of thunder, too. The activity wraps up quickly this evening/early tonight and we get another little break on Friday before the next round of moisture arrives Friday night into Saturday morning. AMM .LONG TERM...Saturday through next Thursday. Unsettled and seasonably cool weather will continue through the weekend courtesy of a broad H5 trough in place over the WRN CONUS, supporting a mix of rain and snow showers with highs in the 40s/50s. A well defined H5 low off the coast of California on Saturday will ultimately split on Sunday sending a secondary low further north up into the Great Basin keeping precipitation chances going in our area through Sunday night. As this broad trough continues to shift east heading into early next week with a H5 ridge of high pressure building behind in the NE Pacific, conditions will then turn drier and warmer for early next week. Given the current track of this weekend system staying further south along the Idaho/Utah border region, highest precipitation totals as a result will remain further south and east with mostly dry conditions favored in the CNTRL Mountains. The latest QPF forecast remains consistent showing around 0.10-0.40" across SE portions of the Snake Plain/Magic Valley and ERN Highlands and around 0.30-0.90" in the South Hills/SRN Highland with locally higher totals in the Bear River Range courtesy of favorable 700 mb upslope flow over the Wasatch Range. Given temperatures still getting above freezing each afternoon but dropping to near freezing or below at night, we will see a mix of rain and snow in the valleys with best chances for all snow above 6500-7000' where more moderate snow accumulations are expected. There will be the potential for at least a WINTER WEATHER ADVISORY for the Bear River Range where around 10-20" of snow will be possible this weekend. As that aforementioned H5 ridge in the NE Pacific builds in for early next week, we may see some isolated showers continue throughout the day on Monday across the SE Highlands but predominantly dry conditions will return regionwide elsewhere. Temperatures will return to seasonably warm levels starting Tuesday with highs back in the 50s/60s. Further north in the Gulf of Alaska, a series of H5 lows will begin to add pressure to the NRN extent of this ridge feature midweek supporting a return to zonal/NW flow aloft. This will result in precipitation chances back in the forecast starting later in the day Wednesday and continuing into Thursday as a H5 trough passes through the NRN Rockies bringing in a cooler airmass for Thursday with highs back in the 40s/50s. MacKay && .AVIATION...For the 12Z TAFS through 12Z Friday. A mix of rain and snow showers will continue throughout the day today as a cold front works through CNTRL/ERN Idaho supporting MVFR/IFR CIGS/VIS at times. The HREF model probability of thunder shows a 10-20% chance at all terminals with best thunderstorm chances this afternoon and evening. Winds will ramp up during the morning hours with W/SW winds this afternoon peaking around 15-25 kts with gusts to 20-35 kts before winds subside after sunset tonight. Quiet and dry conditions will then return overnight with the potential for areas of low stratus and fog especially where clearer skies are observed behind the exiting cold front. MacKay && .PIH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 9 PM MDT this evening for IDZ060- 066. && $$ ####018004636#### FXUS64 KBRO 280931 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 431 AM CDT Thu Mar 28 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Today through Friday) Issued at 358 AM CDT Thu Mar 28 2024 A dry and tranquil weather pattern is expected to continue through the short term forecast period as influences from a high pressure system remains in place. Gusty southerly winds will be the main show in town on Friday as the surface pressure gradient tightens over the region. Forecast models have backed off on the strength in winds on Friday from the past 24 hours, keeping expected wind gusts (30-40 mph) just under Advisory levels. Sampled low level jet (850 mb) winds range between 20-30 kts. Will allow for the day shift to further evaluate future computer runs to see whether or not an Advisory is needed. Regardless, Friday will still feature breezy conditions with south-southeast winds 20-30 mph gusting up to 40 mph. Temperatures will remain seasonable through the short term period. Daytime high temperatures today will be in the mid to upper 80s (cooler along/near the coast). Overnight low temperatures tonight will be in the upper 50s to mid 60s (warmer along/near the coast). Finally, highs on Friday are expected to be in the low to mid 80s (cooler along/near the coast). && .LONG TERM... (Friday Night through Wednesday) Issued at 358 AM CDT Thu Mar 28 2024 The main concern in this portion of the total forecast continues to be wind. Gulf of Mexico high pressure will interact with low pressure over inland Mexico to create an enhanced pressure gradient, with this gradient anticipated to be the strongest on Monday. As a result, a WIND ADVISORY will possibly be needed on this day for the three immediate coastal counties (Cameron, Willacy, Kenedy). Otherwise, the only other notable event during the period will be the Monday night passage of a cold front. In advance of the front, winds downsloping off of the neighboring higher terrain of Mexico will produce a heat spike, and well above normal high temperatures are a distinct possibility for Monday. Finally, with a breezy to windy onshore flow forecast, there will likely be a MODERATE RISK to HIGH RISK of rip currents at the local beaches for the long term forecast period. && .AVIATION... (06Z TAFS) Issued at 1215 AM CDT Thu Mar 28 2024 Through 06z Friday....VFR conditions are expected to prevail throughout the 06z TAF cycle under sunny skies with maybe a few cirrus clouds at times as a surface high pressure system remains in control over the region. Winds will be out of the east tonight at around 5 kts if not light and variable. On Thursday, winds will shift out of the southeast between 5-15 kts. Winds could begin strengthening Thursday night as the pressure gradient begins to tighten across the region. && .MARINE... (Today through Friday) Issued at 358 AM CDT Thu Mar 28 2024 With high pressure in place today, light winds will yield light to moderate seas and overall favorable marine conditions. Tonight into Friday, a strengthening pressure gradient will generate moderate winds which ultimately will yield moderate seas and more adverse marine conditions. Small craft may need to exercise caution during the day on Friday. (Friday Night through Wednesday) An enhanced pressure gradient will exist over the western Gulf of Mexico during a majority of the period courtesy of high pressure over the Gulf of Mexico interacting with low pressure over inland Mexico. Breezy to strong winds and moderate to rough seas will prevail along the Lower Texas Coast, with Small Craft Exercise Caution and Small Craft Advisory likely to be needed. For the remainder of the period, the Monday night or early Tuesday morning passage of a cold front may produce another burst of Caution or Advisory level winds/seas in its wake. && .PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 83 64 80 68 / 0 0 0 0 HARLINGEN 85 61 82 64 / 0 0 0 0 MCALLEN 87 63 84 67 / 0 0 0 0 RIO GRANDE CITY 87 62 86 65 / 0 0 0 0 SOUTH PADRE ISLAND 76 68 73 69 / 0 0 0 0 BAYVIEW/PORT ISABEL 81 64 78 66 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES...None. && $$ SHORT TERM...Evbuoma-23 LONG TERM/UPPER AIR...Tomaselli-66