Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Thu Sep 29 2022 Valid 12Z Thu Sep 29 2022 - 12Z Sat Oct 01 2022 ...Hurricane Ian weakens after landfall but continues to bring damaging winds, prolific rainfall amounts and life-threatening flash flooding across the north-central portion of Florida Peninsula... ...Ian is forecast to make another landfall across the southeastern U.S. on Friday with strong winds and storm surge near the coast, and widespread heavy rain spreading well inland across the Southeast U.S... ...Cool high pressure system will dominate the eastern half of the country outside of Ian as heat in the West will give way to rain and cooler temperatures moving into the Pacific Northwest and the northern Rockies... Hurricane Ian remain the major weather headline this morning after making landfall near Cayo Costa, Florida yesterday as a category-4 hurricane. Although Ian has weakened considerably while over land, damaging winds are still expected to impact areas well inland as the center of Ina is forecast to traverse the north-central portion of the Florida Peninsula and then emerge into the Atlantic as early as late this morning. Meanwhile, Ian's continued interaction with a front will help focus an axis of prolific rainfall totals of up to 30 inches near and just north of the track of Ian's core circulation. The frontal interaction will gradually cause Ian to lose tropical characteristics. However, when the center of Ian moves into the warm waters of the Gulf Stream later today and into Friday, thunderstorm activities that develop will help maintain the intensity and tropical identity of Ian before a second landfall is forecast later on Friday, bringing strong winds and storm surge near the coast, and widespread heavy rain spreading well inland. After tracking over the Florida peninsula, Ian is forecast to emerge into the Atlantic as a tropical storm on Thursday evening. Albeit weaker, Ian is expected to make a second landfall along the Georgia/South Carolina coast on Friday afternoon, with the main threat being torrential rainfall and coastal flooding, leading to a Moderate Risk of Excessive Rainfall being issued for coastal South Carolina and Georgia, where much as 10 inches of rain may fall. Interaction with the aforementioned frontal boundary north of Ian will help expand the heavy rainfall axis, allowing for heavy amounts to fall well inland as the tropical system moves onshore. Elsewhere, fall-like cool temperatures will continue across the Midwest and Northeast through Thursday as a deep, upper-level trough moves eastward. Highs in the upper-50s and low 60s are expected across the region on Wednesday before slowly warming into the low-to-mid 60s on Thursday and Friday, as the trough continues its eastward progression. Freeze Warnings and Frost Advisories have been issued for parts of the Great Lakes region through Thursday morning, as nighttime temperatures will flirt with and drop below freezing. Across the western U.S., above-average temperatures will remain over the region as a strong upper-level ridge moves eastward. Temperatures are forecast to soar into the 100s and 90s for the desert southwest and interior southern California, with Excessive Heat Warnings and Heat Advisories remaining in effect for the Los Angeles and San Diego metro areas through this evening. Moisture ahead of a Pacific cyclone has begun to move onshore in the Pacific Northwest, bringing a period of unsettled weather inland as well as a general cool down to the region. Rain associated with the system is expected to reach the northern Rockies tonight and into Thursday morning. Another impulse of energy will keep the rain over the northern Rockies later on Thursday with high-elevation wet snow possible over northwestern Wyoming by Friday morning. Meanwhile, some monsoonal moisture is forecast to return near/west of the Four Corners region. Kong Graphics are available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php