Tropical Storm Arthur briefly formed near the middle Texas coast on June 17, hours before wobbling inland near Galveston. However, a precursor low-pressure system delivered heavy rain in parts of southern Texas, followed by a post-tropical deluge from the central Gulf Coast region into the lower Southeast. Totals of 4 to 8 inches or more were common across the Deep South, with higher amounts observed in several spots. Although flash flooding and lowland flooding occurred, overall impacts were muted by antecedent drought, which until recently had spanned the South. Farther north, a series of cold fronts sparked occasional showers and thunderstorms, resulting in localized wind and hail damage but maintaining favorable soil moisture reserves for most Midwestern summer crops. The Plains also received scattered showers, amid variable impacts related to lingering drought on rangeland, pastures, and summer crops. Meanwhile, the Plains’ winter wheat harvest quickly advanced between showers, as the drought-affected crop dried down ahead of the normal pace. In the western U.S., hot, mostly dry weather prevailed. Complications related to Western heat included heavy irrigation demands and a broadly elevated wildfire threat. One of the region’s most significant wildfires, the Iron Fire near Eureka, Utah, ignited on June 19 and quickly burned more than 37,000 acres of grass and chaparral.
Heavy rain across northern New England continued to chisel away at lingering, long-term dryness (D0) and moderate to severe drought (D1 to D2). The most impressive improvement occurred across Maine. Through June 23, month-to-date rainfall rose to 4.98 inches in Portland, Maine. General drought improvement was also noted across West Virginia. Farther east, however, severe drought (D2) expanded in north-central Maryland, amid ongoing short- and long-term precipitation deficits. Through June 23, year-to-date precipitation deficits of more than 5 inches were observed in several Maryland locations, including BWI Airport.
Southeast
Heavy rain resulted in significant reductions in drought coverage and intensity, except across much of Florida’s peninsula and portions of the middle Atlantic States. Rainfall was particularly impressive across the northern tier of Florida and central and southern sections of Alabama and Georgia, with many locations receiving more than 8 inches of rain during the drought-monitoring period. The stunning Southern reversal from drought to wetness was capped by the remnants of Tropical Storm Arthur interacting with a stalled front. On June 21, the U.S. Department of Agriculture indicated that statewide topsoil moisture in agricultural regions was 34% surplus in Alabama, along with 33% in Georgia. However, a significant drought footprint persisted in some areas, including portions of Florida, North Carolina, and Virginia. In fact, USDA noted on June 21 that statewide pastures were rated 53% very poor to poor in both North Carolina and Virginia. On the same date, North Carolina’s corn crop was rated 40% very poor to poor, highlighting both drought and periods of extreme heat. In southern Florida, prominent hydrological issues—such as unusually dry wetlands, leading to wildfires—were reflected by pockets of extreme drought (D3), despite scattered thunderstorms. Additionally, the stage on Lake Okeechobee stood at 9.70 feet on June 21, down 0.23 foot from one month earlier.
South
Downpours related to frontal interactions with tropical moisture, including Tropical Storm Arthur, delivered drought relief but caused local flooding. In fact, the western and central Gulf Coast regions became mostly drought-free, following the latest deluge, with broad one-category improvement noted from eastern Texas into central and southern Alabama, as well as northern Arkansas and western Tennessee. By June 21, with periods of heavy rain still falling, statewide topsoil moisture in agricultural regions had increased to 35% surplus in Louisiana, according to the U.S. Department of Agriculture. The region’s most significant remaining drought existed across parts of Arkansas and environs, along with the northwestern half of Oklahoma.
Midwest
Heavy rain grazed some of the lower Midwest’s remaining drought areas, easing moderate to extreme drought (D1 to D3), especially in Kentucky. Meanwhile, the upper Midwest was a mixed bag of spotty improvement and deterioration, with intensity ranging from abnormal dryness (D0) to severe drought (D2). Between the two areas, rather wet conditions existed. On June 21, according to the U.S. Department of Agriculture, statewide topsoil moisture was rated 43% surplus in Illinois, along with 36% in Missouri, 27% in Indiana, and 26% in Michigan. On that date, USDA reported that roughly two-thirds of the U.S. corn (68%) and soybeans (66%) were rated in good to excellent condition, reflecting mostly favorable Midwestern growing conditions.
High Plains
The region’s eastern states reported drought improvement or unchanged conditions, with a few exceptions. Streaks of heavy rain led to one-category improvement in a swath across central Nebraska and western and central Kansas. However, the rain arrived too late to help winter wheat and has only recently begun to revive drought-stricken rangeland and pastures. With the winter wheat harvest well underway (40% complete, nationally, on June 21), 46% of the crop was rated in very poor to poor condition. More than one-half of the crop was rated very poor to poor in Nebraska (83%), Colorado (63%), and Kansas (55%). On June 21, statewide rangeland and pastures were rated at least one-half very poor to poor in Nebraska (73%), Colorado (63%), and Wyoming (60%). In contrast to areas farther east, drought deterioration was observed in parts of Colorado and Wyoming.
Hot, dry weather boosted irrigation demands and resulted in a broadly elevated wildfire threat. Drought deterioration was commonly observed across roughly the northern half of the region, amid significantly above-normal temperatures and mounting water-supply concerns. However, water supplies are highly basin-dependent and often complicated by water rights and other local, state, or regional regulations. Some of the West’s most significant drought—with embedded pockets of extreme to exceptional drought (D3 to D4)—stretched from Oregon to Wyoming, southward into portions of the Four Corners States. By June 24, at least a half-dozen active Western wildfires had burned more than 10,000 acres of vegetation—three in Utah, two in Nevada, and one in Washington. Additionally, the U.S. Department of Agriculture reported on June 21 that statewide rangeland and pastures were rated 75% very poor to poor in Arizona, along with 63% in Colorado, and 60% in Wyoming.
In Puerto Rico, short-term dryness led to further development or expansion of dryness (D0) and drought (D1 to D2), with severe drought being introduced along and near portions of the southern coast. Impacts in drought-affected areas of Puerto Rico are rapidly developing and extend across several sectors, including agriculture (crop stress) and hydrology (localized water rationing).
Extremely dry conditions continued impacting the U.S. Virgin Islands, with worsening conditions and increasing rainfall deficits supporting a degradation to Severe Drought (D2) throughout the Islands. A tenth of an inch of rain or less fell on the Islands this past week, and only a few scattered locations recorded June-to-date totals exceeding 1” including some spots around Christiansted and Fredericksted, St. Croix. Most locations received less than an inch of rain so far this June (23rd). King airport on St. Thomas received only 0.11” during this period, and on Windswept Beach, St. John, just 0.02” fell, which threatens to break the June record low precipitation total of 0.15” recorded in 1985. For the past 30 days, only about 5 to 10 percent of normal rainfall was observed on St. Croix at Christiansted, Montpellier, and H.E. Rohlsen Aiport; at Windswept Beach and East End on St. John; and at King Airport on St. Thomas. Since May 1, Windswept Beach on St. John recorded 1.91” of rain compared to a normal of 6.08” while 60-day amounts were generally 10 to 35 percent of normal at most locations. Since late April, 4.0” to 5.5” of rain fell on several locations around Frederiksted, St. Croix, but amounts ranged from only 0.6” to locally 2.8” at most sites. 90-day amounts are not quite as markedly dry, but only a few scattered sites recorded more than two-thirds of normal for the period, with most closer to half of normal.
Pacific
In Alaska, an area of abnormal dryness (D0) was added in northwestern Alaska, related to very dry weather since late spring. Dry conditions are on the verge of developing farther east in the Yukon Flats of interior Alaska, based an elevated wildfire threat.
In Hawaii, mostly tranquil weather has prevailed since early June. However, given antecedent spring wetness, Hawaiian drought concerns have not yet emerged.
Koror reported 0.69” of rain last week, making their June total 4.55” to date. Palau International Airport reported a more robust 2.20” of rain last week. Koror is more than 6 inches below normal for the last 30 days, but the 30 days prior to that were about 5.5 inches above normal, so no abnormal dryness or drought exists at this time.
Abnormal dryness (D0) continued across Tinian and Saipan in the Northern Marianas Islands (NMI) despite an uptick in rainfall. Saipan recorded 3.53” last week, but that only brough June-to-date totals to 4.54” due to earlier dryness. In addition, Saipan remains more than 6 inches below normal for the past 60 days. Farther south, Rota and Guam received 2.53” and 3.22” respectively, which on top of earlier rainfall kept dryness at bay. Agat was hit by much heavier rainfall than other locations, recording 13.17” of rain during the past 7 days, but these high amounts were highly localized.
Moderate rainfall was observed across the western Federated States of Micronesia, with 2.79” recorded at Yap and 2.40” at Woleai. Both locations are over 3” below normal for the last 30 days, but prior heavy precipitation has resulted in above-normal 60-day totals at both locations, keeping abnormal dryness out of the region for the time being.
Heavy rain fell on parts of central Micronesia last week. Lukunor observed 5.76” while 6.49” fell on Nukuoro, bringing June-to-date amounts to 19.35” and 12.33” respectively. Farther north, Chuuk recorded only 1.33” this past week, but June-to-date totals exceed 10 inches. To the south, Kapingamaringi reported a moderate 2.31” for the week, but heavier amounts earlier resulted in 17.25” for the month-to-date. With widespread 10 to 20 inch totals received over the past 3-4 weeks, dryness and drought are well at bay for the time being.
Variable rainfall amounts were observed across eastern Micronesia. Just under 2” were recorded at Pohnpei while 5.74” doused Kosrae. This brought June-to-date totals to 6.12” and 7.47” respectively. The region has received 2 to 5 inches less rain than normal over the last 30 days, but prior rainfall continues to keep 60-day totals well above normal. No abnormal dryness or drought is assessed at this time, but the situation will need to be monitored for signs of emerging dryness.
In the northeastern Marshall Islands (RMI), Utirik and Wotje felt a small uptick in rainfall this past week. Utirik recorded 1.54” which, combined with several tenths of an inch during the first half of the month, brought month-to-date amounts to 2.34” for June. Wotje recorded 1.36” for the week and 3.67” so far this June (23rd). Going farther back, totals are slightly below 3’ since March, which is more than enough to keep up with climatology and water demand despite relatively meager amounts in recent weeks. Abnormal dryness and drought are not assessed at this time, but the situation will need to be monitored for continued below-normal weekly precipitation.
Across the northwestern RMI, moderate to heavy rainfall was experienced this past week. Kwajalein reported 4.76” while the weekly amount jumped significantly to 4.21” on Ailinglapalap. This was sufficient to bring an end to short-lived D0 first assessed last week at Ailinglapalap. Kwajalein rainfall for June-to-date reached 9.80” after the wet week, which is over the amount needed to match demand. Thus no abnormal dryness or drought is assessed there.
Farther south and east, moderate to heavy amounts of rain fell on Jaluit (3.23”) and Mili (3.21”) while drier conditions prevailed a bit farther north across Majuro (0.84”). June-to-date totals reached 7.61” on Mili and 6.33” on Jaluit, and with amounts since March topping 40 inches, both locations remained free of dryness and drought. In east-central RMI, Majuro has recorded 4.36” of rain so far this June, and is 4.32” below normal for the last 30 days. Cumulative amounts dating back 60 days or longer are near normal, however, so no abnormal dryness or drought is assessed for Majuro at this time.
On the other side of the Equator, Pago Pago in American Samoa has received a little over 4 inches for June-to-date (4.14”). 30-day amounts are a bit below normal (anomaly -1.54”), but longer-term numbers show some significant surpluses, including amounts about 7.6” above normal for the past 60 days. No dryness or drought is evident across American Samoa at this time.
Looking Ahead
A cool pattern from the northern and central Plains into the Northeast will begin to break down during the weekend, as heat builds northeastward. During the next few days, triple-digit (100-degree) heat will be mostly limited to the southern High Plains and the Desert Southwest. Late in the weekend, however, temperatures could reach 100°F as far north as the upper Midwest and as far east as the Carolinas. Meanwhile, markedly cooler air will overspread the West. Increasingly showery weather will accompany the Western cool spell, particularly from the Pacific Northwest to the northern Rockies, although dry weather will continue in much of California and the Desert Southwest. Unsettled weather will also prevail east of the Rockies, except for hot, dry conditions in the western Gulf Coast region. Five-day rainfall totals could reach 2 to 4 inches or more from the central Plains into the Ohio Valley, and 1 to 2 inches in parts of Montana and North Dakota.
The NWS 6- to 10-day outlook for June 30 – July 4 calls for the likelihood of below-normal temperatures in much of the West, while hotter-than-normal weather will prevail from the Plains to the Atlantic Coast. Meanwhile, near- or above-normal rainfall across much of the country should contrast with drier-than-normal conditions in a few areas, including the Great Basin and portions of the Southeast and Intermountain West.
No comments:
Post a Comment