Latest Monthly Assessment -
The Monthly Drought Outlook for June is based primarily on initial conditions, climatology, and precipitation forecasts on
time scales ranging from the next 5 or 7 days (from the Weather Prediction Center) to the 6-10 day, 8-14 day, and June Monthly
Outlooks issued by the Climate Prediction Center. Drought is expected to persist or worsen In the West, the southern Rockies,
and the Plains from eastern Colorado and northern Oklahoma southward through Texas. This broad area includes most of the
nationís areas of extreme to exceptional drought (D3 to D4 on the Drought Monitor). Modest drought expansion is forecast in
parts of Texas that are already abnormally dry (D0 on the Drought Monitor) where odds favor below-normal June rainfall. In
contrast, both climatology and precipitation forecasts on all time scales favor a month of generalized drought improvement
from the northern tier of Oklahoma northward through the central and northern Plains and the Midwest. This includes a small
strip of exceptional drought (D4) along the Kansas/Oklahoma border, and substantial areas of extreme drought (D3) in the
central Plains. Elsewhere, above-normal precipitation is expected to end drought in the interior Southeast (near where
Mississippi, Alabama, and Tennessee meet), and a quick, robust start to the wet season should bring an end to drought in
southern Florida. Outside the contiguous 48 states, drought is expected to persist in central Maui, and to develop across the
southern half of the Alaskan Panhandle. This area is already abnormally dry (D0 on the Drought Monitor), and odds favor
below-normal June precipitation.
Tools used in the U.S. Monthly Drought Outlook (MDO) included the official Climate Prediction Center (CPC)
temperature and precipitation outlooks for June 2014, various short- and medium-range forecasts and models such as the 5-day and 7-day
precipitation totals from the Weather Prediction Center, 6-10 day and 8-14 day CPC forecasts, the NAEFS precipitation outlooks,
the soil moisture tools based on the Constructed Analog on Soil (CAS) moisture,
dynamical models (CFSv2, NMME, and IMME), the 384-hour total precipitation forecasts from several runs of the GFS,
climatology, and initial conditions.
Climatologically, June is a very dry month along the West Coast, especially in California. On average, most of the state receives less than 2 percent of its annual rainfall during this month. In southwestern Oregon and in northeastern California (northeast of the Sierra Nevada and east of the Cascades), this climatological average is closer to 4 percent, but in either case, even the wettest Junes wonít make up for significantly below normal precipitation during the prior cold season. In addition, little or no precipitation appears in order through at least the first half of the month region-wide. The odds are overwhelming for drought to persist and perhaps worsen in spots.
Forecast confidence for California and southwest Oregon is very high.
Across the northern half of the Intermountain West (including the northern half of the Great Basin), June is not so markedly dry as in California, but it is somewhat drier than other times of the year in most of the region. However, because of the temperature and humidity this time of year, modeled soil moisture declines more than 75 percent of the time during June, and June 2014 has enhanced chances for above-normal temperatures according to the CPC outlook. The odds slightly favor above-normal precipitation along the southern tier of Idaho during the 6- to 10-day period, but across the remainder of the region Ė and across southern Idaho for other time frames Ė none of the outlooks favors surplus precipitation. In sum, the broad consensus of indicators points to little chance for drought relief, though climatologically it is not as unlikely as in areas farther south and west.
Forecast confidence for the northern half of the Intermountain West is high.
June is a dry time of year across the southern half of the Intermountain West and in the southern Rockies, most markedly through Arizona and adjacent Nevada, where June usually brings less than 2 percent of annual precipitation. The forecasts call for little or no precipitation through the first week of June 2014, and continued below-normal precipitation through the second week of the month as well. For the month as a whole, neither surplus nor deficient rainfall is favored, but climatology and the outlooks for the first half of June both point toward little chance for significant drought relief.
Forecast confidence for the southern half of the Intermountain West and the southern Rockies is high.
Drought is expected to persist in the High Plains of eastern Colorado and New Mexico, and in the Great Plains from all but the northernmost tier of Oklahoma southward through Texas, with some expansion forecast in parts of southern Texas and the southern Big Bend region. Climatologically, this is a wet time of year in the High Plains, the Big Bend region, most of Oklahoma, and northwestern Texas (including the Panhandle). Across the rest of Texas, June is not particularly dry or wet compared to the rest of the year on average, but normal rainfall is significant, ranging from 2 or 3 inches in southern and west-central Texas to over 5 inches in southeastern parts of the state. As a result, there is the potential for significant rainfall and drought improvement in these areas during this time of year. However, the odds favor drier than normal conditions in most of the region for the first half of June 2014, and there are enhanced chances for below-normal precipitation for the month as a whole across southern Texas and the southern tier of the Big Bend. Odds slightly favor above-normal precipitation in east-central and northeast Colorado for June 2014, but historically, modeled soil moisture drops more than 60 percent of the time during the month, and the latest outlooks from the Weather Prediction Center backed off of earlier forecasts for moderate to heavy rain during the first week of the month. So drought persistence is also forecast for most of eastern Colorado because of the soil moisture climatology and the current forecast for only light precipitation early in the month, though with much lower confidence.
Forecast confidence for the southern Plains is moderate, and for the central High Plains is low.
June is a relatively wet time of the year from northern Oklahoma northward and northeastward through the central and northern Plains and the Midwest. This is particularly true from northern and western Kansas northward, where 15 percent or more of the annual precipitation typically falls during June. Looking at the forecasts, several inches of precipitation is forecast across northern parts of this region during the first week of June, and at least moderate amounts are expected elsewhere. Furthermore, the odds favor above-normal precipitation during the second week of June and for the month as a whole. The convective nature of precipitation during this time of the year means there will probably be some parts of the region who miss out on heavy precipitation and drought relief, but the preponderance of indicators point toward heavy rainfall and drought relief to be the general rule across the region.
Forecast confidence for central and northern Plains and Midwest is moderate to high.
For the small area of drought in the interior Southeast near where Mississippi, Alabama, and Tennessee meet, both short- and longer-term forecasts favor above-normal precipitation. Confidence is low because itís tough to boost modeled soil moisture during the month of June climatologically, but it seems somewhat more likely than not that the moderate drought (D1) in the region will be removed by the end of June 2014.
Forecast confidence for the interior Southeast is low.
June is usually the month the wet season kicks in across southern Florida, with a marked increase in precipitation that has boosted the modeled soil moisture a large majority of the time historically. In addition, above-normal rainfall is favored for the first two weeks of June 2014, and for the month as a whole. As a result, drought removal is forecast with high confidence.
Forecast confidence for southern Florida is high.
A small moderate drought area persists on central Molokai in Hawaii, associated with low water levels on the Kualapuu reservoir. The June 2014 forecast is non-committal, but it would take a very wet month to alleviate these low reservoir levels, and the anticipated above-normal temperatures wonít help matters.
Forecast confidence for Hawaii is moderate.
Abnormal dryness (D0 on the Drought Monitor) has developed in the southern Alaskan Panhandle, and below-normal precipitation is favored by the 6- to 10-day, 8- to 14-day, and June monthly outlooks in this region. Thus, conditions are expected to deteriorate, and drought is forecast to develop by monthís end.
Forecast confidence for southeastern Alaska is moderate.