[Table of Contents][Purpose]
[Editorial Policy]
SUMMARY OF FORECASTS
For ENSO Condition and Other SST:
(Note: The Climate Prediction Center has issued a warm episode advisory.)
Dynamical methods: The Scripps/MPI hybrid coupled model predicts strong warmth for winter
to early spring 1998, dropping to normal by spring/summer '98, very cold by fall '98. The UCLA
hybrid coupled model predicts this El Niño to weaken during the first half of '98. The standard
Lamont Doherty Earth Observatory model predicts somewhat warm conditions lingering this
boreal spring, dissipating and turning to cold by summer and intensifying by fall; the new
(LDEO2) model calls for a continuation of warmish SST through fall 1998. The NCEP coupled
model calls for strong El Niño conditions through spring 1998, moderating by summer, becoming
still weaker by fall. The COLA coupled model forecasts current strong El Niño conditions to
rapidly weaken in spring '98, becoming quite cold by winter 1998-99. The Australian BMRC low
order coupled model predicts moderate to strong El Niño conditions returning to normal by fall
'98 and below normal by winter l998-99. The Oxford coupled model calls for moderate warmth in
winter 1997-98 to weaken by mid-1998; the new model design (predicting change from ICs)
forecasts strong El Niño conditions for winter 1997-98, weakening by late spring.
Statistical methods: CDC's inverse modeling predicts current very strong El Niño conditions to
weaken this boreal spring/summer, becoming well below normal by fall '98; warming northern
tropical Atlantic and Caribbean SST over the next several months. The Univ. of British Columbia
neural net model calls for present warm conditions to return to normal by mid-1998, and become
cold by the end of 1998. UCLA's (M)SSA-MEM predicts the warm Niño 3 SST to decline during
1998 but to remain above normal through fall; and SOI rising but remaining below normal
through fall 1998. NCEP/CPC's CCA predicts strong El Niño conditions for Niño 3.4
(120-170W) through mid-spring 1998, returning to normal late summer '98, becoming cold later
in the year. NOAA's constructed analog model predicts strong El Niño conditions for Niño 3.4 to
decline during spring 1998, becoming slightly cold by fall '98. NCEP's 3-model consolidated
forecast calls for strong El Niño conditions through spring 1998 (peaking early spring), declining
to normal by late summer and to somewhat cold by late fall. The CSU/AOML ENSO CLIPER
model predicts rapidly declining Niño 3.4 SST in spring '98, becoming cool by mid-summer and
moderately cold by winter 1998-99.
For North American Temperature:
Dynamical methods: The NASA GISS SI97 dynamical model forecasts cold in northern Mexico
and southern tier of U.S., warm in most of Canada for winter 1997-98. NCEP coupled model
using predicted SST forecasts warm around Great Lakes and much of Canada and southern and
southeastern Alaska Jan-Feb-Mar '98, below normal in Texas, Florida and southwestern Alaska.
Statistical methods: NCEP/CPC's optimal climate normals predicts warm in East and the West
(esp. Southwest) for Jan-Feb-Mar '98. NCEP/CPC's CCA predicts warm far West, north central
U.S., Great Lakes, southern Alaska and panhandle, cold in Southeast, southern Texas and Hawaii
Jan-Feb-Mar 1998. NCEP/CPC's screening multiple regression predicts warm parts of West and
the Great Lakes, cold much of south and mid-Atlantic for Jan-Feb-Mar '98. The CCA of the
Atmospheric Environment Service in Downsview, Ontario predicts warm for Mar-Apr-May 1998
in nearly all of Canada south of 60N.
For North American Precipitation:
Dynamical methods: The NASA GISS SI97 dynamical model predicts wet for northern Mexico
and southern U.S. for winter 1997-98. NCEP coupled model using predicted SST forecasts wet in
Florida, southern Texas and along Calif. coast Jan-Feb-Mar '98, dry south-central Mexico.
Statistical methods: NCEP/CPC's optimal climate normals predicts dry Ohio Valley, Montana,
wet parts of southern half of U.S. Jan-Feb-Mar '98. NCEP/CPC's CCA predicts dry northern tier
of U.S., Ohio Valley and Hawaii, wet southern Florida, southern Texas, and southern and
southeastern Alaska Jan-Feb-Mar '98. NCEP/CPC's screening multiple regression predicts dry in
Midwest, Ohio Valley and western Montana for Jan-Feb-Mar 98, enhanced rain in Florida, the
Southwest and much of Texas and Plains northward to South Dakota. The CCA of the
Atmospheric Environment Service in Downsview, Ontario calls for dry conditions in southern
Canada west of the Rockies Mar-Apr-May 1998, wet in part of coastal British Columbia, part of
NW Territories and central Quebec.
For Tropical/Subtropical Rainfall:
Dynamical methods: The NASA GISS SI97 dynamical model forecasts wet along Ecuador/Peru
coast winter 1997-98.
Statistical methods: The screening regression of the Dept. of Geography, Univ. of Zululand
predicts dryness in many (not all) areas of southern Africa this 1997-98 summer. The CCA of the
South African Weather Bureau (Pretoria) predicts below-normal '97-98 summer rainfall in much
of South Africa except for certain parts such as the Northeast region. The African Desk/NCEP
CCA predicts below normal rainfall in western southern Africa. The Univ. of Wisconsin neural net
and regression call for slightly dry conditions in the Transvaal of eastern South Africa for summer
1997-98 (for 1954-78 mean). NCEP/CPC's CCA predicts very dry conditions at tropical Pacific
islands west of date line, or far enough north or south of equator east of date line, into boreal
spring 1998; much enhanced rainfall at the more equatorial stations near and east of the date line
through boreal spring.
For 1998 Tropical Storm Activity:
Statistical methods: The CSU LAD regression approach forecasts slightly suppressed Atlantic
tropical storm activity for '98. The Poisson, logistic, and OLS regression models of Florida State
Univ. predict somewhat below normal Atlantic hurricanes, intense hurricanes, and Caribbean
region hurricanes for 1998. The Australian BMRC predicts well below average tropical cyclone
activity in the vicinity of Australia for the 1997-98 season.